题库网 (tiku.one)

 找回密码
 立即注册

 

      

上传图片附件

未使用图片

小贴士: 允许的图片文件格式为: gif, jpg, jpeg, png, webp,上传完成后会在上方生成预览,用鼠标连续双击缩略图,或拖动缩略图,该图片就被绑定至本题,显示在题目下方

本次作答已使用

小贴士: 此栏目显示的是当前作答使用的所有图片,绑定到某一题目的图片同时会显示在该题目下方; 删除使用的图片会将其转移到<未使用图片>类别


习题练习:gc physics textbook chapter 5 problems



 作者: admin   总分: 118分  得分: _____________

答题人: 匿名未登录  开始时间: 24年10月30日 17:35  切换到: 整卷模式

标记此题
1#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Sometimes people say thaj a h,vmmq:3 h.-bt1fmktc/r(6 q8;jbti-q pwt water is removed from clothes in a spin dryer by centrifugalc1rp-/m jiqq.t,ma( qt86wtmf -bb ;j:3vhhk force throwing the water outward. What is wrong with this statement?
参考答案:    

标记此题
2#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Will the acceleration of a car be the same when the car travels around a sharp ci2rb17:yc2ymva qqx+ urve at a constant 60 kmyiq2 m 7c+qyx a2rv1:b/h as when it travels around a gentle curve at the same speed? Explain.
参考答案:    

标记此题
3#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Suppose a car moves at constant speed along a hilly road. W1kh9 ;,pg amdfgn/h,nu+9ni phere does the car exert the greatest and least forces on the road: (a) at the nmk/f 9,d 19+i ;hnphpggna,utop of a hill, (b) at a dip between two hills, (c) on a level stretch near the bottom of a hill?
参考答案:    

标记此题
4#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Describe all the forces acting on a child ridinlwz 2ea)u9quw- ae+f(g a horse on a merry-go-round. Whu+92q aw w l()-aueefzich of these forces provides the centripetal acceleration of the child?
参考答案:    

标记此题
5#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A bucket of water can be whirled in aqrb/1e+fc m3d vertical circle without the water spilling out, even at the fq/3r+cd1mbe top of the circle when the bucket is upside down. Explain.
参考答案:    

标记此题
6#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
How many “accelerators” do you have in your car? There are at least three contjvw :vnudhz7i ms)e889s:(jtdfhs -,rols in the car which can be used to cause the car to accelerate. What are they? What accelerations do they produce- 9fhv:sjv sn)jw8duhdsim(e zt:8 7,?
参考答案:    

标记此题
7#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A child on a sled coma8 3/afhcdaw3 tp*zv:es flying over the crest of a small hill, as shown in Fig. 5–31. His sled does not leave the ground (he does not achieve “air”), but he feels the normal force between his chest and the sled decrease as he goes over the hill. Explain this decrease using Newtoadh wfcv 3/3 za*at8p:n’s second law.

参考答案:    

标记此题
8#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Why do bicycle riders lean inward when rounding a curve at hy3a bow nmi47b)zh 2)pigh speed?
参考答案:    

标记此题
9#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Why do airplanes bank when they turnqge ,jtzb67f8 ? How would you compute the banking angle given its speed an8 ef6 qbgjt,7zd radius of the turn?
参考答案:    

标记此题
10#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A girl is whirling a ball on a string around her2; . de1wadus76frrbv head in a horizontal plane. She wants to let go at precisely t;s7 1wvru arde f2b6.dhe right time so that the ball will hit a target on the other side of the yard. When should she let go of the string?
参考答案:    

标记此题
11#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Does an apple exert a gravitational force on the Earth? If so, how large audmd )4ahu3otl *-sd, force? Consider an au-t, 3os dlhdud 4*a)mpple
(a) attached to a tree, and (b) falling.
参考答案:    

标记此题
12#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
If the Earth’s mass were double what it is, in what ways would the Moon’s orbit* *o2iu8,yr2 0eha+2avu ltw oaffjj: be di*2aa2,w8r ifahlu+0fe*jojuyt 2 o :vfferent?
参考答案:    

标记此题
13#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Which pulls harder g5r(osn)hvvpz5 yx5p,mws 3 1 iravitationally, the Earth on the Moon, or the Moon on the Earth? Which accy 5si,v5)wp rs1z5(movn hx p3elerates more?
参考答案:    

标记此题
14#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The Sun's gravitatio.vwhr-3 cn q-znal pull on the Earth is much larger than the Moon's. Yet th3znr--. qhv wce Moon's is mainly responsible for the tides. Explain. [Hint: Consider the difference in gravitational pull from one side of the Earth to the other.]
参考答案:    

标记此题
15#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Will an object weigh more at the equator or at tha *w qzt,8-+bktz9 ib,tms pf-e poles? What two effects are atqas- p+-w,8bkzb t*mtfz, t9i work? Do they oppose each other?
参考答案:    

标记此题
16#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The gravitational force on the Moon due to the Ear v8swx8uq3 m 6sy2c6;cm i8lyeth is only about half the force on the Moon due t v8 sy3e628x m6sqiumyw8;c clo the Sun. Why isn’t the Moon pulled away from the Earth?
参考答案:    

标记此题
17#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Is the centripetal acceleration of Mars in its orbit ad ;eirzd o4c)0i1ek +lround the Sun larger or smaller than the centripetal acceleration of the Ear led )i+i0e4d;1ozkcrth?
参考答案:    

标记此题
18#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Would it require less speed to launch a satellite (a) toward the east or (b) to(:wy;hz6 bq ozward the 6:q h;yo(zzw bwest? Consider the Earth’s rotation direction.
参考答案:    

标记此题
19#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
When will your apparent weight be the greatest, as measu+ o k2o* .plhqtdlxi:er(s z04red by a scale in a moving elevator: when the elevator (a) accelerates downward, (b) accelerates upward, (c) is in free fall, (d) moves upward atx(s h*:r0i q+oezk p dtl2ol.4 constant speed? In which case would your weight be the least? When would it be the same as when you are on the ground?
参考答案:    

标记此题
20#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
What keeps a satellite up in its orbit around theEarth?
参考答案:    

