Is it possible for an object moving with a constant speed to accelerate? xm8u-a 0w bdec zmb/53 Explain08b /3wca-b5mmzu ed x.

  Consider a particle moving with constant speed such that its ac ls05thz .8b 6u1jruycceleration of constant magnitude is always perpendicular to its velocc.js zb1hut5l6r 8u0yity.

  An object moves in a circular path at a const ioz3xrg,fxo44)8fmr t3 3nql ffj1b (ant speed. Compare the direction of the object's velocity and acceleration f (o3flitnm8j4zqx3g1)rrx3, of 4 bf vectors.

  When an object experienc) he+5go-v )wk/dppjses uniform circular motion, the direction of the acceleration is )gwj5+hpskp/ov -)de

  Consider a particle moving with constant speed such;7+lrzufac8om fx )x1 that its acceleration of const ;1u)x8r mlac+ozf7xfant magnitude is always perpendicular to its velocity.

  What type of accelerazf csrk*-u eq*/ xvn-+tion does an object moving with constant speed in a circular path experikn-u z*cr+f x*v/ eq-sence?

  What force is needed to make an object move in 5a2;jmq7y 9ox6 :wh9bjl ygkya circle?

  When an object experiences uniform ci8kd39p( swruq3 twus,o onr *7rcular motion, the direction of the net forc7d(or9 s po38tn uk,w3 u*rqswe is

  A roller coaster car is on a track that forms a circular loop in the vertical +7w xwc ,v9 ypi gji)b a0fo)2h*:8vk6ezvlluplane. If the car is to just maintain contact with track at the top of the f aw j )0wvx298v,67lo c )lvkheuiybi: *zp+gloop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car .wpeuzgy9, 7n(mass = M) is on a track that forms a circular loop (radius = r) in the vertical plane.7ypugwen9, z. If the car is to just maintain contact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-cirm2fva oog * ih0xt0wv3f u5l-2cular arc until it is going a205ugo-0hfvtm l ow*vix2 3fstraight up. Just as the plane is at its lowest point, the force on him is

  A coin of mass $m$ rests on a turntable a distance $r$ from the axis of rotation. The turntable rotates with a frequency of $f$. What is the minimum coefficient of static friction between the turntable and the coin if the coin is not to slip?

  A car goes around a curve of --m3 p0i gpn, g h2vrr*ocwi5bradius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius r at a constant speed v.qxg7*s 8.lqye Then it goes around the same cgy8l 7esq.*x qurve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of r o-crnorbn o0 y1uyo(w/+*n4u ir3w6padius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the u/( c 3* wro n-1nyy0 pr4w6r+buonoiocar as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. w x/kvaj(r 5n:(p ce/oxkyc24 If the road is frictionless due to ice, the car can still negotiate the curve if the horizonta4jvc/ar( yn(:ocp xk2/we x5kl component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same ang4ejqg1 x:h7i)zc/ u ejle, but one has twice the radius of the other. e :eiz7cug1h) q4xj/ jThe safe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant9f./ b w;hbg/bm7aed t, but increases upward from the he / bgwf7db.9t/bh; maorizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object 4 kvu4m*,t4fa1qsib /1 z)1oolhx oemmoving around a circular path to have both centripetal and tangential acceleratioo1u) obvemxoz /i4ak4 q 1l1th,*smf4n?

  The gravitational force between two objects 93 i0tjpw u48huma mo,jk.2lj is proportional to

  The gravitational force between two o;a6ri,y9(zqm tz mx :(ijcle *bjects is inversely proportional to

  Two objects attract each other gravitationally. If the distance bebir n0m 2pp82ttween their centers is cut in hal n8pm2ibr0p2 tf, the gravitational force

  Two objects, with masses n:*qx-u ;gl(+g7dx ,x femoqt$m_{1}$ and $m_{2}$, are originally a distance r apart. The gravitational force between them has magnitude F. The second object has its mass changed to 2$m_{2}$, and the distance is changed to r/4. What is the magnitude of the new gravitational force?

  Two objects, with mad rk5kmklpfe5w0b6m -o r6/r0 sses $m_{1}$ and $m_{2}$, are originally a distance r apart. The magnitude of the gravitational force between them is F. The masses are changed to 2$m_{1}$ and 2$m_{2}$, and the distance is changed to 4r. What is the magnitude of the new gravitational force?

State Newton's law of universal gravitatc.+1 ,ycwday sion.

  Compared to its mass on thck(ge( s g:ot lwj+::.59srzrp5c abte Earth, the mass of an object on the Moon is

  The acceleration of gravity on th p2d0y -3gobt/6koqpl e( mbat //o9zhe Moon is one-sixth what it is on Earth. An object ofplh/bo-3z g2t da/6 mq ot k/oebp9(0y mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rockecn*cm p. -gf)qt's weight

  A spaceship is traveling to the Moon. Atzird(6we p 68)levmq ) what point is it beyond the pull of Earth's m6)dwv r8lzq p)6e i(egravity?

  Suppose a satellite were orbiting tupo2.c 1 *7y m+ucik15me cptshe Earth just above the surface. What is its c.eppsc ic 1ctuk17myo* +52muentripetal acceleration?

  A hypothetical planet has a mass of half th .; 0u lyusfnh/ ;dl26d9c qq 6pfxahwa*nu8/oat of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in termslacxq 92y h/adh60 p*/qul; 6;.dwoffnnu8us of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on: hhqiccx5(zwo 2c +/d Earth. The radius of the Moon is one-four+(c co h h:zxcd/2iq5wth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has t6 g 6iie.k5 s1lexm-qdwice the radius of planet A. If planet5 q x .ei6igse6mkd-l1 A has mass m, what is the mass of planet B?