标记此题
21#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Astronauts who spend long periods in outer space could be adversely affecte*- t -yhrsso5fd by weightlessness. One way to simulate gravity is to shape the spaceship like a cylindrical shell that rotates, with the astronauts walking on ths--of 5rh s*tye inside surface (Fig. 5–32). Explain how this simulates gravity. Consider (a) how objects fall, (b) the force we feel on our feet, and (c) any other aspects of gravity you can think of.
参考答案:    

标记此题
22#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Explain how a runner experiences “free f;,owyp7v4l7m(5y gvgo 2hhr hall” or “apparent weightlessness” between steps.pgg7 l(myv yhh74or oh2;5,vw
参考答案:    

标记此题
23#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The Earth moves faster in hdr;f efdu yv*vb3f o6.i*s*2its orbit around the Sun in January than in July. Is the Earth closer to the Sun in January, or in July? Explain. [Note: This is not much of a factor in producing the seasons — the main factor is the tilt of .d;voef6 d vryb3f2ui fs** h*the Earth’s axis relative to the plane of its orbit.]
参考答案:    

标记此题
24#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
The mass of Pluto was not known until it was discovered to have a moon. Exp33mo xzs l8 vvu+pw)7nlain how this discovery enabled an estimate of Pluto’s mass. x7v s8+lvnzo m)w3pu3
参考答案:    

标记此题
25#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Sun's gravitational pull on the Earth is much larger than tizsc)iedw9u+ta. j f2k( l 1;she Moon's. Yet the Moon's is mainly responsible for the tides. Explain. [Hint: Consider the difference in gravitational pull from one side of the Earth to the other.]A child sitting 1.10 m from the center of a merry-go-round moves with a speed of 1.2diiaut jz )fsskw ; +c.291e(l5 $\mathrm{~m} / \mathrm{s}$ . Calculate (a) the centripetal acceleration of the child,   
(b) the net horizontal force exerted on the child ( mass =25.0 $\mathrm{~kg}$)   

参考答案:     查看本题详细解析

标记此题
26#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A jet plane traveling rp15imx (0tm: in3pjh 1980 $\mathrm{~km} / \mathrm{h}(525 \mathrm{~m} / \mathrm{s})$ pulls out of a dive by moving in an arc of radius 6.00 km . What is the plane's acceleration in $g^{\prime}$ 's?    g's

参考答案:     查看本题详细解析

标记此题
27#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Calculate the centripetal acceleration of the Earth in itscag 2oyb b(-/g*bnut) orbit around the Sun, and the nobu*a yb bngg2t- c()/et force exerted on the Earth. What exerts this force on the Earth? Assume that the Earth's orbit is a circle of radius 1.50$ \times 10^{11} \mathrm{~m}$ . [Hint: see the Tables inside the front cover of this book.]    $\times10^{22}$

参考答案:     查看本题详细解析

标记此题
28#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal force of 210 N is exerted on a 2.0-kg discus as it rotij+,sau 1ur4l ates uniformly in a horizontal circle (at arm’s length) of radiuluj4a s +r,1ius 0.90 m. Calculate the speed of the discus.   

参考答案:     查看本题详细解析

标记此题
29#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose the space shuttle is in orbit 400 km from lt9pe+qmz 7 oh5e hr8(the Earth's surface, and circles the Earth a (l opr9t5mqzh8eeh7 +bout once every 90 minutes. Find the centripetal acceleration of the space shuttle in its orbit. Express your answer in terms of g , the gravitational acceleration at the Earth's surface. $\approx$    g

参考答案:     查看本题详细解析

标记此题
30#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the magnitude of the acceleration o/lzf(scu0w.* jzfu. qf a speck of clay on the edge of a potter’s wheel turning at 45 rpm (revolut zuulfsq(z0.*/cj.f wions per minute) if the wheel’s diameter is 32 cm?   

参考答案:     查看本题详细解析

标记此题
31#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A ball on the end of a string is revolved at a uniform rate in a +l5rta)s k+ce o1 w3q.;)gba)xc0kif- wrbce vertical circle of radius 72.0 cm , as shown in Fig. 5-33. b)eg bl1+-ca)3 c qr)kwe. 5wxsak ;r0iotc+fIf its speed is 4.00 $\mathrm{~m} / \mathrm{s}$ and its mass is 0.300 kg , calculate the tension in the string when the ball is (a) at the top of its path   
(b) at the bottom of its path.   


参考答案:     查看本题详细解析

标记此题
32#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 0.45$-\mathrm{kg}$ ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.3 m on a frictionless horizontal surface. If the cord will break when the tension in it exceeds 75 N , what is the maximum speed the ball can have?   

参考答案:     查看本题详细解析

标记此题
33#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the maximum speed with which a 1050sluq lq hq5(jtcyu5p-n(;wyepwgn6 ,9k7(w+ -kg car can round a turn of radius 77 m on a flat road if tcywpnenltl+ 75 9-6;,g (qu qk(( pu jqw5wyhshe coefficient of static friction between tires and road is 0.80? Is this result independent of the mass of the car?   

参考答案:     查看本题详细解析

标记此题
34#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How large must the coefficientox- 0hbkrf)m8rvgxrme;; 3:d of static friction be between the tires and the road if a car is to round a level curve of radius 85 m : d ghb;-xr8ro mx ev0f);mk3rat a speed of 95km/h ?   

参考答案:     查看本题详细解析

标记此题
35#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A device for training astronauts and jet fighter 3urv (9d(qcoopilots is designed to rotate a trainee in a horizontal circle of radius 12.0 m . If the force felt by the trainee on her backc(o3dq (our9v is 7.85 times her own weight, how fast is she rotating?    rev/s    m/s
Express your answer in both $ \mathrm{m} / \mathrm{s}$ and $\mathrm{rev} / \mathrm{s}$ .

参考答案:     查看本题详细解析

标记此题
36#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coin is placed 11.0 cm from the axis of a rotating tu(fq6f00rln 9 vd qxtj8rntable of variable speed. When the speed of the turntable is slowly increased, the coin remains fixed on the turntable until a rate of 36 rpm is reached aq0 0vx(6 f8tq9ndlfjrnd the coin slides off. What is the coefficient of static friction between the coin and the turntable?   

参考答案:     查看本题详细解析

标记此题
37#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what minimum speed must a roller coaster be traveling wheo0plar*fjzl kukfm+za3.29*,, tgft n upside down at the topkt m.trz*ol+fk,afp2 0 39g,lf z uaj* of a circle
(Fig. 5-34) so that the passengers will not fall out? Assume a radius of curvature of 7.4 m .   

参考答案:     查看本题详细解析

标记此题
38#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  (II) A sports car of mass 950 kg (ins3msiged:-c h)ijc 6)cluding the driver) crosses the rounded top of a hill (radms: )3 c -idhj6is)egcius =95$ \mathrm{~m}$ ) at 22 $\mathrm{~m} / \mathrm{s}$ . Determine
(a) the normal force exerted by the road on the car,   
(b) the normal force exerted by the car on the 72-kg driver   
(c) the car speed at which the normal force on the driver equals zero.   

参考答案:     查看本题详细解析

标记此题
39#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How many revolutions per minute would a 15-m-diameter Ferris wheel z2v mw 8*hp9trb(g7euneed to make for the passengers to feel “weightless”ut(bph9r* zm7v e8 2wg at the topmost point?    rpm

参考答案:     查看本题详细解析

标记此题
40#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bucket of mass 2.00 kg is whirled in a vertical circle of radius 1.10 m.6wg9 iv4 wgk:p At the lowest point of its motion the tension in the rope suppo g64gpv9k :iwwrting the bucket is 25.0 N.
(a) Find the speed of the bucket. $\approx$   
(b) How fast must the bucket move at the top of the circle so that the rope does not go slack?   

参考答案:     查看本题详细解析

标记此题
41#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How fast (in rpm) must a cexu4a vw.us cc.*:r+gdpetk7,ntrifuge rotate if a particle 9.00 cm from the axis ocvra.*dps cw, egxu u:t.7k 4+f rotation is to experience an acceleration of 115,000 $\mathrm{~g} $'s?    rpm

参考答案:     查看本题详细解析

标记此题
42#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a "Rotor-ride" at a carnival, people are rotlmk/w,j. 7b4ks9jr no ated in a cylindrically walled "room." (See Fig. 5-35.)osw4 nb mj9k/7jk .,lr
The room radius is 4.6 m , and the rotation frequency is 0.50 revolutions per second when the floor drops out. What is the minimum coefficient of static friction so that the people will not slip down? People on this ride say they were "pressed against the wall." Is there really an outward force pressing them against the wall? If so, what is its source? If not, what is the proper description of their situation (besides "scary")? [Hint: First draw the free-body diagram for a person.]   


参考答案:     查看本题详细解析

标记此题
43#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A flat puck (mass M ) is rotated in a circle on a frictionless air-hockey tadf(jcu44s8 g *5;z qmd-fjpebbletop, and is held in this orbit by a light cord connected to a dangling block (mass m ) throughc fzg8;ue-4bq(jdfs dm4* p5 j a central hole as shown in Fig. 5-
36. Show that the speed of the puck is given by

$v=\sqrt{\frac{m g R}{M}}$

参考答案:    

标记此题
44#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Redo Example 5-3 , precisely this time, by notyh a0bogkspwl+zj0 :(a :k+, w ignoring the weight of the ball which revolves on a string 0.600 m long. In particular, f( +0apazbw:l o +y0wg,jks k:hind the magnitude of $\overrightarrow{\mathbf{F}}_{\mathrm{T}}$ , and the angle it makes with the horizontal. [Hint: Set the horizontal component of $\overrightarrow{\mathrm{F}}_{\mathrm{T}}$ equal to m $a_{\mathrm{R}}$ ; also, since there is no vertical motion, what can you say about the vertical component of $\overrightarrow{\mathbf{F}}_{\mathrm{T}}$ ?] $\overrightarrow{\mathbf{F}}_{\mathrm{T}}$ =    the angle =   

参考答案:     查看本题详细解析

标记此题
45#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a curve with a radius of 88 m is perfectly banked for u1tqv 5 7t9p:f iob3o ci9wr+hk5xuz ;a car traveling 75 $\mathrm{~km} / \mathrm{h}$ , what must be the coefficient of static friction for a car not to skid when traveling at 95 $\mathrm{~km} / \mathrm{h}$ ?   

参考答案:     查看本题详细解析

标记此题
46#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 1200$-\mathrm{kg}$ car rounds a curve of radius 67 m banked at an angle of 12$^{\circ}$ . If the car is traveling at 95$ \mathrm{~km} / \mathrm{h}$ , will a friction force be required? If so, how much and in what direction? $\approx$    down the plane

参考答案:     查看本题详细解析

标记此题
47#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Two blocks, of massewsb tiw85.. fbs $ m_{1}$ and $m_{2}$ , are connected to each other and to a central post by cords as shown in Fig. 5-37. They rotate about the post at a frequency f (revolutions per second) on a frictionless horizontal surface at distances $r_{1}$ and $r_{2}$ from the post. Derive an algebraic expression for the tension in each segment of the cord.

参考答案:    

标记此题
48#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pilot performs an evasive maneuver by divij*l3o mtoan7 0ng vertically at 310 $\mathrm{~m} / \mathrm{s}$ . If he can withstand an acceleration of 9.0 g 's without blacking out, at what altitude must he begin to pull out of the dive to avoid crashing into the sea?   

参考答案:     查看本题详细解析

标记此题
49#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Determine the tangential and centripetal componenu,a/ hj6bl -lnts of the net force exerted on the car (by the ground) in Exampl- ablj6,unh /le 5-8 when its speed is 15$ \mathrm{~m} / \mathrm{s}$ . The car's mass is 1100 kg . F$_{tan}$ =    F$_R$ =   

参考答案:     查看本题详细解析

标记此题
50#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A car at the Indianapolis 500 accelerates u8uh2a84 bhhn uniformly from the pit area, going from rest to 320km/h in a semicircular arc with a radius of 220 m. Determine the tangential and radiau4h8ahub2 8hnl acceleration of the car when it is halfway through the turn, assuming constant tangential acceleration. If the curve were flat, what would the coefficient of static friction have to be between the tires and the road to provide this acceleration with no slipping or skidding? $\approx$   

参考答案:     查看本题详细解析

标记此题
51#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A particle revolves in a horizontal circle of radius 2.90 m g)( j( dfloyl3. At a particular instant, its acceleration is y) (fll( ojg3d 1.05 $\mathrm{~m} / \mathrm{s}^{2}$ , in a direction that makes an angle of 32.0$^{\circ}$ to its direction of motion. Determine its speed (a) at this moment   
(b) 2.00 s later, assuming constant tangential acceleration.   

参考答案:     查看本题详细解析

标记此题
52#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Calculate the force of Earth’s gravity on a spacecraft 12,800 km (2 Eardy w ufz8e*ra2(3u c4rth radii) above the Ear 3rwrezd24 f8 ya(*cuuth’s surface if its mass is 1350 kg.   

参考答案:     查看本题详细解析

标记此题
53#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At the surface of a certain planet, the gravitational acpr7gb41t lm zwjs5c*) 2 *lbfoceleration g has a magnitude of 12 24bg 5 zc*s*w 1)of7rtjpllmbm/s$^2$ A 21.0-kg brass ball is transported to this planet. What is (a) the mass of the brass ball on the Earth and on the planet   
(b) the weight of the brass ball on the Earth and on the planet? $W_{Earth}$   $W_{planet}$  

参考答案:     查看本题详细解析

标记此题
54#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Calculate the accelerationly )l 1,ntlhl; due to gravity on the Moon. The Moon's radius is 1.74lntl,;hyl )l 1 $\times 10^{6} \mathrm{~m} $ and its mass is 7.35 $\times 10^{22} \mathrm{~kg}$ .   

参考答案:     查看本题详细解析

标记此题
55#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A hypothetical planet has a radius 1.5 times thm l7thr 2 )yh,c ntsd,3a0m)h)a*qqpf at of Earth, but has the same mass. What i,q3))rlfad h7t y qm,mpthn0a*ch )s2s the acceleration due to gravity near its surface?   

参考答案:     查看本题详细解析

标记此题
56#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A hypothetical planet has a mass 1.66 times that of 1yc:oo47xvvx.xrg2pq 6uh, lEarth, but the same radius. What is g nex,v1uq lxrhx o: y7vog2.6c4par its surface?   

参考答案:     查看本题详细解析

标记此题
57#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two objects attract each other gravi4j:juf*- u6+ealfy, anno,h eq v,*oatationally with a force of 2.5$ \times 10^{-10} \mathrm{~N}$ when they are 0.25 m apart.
Their total mass is 4.0 kg . Find their individual masses. m$_1$ =    m$_2$ =   

参考答案:     查看本题详细解析

标记此题
58#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Calculate the effective value of g , the a j r9:5b:5nxpqpux f,lcceleration of gravity, at (a) 3200 m5 , n j:bfp5ql:xxrup9    , and (b) 3200 km    , above the Earth's surface.

参考答案:     查看本题详细解析

标记此题
59#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is thedistance from the Earth’s center to a point outside xda5z oy e.cws4y bj45bj2l/s*. d-dg the Earth where thegravitational acce/ o5s a .jd - z*.dgceby5xj44dlb2ywsleration due to the Earth is $\frac{1}{10}$ of its value atthe Earth’s surface?   $\times10^7$

参考答案:     查看本题详细解析

标记此题
60#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A certain neutron star has five times the mass of our Sun packed into a sphered)2+ezvs-5qey2qw o0 qjjxfw:d ba7 3 about 10 km in radius. Estimaqfa2)w:j3we7jqse+ x5-o y0d qdv2b zte the surface gravity on this monster.    $\times10^12$

参考答案:     查看本题详细解析

标记此题
61#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A typical white-dwarf star, which once was an average star like our Sbn x,v+c9 s 7zy yb:kqm2x:wy6un but is now in the last stage of its evolution, is the size of our M6xwk 9y7mz: sqxv2bc y:+ynb,oon but has the mass of our Sun. What is the surface gravity on this star?    $\times 10^7$

参考答案:     查看本题详细解析

标记此题
62#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are explaining why astronauts feel weightless while orbiting in the heb(hxx 1g; ism 3vk1rk t)o6ir1nq2.space shuttle. Your friends respond that they thought gravity was just a lot weaker up there. Convince them and yourself that it isn’t so by calculating the acceleration of gravity 250 k kio rxirbhem kgn()1qsv.;1hx1t632 m above the Earth’s surface in terms of g.   

参考答案:     查看本题详细解析

标记此题
63#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Four 9.5-kg spheres are located at the corners of a sa0 j 2vojx6wa-cya4 5vquare of side 0.60 m. Calculate the magnitude and direction of the tot j6xavaw 04v5cj-ya 2oal gravitational force exerted on one sphere by the other three.   $\times 10^{-1} \mathrm{~N} \text { at }$    $^{\circ}$

参考答案:     查看本题详细解析

标记此题
64#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Every few hundred years most of the planets line up on the same s 16zocjgvk4q l8u( 3x :lamtt;jdem;,ide of the Sun. Calculate the total zcl dljxokvu m 36jq(t4,1t8g;;me a:force on the Earth due to Venus, Jupiter, and Saturn, assuming all four planets are in a line (Fig. 5-38). The masses are $M_{\mathrm{V}}=0.815 M_{\mathrm{E}}, M_{\mathrm{J}}=318 M_{\mathrm{E}}, \quad M_{\mathrm{S}}=95.1 M_{\mathrm{E}}$ , and their mean distances from the Sun are 108,150,778 , and 1430 million km , respectively. What fraction of the Sun's force on the Earth is this? $F_{Earth-planets}$ =   $\times 10^{17}$ ${F_{Earth-plantes}}$ \ ${F_{Earth-sun}}$=    $\times 10^{-5}$

参考答案:     查看本题详细解析

标记此题
65#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Given that the acceleration of gravity at the surfacewz9 )xm(u y;jphrad8 -;c e5zq of Mars is 0.38 of what it is on Earth, and that Mars’rzchx5- )e9;d qmz y;8u(jpwa radius is 3400 km, determine the mass of Mars.    $\times 10^{23}$

参考答案:     查看本题详细解析

标记此题
66#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Determine the mass of td5zsk j 3,,d//lqgucdtu )td:he Sun using the known value for the period of the Earth and its distance from the Sun. [Note: Compare your answer to that obtained using Kepk l3uus/qgj)td/ , :cdz d,td5ler’s laws, Example 5–16.]    $\times 10^{30}$

参考答案:     查看本题详细解析

标记此题
67#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Calculate the speed of a satellite moving in a stable circular orbit ab lye, 2 p9j9pydr12dzpout the Earth at a height of 3600 km1el9 d y292zd yjppp,r.    $\times 10^3$

参考答案:     查看本题详细解析

标记此题
68#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The space shuttle releases a satellite into aih: i2*txq p76jgqg3x circular orbit 650 km above the Earth. How fast must the shuttle be moving (relative to Earth) when the release occurs?h x j2x3 *6itg:igqq7p    $\times 10^3$

参考答案:     查看本题详细解析

标记此题
69#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what rate must a cylindrical spaceship rotate if 8kb5y-v wxxlrkowb0 9cbr /0/occupants are to experience simu8w/kkrx/-b vbcxlwy 0br 950olated gravity of 0.60 g? Assume the spaceship’s diameter is 32 m, and give your answer as the time needed for one revolution. (See Question 21, Fig 5–32.)   


参考答案:     查看本题详细解析

标记此题
70#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Determine the time it takes for a satellite to orbit th u jit;+bgbm,9 7xnhu n k.ge+bdz044 ferb/z3e Earth in a circular “near-Earth” orbit. A “near-Earth” orbit is one at a height above the surface of the Earth which is very small compared to the radius of the Earth. Does your result de +ugznbz fb+ ir,d93/je4b.xhu ;ekgnm74t 0bpend on the mass of the satellite?    s ~    min

参考答案:     查看本题详细解析

标记此题
71#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what horizontal velocity would a satellite have to c:cpapsz k072w gyo6-6 q(7 bh+blirzbe launched from the top of Mt. Everest to be placed in agb(k7+how a :6 y-qlzri0 czcp62s7b p circular orbit around the Earth?   

参考答案:     查看本题详细解析

标记此题
72#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  During an Apollo lunar landing missioncmqyxt sgc h 5h38 +m9te5(nd3, the command module continued to orbit the Moon at an altitude of (98t 53tyd+ex mg5h 3scm nhqcabout 100 km. How long did it take to go around the Moon once?    s

参考答案:     查看本题详细解析

标记此题
73#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The rings of Saturn are composed of chunks of ice that orbit the p-zo1 c1xzb :k5incy ah9 gjm:-lanet. The inner radius of t yj1 m1o a:-cn5hz:gx9-kbciz he rings is 73,000 $\mathrm{~km}$ , while the outer radius is 170,000$ \mathrm{~km}$ . Find the period of an orbiting chunk of ice at the inner radius and the period of a chunk at the outer radius. Compare your numbers with Saturn's mean rotation period of 10 hours and 39 minutes. The mass of Saturn is 5.7 $\times 10^{26} \mathrm{~kg}$ .


$T_{\text {irner }} $ =   
$T_{\text {outer }} $ =   

参考答案:     查看本题详细解析

标记此题
74#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A Ferris wheel 24.0 m in diameter rotates once every 15.5 s (see Fig. 5–9). e yhx);k) hmnhvk+ o:,What is the ratio of a person’s apparent weight to her real weight (a) at the top, and (b) ahv);m,kyn x+ h) oekh:t the bottom?
(a)    (b)   

参考答案:     查看本题详细解析

标记此题
75#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the apparent weight of a 75-kg astronaut 4200 km from the center of tl(;zf 6r7k:f n wvu5xeyx1i c:he Earth's Moon in a space vehicleex 1v:nfi (;x56y7w kczr:ulf (a) moving at constant velocity,     
(b) accelerating toward the Moon at 2.9 $\mathrm{~m} / \mathrm{s}^{2}$ ?     

State the "direction" in each case.

参考答案:     查看本题详细解析

标记此题
76#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that a binary-star system consists of t,nkle)r74gci;6sh:o*n ce h n wo stars of equal mass. They are observed to be separated by 360 million km and take 5.7 Earth years to orbit aboic;nngk er6h c*len 7o,) :h4sut a point midway between them. What is the mass of each?    $\times 10^{29}$

参考答案:     查看本题详细解析

标记此题
77#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What will a spring scale read for the weight of a 55-kg9: omzf-bsumk k,/rbsoly(ud6*42a x woman in an elevator that moves u:m yaf(6 oulb z2sk*xkod9b,m4s/-r
(a) upward with constant speed of 6.0m./s   
(b) downward with constant speed of 6.0m./s   
(c) upward with acceleration of 0.33 g,   
(d) downward with acceleration 0.33 g   
(e) in free fall?   

参考答案:     查看本题详细解析

标记此题
78#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 17.0-kg monkey hangs from a cord suspended from the ceili13t(s0o2 tgyrwggj f8 jsuh++ ng of an elevator. The cord can withstand a ten2jws0r u+j(g+t gfhygt 813sosion of 220 N and breaks as the elevator accelerates. What was the elevator’s minimum acceleration (magnitude and direction)? a =   

参考答案:     查看本题详细解析

标记此题
79#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Show that if a satellite orb+ 1krq rgnmtulf,08:cits very near the surface of a planet with period T , the density (maln8u:k+ cg0fmq1r,r t ss/volume) of the planet is $\rho=m / V=3 \pi / G T^{2}$ .
(b) Estimate the density of the Earth, given that a satellite near the surface orbits with a period of about 85 min .
参考答案:    

标记此题
80#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Use Kepler’s laws and the perio)ta,d+gg-9xi6v*do/zxa c xod of the Moon (27.4 d) to determine the period of an artificial satellite orb)d6gc, g+z9iv ad/x* xt-o oxaiting very near the Earth’s surface.    s

参考答案:     查看本题详细解析

标记此题
81#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The asteroid Icarus,zg0(ri/ 3y6 jgs uio1d though only a few hundred meters across, orbits the Sun like the planet60zgii jog(u1/ ryds 3s. Its period is 410 d. What is its mean distance from the Sun?    $\times 10^{11}$

参考答案:     查看本题详细解析

标记此题
82#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Neptune is an average distance s:clzh jd018fg,mv4 z of 4.5 $\times 10^{9} \mathrm{~km}$ from the Sun. Estimate the length of the Neptunian
year given that the Earth is 1.50 $\times 10^{8} \mathrm{~km}$ from the Sun on the average.    $\times 10^2$

参考答案:     查看本题详细解析

标记此题
83#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Halley’s comet orbits the Sun roughly once every 76 years. ogx 4wq y(y;l cgu.;y6e4qh*cIt comes very close to the surface of the Sun on its closest approach (Fig. 5–39). Estimate the greatest distance of the comet from the Sun. Is it still “in” the Solar System? What planet’4wc . h*;(eoyq64;xlqgguy cys orbit is nearest when it is out there? [Hint: The mean distance s in Kepler’s third law is half the sum of the nearest and farthest distance from the Sun.]    $\times 10^6$


参考答案:     查看本题详细解析

标记此题
84#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Our Sun rotates about the center of the G3b k2z v)ss)imalaxy $\left(M_{G} \approx 4 \times 10^{41} \mathrm{~kg}\right)$ at a distance of about 3 $\times 10^{4}$ light-years $\left(1 \mathrm{ly}=3 \times 10^{8} \mathrm{~m} / \mathrm{s} \times 3.16 \times 10^{7} \mathrm{~s} / \mathrm{y} \times 1 y\right)$ . What is the period of our orbital motion about the center of the Galaxy? $\approx$   $\times 10^8$

参考答案:     查看本题详细解析

标记此题
85#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Table 5–3 gives the mass, period, and meav gnwy-ru* h:zxhk2q )8*jjl+n distance for the four largest moons of J: krlq2g)nhxvwj*8j+hz - u*y upiter (those discovered by Galileo in 1609).
(a) Determine the mass of Jupiter using the data for Io.$M_{\substack{\text { Jupiter- } \\ \text { Io }}}$ =    $\times 10^{27}$
(b) Determine the mass of Jupiter using data for each of the other three moons. Are the results consistent?
$M_{\substack{\text { Jupiter- } \\ \text { Europa }}}$ =    $\times 10^{27}$
$M_{\substack{\text { Jupiter- } \\ \text { Ganymede }}}$ =    $\times 10^{27}$
$M_{\substack{\text { Jupiter- } \\ \text { Callisto }}}$ =    $\times 10^{27}$

参考答案:     查看本题详细解析

标记此题
86#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Determine the mass of the Earth 05h zrb8 ra;+8dlo rcxfrom the known period and distance of the Moon. odlb850zr r+r chx8; a   $\times 10^{24}$

参考答案:     查看本题详细解析

标记此题
87#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Determine the mean distance from Jupiter for each of Jup((m,w:kf adyw+n at..tt o6ekiter’s moons, using Kepler’s third law. Use the distance of Io and the periods given in Table 5–3. Compkan(w tt,ma6def .k + y(w.:toare to the values in the Table.
$r_{\text {Farip }}^{r}$ =    $\times 10^3$
$r_{\text {Guarymale }}$ =    $\times 10^3$
$r_{\text {Culimio }}$ =    $\times 10^3$

参考答案:     查看本题详细解析

标记此题
88#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The asteroid belt betonv6x5 7+syht ween Mars and Jupiter consists of many fragments (which some sp6 +ovyn5 sx7thace scientists think came from a planet that once orbited the Sun but was destroyed).
(a) If the center of mass of the asteroid belt (where the planet would have been) is about three times farther from the Sun than the Earth is, how long would it have taken this hypothetical planet to orbit the Sun?$\approx$    y
(b) Can we use these data to deduce the mass of this planet?

参考答案:     查看本题详细解析

标记此题
89#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A science-fiction tale describes an artificial "planetbu q y*v( 7lyg)1jlod.qk3tp* d,; yvb" in the form of a band completely encircling a sun (Fig. 5-40). The inhabitants live on the inside surface (where it * ly1v 7yjo* g.qbvpk (tyuq);3db,ldis always noon). Imagine that this sun is exactly like our own, that the distance to the band is the same as the Earth-Sun distance (to make the climate temperate), and that the ring rotates quickly enough to produce an apparent gravity of g as on Earth. What will be the period of revolution, this planet's year, in Earth days?   


参考答案:     查看本题详细解析

标记此题
90#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Tarzan plans to cross a gorge by swinging in an arc from a hanging vine(pyi)xdeu(*23* ljtoii 9 tsc5 yfi0r (Fig. 5–41). If his arms are capable of exerting a force of 1400 N on the vine, what is the maximum speed he can tolerate *io(3 t(uiclfy0 e5 xtp idsy i*9)rj2at the lowest point of his swing? His mass is 80 kg, and the vine is 5.5 m long.   


参考答案:     查看本题详细解析

标记此题
91#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How far above the Earth’s surface will the acceleration of gravity be half7 1 rwpn1,s5qo495yak m ulwrs what it is on thurn5or1k wp sal7 45,wq91msye surface?    $\times 10^6$

参考答案:     查看本题详细解析

标记此题
92#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  On an ice rink, two skaters of equabn/3k8 s fs(0lykxki9 l mass grab hands and spin in a mutual circle once every 2.5 s. If we assume t/b0fsys(3kxk 8 ln 9kiheir arms are each 0.80 m long and their individual masses are 60.0 kg, how hard are they pulling on one another?    $\times 10^2$

参考答案:     查看本题详细解析

标记此题
93#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Because the Earth rotates once per day, the app:y4z7qild )iqy)0yr *x alc 6narent acceleration of gravity at the equator is slightly less than it would be if the Earth didn’t rotate. Estimate the magnin70c zlqi)r4ld): aq y 6x*yiytude of this effect. What fraction of g is this?    $\times 10^{-1}$

参考答案:     查看本题详细解析

标记此题
94#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what distance from the E+8q zj 7l925luifrfxs3wl8v carth will a spacecraft traveling directly from the Earth to the Moon experience zero net force because the Earth and Moon pl z83+u9fvci 285wfrljs7lxq ull with equal and opposite forces?    $\times 10^8$

参考答案:     查看本题详细解析

标记此题
95#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You know your mass is 65 kg, but when you stand on a bathroom scale in an 0pocy 47d xjy(elevator, it says your mass is 82 kg. What is the acdc(oj40x7 y pyceleration of the elevator, and in which direction?     

参考答案:     查看本题详细解析

标记此题
96#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A projected space station consists of a civ * a w;x00wcr-itvt- fr-rku6rcular tube that will rotate about its center (like a tubular bicycle tire) (Fig. 5–42). The circle formed by the tube has a diameter of about 1.1 km. What must be the rotation speed (revolutions per day* a-fvr0 vx-6ck0wr; ti- urwt) if an effect equal to gravity at the surface of the Earth (1.0 g) is to be felt?$\approx$    $\times 10^3$





参考答案:     查看本题详细解析

标记此题
97#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A jet pilot takes his aircraft in a vertical loop3x3 riz lwl-i;s vz:f03w4gjv (Fig. 5–43).
(a) If the jet is moving at a speed of at the lowest point of the loop, determine the minimum radius of the circle so that the centripetal acceleration at the lowest point does not exceed 6.0 g’s.    $\times 10^3$
(b) Calculate the 78-kg pilot’s effective weight (the force with which the seat pushes up on him) at the bottom of the circle    $\times 10^3$
(c) at the top of the circle (assume the same speed).
   $\times 10^3$


参考答案:     查看本题详细解析

标记此题
98#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Derive a formula for the mass of a planet in terms pa5ucmj ufj cns;sls ,d6836-of its radius r, the acceleration due to gravity atpjf da5 ,cmjs;ns3lu8s6-u c6 its surface and the gravitational constant G.
参考答案:    

标记此题
99#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A plumb bob (a mass m hanging on a stringzn)u fpj f4.ie/o5mw4) is deflected from the vertical by an ang.wie/pf44muj)o f5 znle $\theta$ due to a massive mountain nearby (Fig. 5-44). (a) Find an approximate formula for $\theta$ in terms of the mass of the mountain, $m_{\mathrm{M}}$ , the distance to its center, $D_{\mathrm{M}}$ , and the radius and mass of the Earth. (b) Make a rough estimate of the mass of Mt. Everest, assuming it has the shape of a cone 4000 m high and base of diameter 4000 m . Assume its mass per unit volume is 3000 kg per $ \mathrm{m}^{3}$ . (c) Estimate the angle $\theta$ of the plumb bob if it is 5 km from the center of Mt . Everest.
参考答案:    

标记此题
100#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A curve of radius 67 m is banked for a design speed of If the coefficin3; )jnbaag c4*dlh*fay6/ xf ent of static friction is 0.30 (wet)a l*x/fc;fadnbayh * g346j n pavement), at what range of speeds can a car safely handle the curve?
参考答案:    

标记此题
101#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How long would a day be if the Earth were rotating so fast that objects at the5gx*xns; (h nxxp89ep7welp 4 equator were apparently xp l5phg9*x 8np 47xwexens ;(weightless?    $\times 10^3$s

参考答案:     查看本题详细解析

标记此题
102#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Two equal-mass stars maintain a constant distance apm /*fvji145v -wvu rzvart of 8.0 $\times 10^{10} \mathrm{~m} $ and rotate about a point midway between them at a rate of one revolution every 12.6 yr . (a) Why don't the two stars crash into one another due to the gravitational force between them?
(b) What must be the mass of each star?    $\times 10^{26}$

参考答案:     查看本题详细解析

标记此题
103#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A train traveling at a constant speed rounds a curve of radius 235 m. A lamp sx .surtto2r+37mgt/: 1 a*reu0goqskuspended from the ceiling swingsm.0ro:u q7taxtuo /tr 1 2rsgg k3e*s+ out to an angle of 17.5$^{\circ}$ throughout the curve. What is the speed of the train?   

参考答案:     查看本题详细解析

标记此题
104#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Jupiter is about 320 times as massive as the Earth. Thus, i ij7/frajfw-a*i5 rw 9t has been claimed that a person would be crushed by the force of gravity on a planet the size of Jupiter since people can't survive more than a few g 's. Calculate the number of g 's a person wo-wj ia5w9 *arjrf7 if/uld experience at the equator of such a planet. Use the following data for Jupiter: mass =1.9 $\times 10^{27} \mathrm{~kg}$ , equatorial radius =7.1$ \times 10^{4} \mathrm{~km}$ , rotation period =9 $\mathrm{hr} 55 \mathrm{~min}$ . Take the centripetal acceleration into account.    g's

参考答案:     查看本题详细解析

标记此题
105#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Astronomers using the Hubble Space Telescope deduced the presh: i-gac3wr03 1xqbjin p6il:ence of an extremely massive core in the distant galaxy M87, so dense that it could be a black hole h i0 x-wbn36:1gqc a3pl: jiri(from which no light escapes). They did this by measuring the speed of gas clouds orbiting the core to be 780 $\mathrm{~km} / \mathrm{s}$ at a distance of 60 lightyears $ \left(5.7 \times 10^{17} \mathrm{~m}\right)$ from the core. Deduce the mass of the core, and compare it to the mass of our Sun. v =    $\times 10^{39}$solar masses =    $\times 10^9$

参考答案:     查看本题详细解析

标记此题
106#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A car maintains a constant speed as it traverses t8( c pw(gly6 ;aclzm9ahe hill and valley shown in Fig. 5–45. Both the hill and valley have a radius of curvature R. (a) How do the normal forcesgczaycl 9 w;68(a(pml acting on the car at A, B, and C compare? (Which is largest? Smallest?) Explain. (b) Where would the driver feel heaviest? Lightest? Explain. (c) How fast can the car go without losing contact with the road at A?

参考答案:    

标记此题
107#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Navstar Global Positioning System (GPS) utilizes a group oljmso6( 2 yzqhg(mg.5f 24 satellites orbiting the Earth. Using “triangulation” and signals transmitted by these satellites, the position of a receiver on the Earth can be determined to within an accuracy of a few centimeters. The satellite orbits are distributed evenly around the Earth, with four satellites in each of six orbits, allowing continuoo j65(s2lmz.yq hg(mgus navigational “fixes.” The satellites orbit at an altitude of approximately 11,000 nautical miles [1 nautical ]. (a) Determine the speed of each satellite.    $\times 10^3$
(b) Determine the period of each satellite. =    hours

参考答案:     查看本题详细解析

标记此题
108#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Near Earth Asteroid R0liw l od5sopg)x7 c12endezvous (NEAR), after traveling 2.1 billion km, is meant to orbit the asteroid Eros at 57)lds cpwlio10gx 2oa height of about 15 km . Eros is roughly 40 $\mathrm{~km} \times 6 \mathrm{~km} \times 6 \mathrm{~km}$ . Assume Eros has a density (mass/volume) of about 2.3 $\times 10^{3} \mathrm{~kg} / \mathrm{m}^{3}$ . (a) What will be the period of NEAR as it orbits Eros? $\approx$    $\times 10^4$sec
(b) If Eros were a sphere with the same mass and density, what would its radius be? $\approx$    $\times 10^3$
(c) What would g be at the surface of this spherical Eros?$\approx$    $\times 10^{-3}$

参考答案:     查看本题详细解析

标记此题
109#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are an astronaut in the space shuttle pursuing a satellite in need of 002vp3tvrvjxc yj; y2repair. You are in a circular orbit of the 3ptj vcyr xv02; 0vy2jsame radius as the satellite (400 km above the Earth), but 25 km behind it.
(a) How long will it take to overtake the satellite if you reduce your orbital radius by 1.0 km?$\approx$    h
(b) By how much must you reduce your orbital radius to catch up in 7.0 hours?$\approx$    $\times 10^3$

参考答案:     查看本题详细解析

标记此题
110#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The comet Hale-Bopp has a )ftot.nafuzmnv1 3/c( 3z .j zperiod of 3000 years. (a) What is its mean distance from the Sun? 1 j3(u3/nzz)tnz.vmfot.c af   
(b) At its closest approach, the comet is about 1 A.U. from the Sun ( from Earth to the Sun). What is the farthest distance?   
(c) What is the ratio of the speed at the closest point to the speed at the farthest point? [Hint: Use Kepler’s second law and estimate areas by a triangle (as in Fig. 5–29, but smaller distance travelled; see also Hint for Problem 59).]   


参考答案:     查看本题详细解析

标记此题
111#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Estimate what the value of G would need to be iff 3 onzt-h)x ohg5y;+b you could actually "feel" yourself gravitationally attracted to someone ne3o5hz- bg yx)nfho+t;ar you. Make reasonable assumptions, like F $\approx 1 \mathrm{~N}$ .    $\times 10^{-5}$

参考答案:     查看本题详细解析

标记此题
112#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The Sun rotates around the center of the Milky Way Galaxy (*nolr0u6 b t,ct 16+tlm.ayqfFig. 5-46) at a distance of about 30,0ytl+buanm tr*1cq0t 6fl o ,.600 light-years from the center $ \left(1 \mathrm{ly}=9.5 \times 10^{15} \mathrm{~m}\right)$ . If it takes about 200 million years to make one rotation, estimate the mass of our Galaxy. Assume that the mass distribution of our Galaxy is concentrated mostly in a central uniform sphere. If all the stars had about the mass of our Sun $\left(2 \times 10^{30} \mathrm{~kg}\right)$ , how many stars would there be in our Galaxy?$\approx$    $\times 10^{11}$



参考答案:     查看本题详细解析

标记此题
113#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Four 1.0-kg masses are located at the 5) y 5 t+36w xlhrl djtuzdtb/:h2h*4ta7oegg corners of a square 0.50 m on each side. Find the magnitude and direction of the gravitational fauzhll2t6hg +3e5dg btx7*5h t/:oyw 4 rtj)dorce on a fifth 1.0-kg mass placed at the midpoint of the bottom side of the square.    $\times 10^{-10}$  

参考答案:     查看本题详细解析

标记此题
114#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A satellite of mass 5500 kg orbits the Earth ocf1n2ico8s g drg 79+$ \left(\operatorname{mass}=6.0 \times 10^{24} \mathrm{~kg}\right)$ and has a period of 6200 s . Find (a) the magnitude of the Earth's gravitational force on the satellite, $\approx$    $\times 10^4$
(b) the altitude of the satellite.    $\times 10^5$

参考答案:     查看本题详细解析

标记此题
115#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the acceleration experienced by the tip of the 1.5-cm-long sweep s ocr/ tw /qfqsp.2v.5cu71ps gecond hand on yovoppt. 5 q/c2 gc1wqru7sfs /.ur wrist watch?    $\times 10^{-4}$

参考答案:     查看本题详细解析

标记此题
116#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  While fishing, you get bored and sryk-*hc n68o7m8biwn: q8loz tart to swing a sinker weight around in a circle below you on a 0.25-m piece of fishing line. The weight makes a complete circle every 0.50 s. What is the angle that the fishing line makes with the vertical? 6b 8lrhqomy izn8:-*7kn8 ow c[Hint: See Fig. 5–10.]    $^{\circ}$

参考答案:     查看本题详细解析

标记此题
117#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
A circular curve of radius R in a new hgobqp7fu2 jy;3. y;a highway is designed so that a car traveling at s;yhoy aq g;p.b3fj7 2upeed $ v_{0}$ can negotiate the turn safely on glare ice (zero friction). If a car travels too slowly, then it will slip toward the center of the circle. If it travels too fast, then it will slip away from the center of the circle. If the coefficient of static friction increases, a car can stay on the road while traveling at any speed within a range from $v_{\min }$ to $v_{\max }$ . Derive formulas for $ v_{\min }$ and $ v_{\max } $ as functions of $\mu_{s}, v_{0}$ , and R .
参考答案:    

标记此题
118#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Amtrak’s high speed train, the Acela, utilizes tilt of theud+yjoay 3 zf(,8:f bwd,ge46 qb 9*jmh lcp.w cars when negotiating curves. The angle of tilt is adjusted so that the main force exerted on the passengers, to provide the centripetal acceleration, is the normal force. The passengers experienmfoh jg86 w,+bud:qa3bd y4* jy 9(wfpz lec.,ce less friction force against the seat, thus feeling more comfortable. Consider an Acela train that rounds a curve with a radius of 620 m at a speed of (approximately ). (a) Calculate the friction force needed on a train passenger of mass 75 kg if the track is not banked and the train does not tilt. $\approx$    $\times 10^2$
(b) Calculate the friction force on the passenger if the train tilts to its maximum tilt of 8.0º toward the center of the curve.$\approx$    $\times 10^2$

参考答案:     查看本题详细解析

  • :
  • 总分:118分 及格:70.8分 时间:不限时
    未答题: 已答题:0 答错题:
    当前第 题,此次习题练习共有 118 道题
    本系统支持习题练习,作业与考试三大模式,作业考试自动评分,成绩排序一键导出,可设定动态变量同一试卷千人千题
    如果您对本系统感兴趣,想加入我们或者想进行任何形式的合作,请加微信 skysky1258

    浏览记录|使用帮助|手机版|切到手机版|题库网 (https://tiku.one)

    GMT+8, 2025-5-19 20:17 , Processed in 0.372333 second(s), 258 queries , Redis On.