  Two planets have the saail,i1st ui)r-1y f +pme surface gravity, but planet B has twice the mass of planet A. If planet A has radius s1al fiuptii y+,)r- 1r, what is the radius of planet B?

  Consider a small satellite moving in a 3 lnzrr ,p/g/8 jw,hlfcircular orbit (radius r) about a spherical planet (mass M). Whirj 8hr,/wp ,l z3nf/lgch expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and+k5r mp8 o e6fqp)rtxg3y47 gb rotates in the same orbit. Compare the two satellite'sygmt4rf) e57qpgpxr 3k+ 86bo speeds.

  A person is standing on a scale in an elevator accelerating downward. Com7lpwcs g,px,,e 4c:y ue6rli) pare the reading on the scale to the per,4ce 67le cp gr)yi lw,s,p:xuson's true weight.

  Who was the first person to realiz mpn27nlq09iu e that the planets move in elliptical paths arouin72l mp9qnu0nd the Sun?

  The speed of Halley's Comet, whi87 8yjl :f3cphly*jb,bpn;vo le traveling in its elliptical orbit around the Su,bcj8jhvlfl *y;7n:p8 po b3yn,

  Let the average orbital radius of a planet be R. Let the orbital period be T. p1 t ts7jtua-+ What quantity isu p+ttatj1 -7s constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, w h r 4e:m;1:5ao ;tv hkb5+h7 u+r0bgodvujudaith the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the periuhojua 5:4 k1gr;hdueoh ;:a5bbd0v+ + mv7trod of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astr3asy8yc6lc,he u:fg 5onomical unit" (AU). An asteroid orbits ty83elhy: 6acu s5f c,ghe Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. 5 +z 1 wbo:ubh-w9wcek*z;tqi

  List the four fundamental forces ihzl.b o3ocaet v 5 jf.+7uq);en nature.

  An object moves with a constant speed of 30 m/s on a circular track of r0+9bsl yv*fyy6-ic3(jxpd readius 150 m. What is the ijcyylb-6p30fe9 d sx +yr (*vacceleration of the object?

  The maximum speed around ir5twi+ 94lp0 q-tr awa level curve is 30.0 km/h. What is the maximum speed around a curve with twice thlw 5 qipt -9rir4+0wate radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the pe 65q+nf ehtcd.rimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/ hfd+ 5etq6nc.s?

  A point on a wheel rotating at 5.00 rev/s sd u .diguc340s(m:1yj ke+u sis located 0.200 m from the axis. What is the centripetal .:i3sd k1(cm04+ uy ujgsudesacceleration?

  How many revolutions per minute must a circular, rotating space station of ra;ag39 + /vk* 2h0kyrchca fvcwdius 9k/cvky c+fc2 hr0h;wa3gv *a1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.45ohpjz r.w svr r8*d*3bfat zs.py8 2j;3sgn 5 k2vyzr.s 3rstjpjo*; *g f4ds8r5w3b h.naz p8m/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to tsbvz o./:n7 d7w/gjt:fxr8w zhe end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string ctw8 o:znd : vx.7gz/bwjsr/ 7fan withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in1v+ jsm5d2a6u k+kbe,r v bv-uwyn0m* a vertical circle of radius r. At eb0bvn+sryu5v+kd m2* kjv6,1w-um a the exact top of the path the tension in the string is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in u- 0el13wg6mrf2 exc ea vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weight. Thee-rg efu6 xcm1e20 3lw stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 700 8 sxd,z unwbje:cv4g when pulling out of the dive. What is the radius of curvature of , :07subxvcjwd 0zen 8the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of thr.q/ njw-x( t.l0e c eda*hui/e loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat wilj0qx.r n/atd(u e/eh *- .icwth only one-half of his normal weight. How fast is he going?

  The maximum force a pilot ca gy hsjo4srsh :g;;) 3s gkc0l.*c/vwon stand is about seven times his weight. What is the minimum rg /gvso :ys04wlco*3h g)srj;kc;.hsadius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius how7br d2*.ztvhp4 sf ezrs:(h0 rizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.rtfeh 27 zs hb.( 4vs*0dprwz:)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/xfn 3df; b03ut rsn07as. The centripetal force provided by friction n rf n tab0uf330dsx7;is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50z /hosv vn5o5jw0e( 60let* am m at a speed of 14 m/s. What must be the m/n5 e*ve(ht0a v0 5o zomsj6lwinimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant0.n ;g3 x,xepbwfs(cf speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. (,sxfpf;w3x nc0ge b. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 100a vw5 ,in **y(zfexhy7-:ofog -m radius turn at 35 m/s without sy iyh(*g:a z 5owfex, *v7-fonkidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a*,i6;i j q;/h dfirdv6qliwwc t6+a mb./nt,t $45^{\circ}$ angle. When a bobsled rounds this curve at the curve's safe speed (no friction needed to stay on the run), what is its centripetal acceleration?

  A frictionless curve of radius 100 mxh/.*ot do(; ylws+h c, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80i;rv r0(0/l ewn3okry k 71bef m is banked at $45^{\circ}$. Suppose that an ice storm hits, and the curve is effectively frictionless. What is the safe speed with which to take the curve without either sliding up or down?

  A 175-kg ball on the end of a string is revolving ugfkcq88thfnt+q7rx648tgn 8x f y1 +oniformly in a horizontal circle of radt nh8q4ktoqtx+nc6gygf81x + 78f 8 frius 0.500
m. The ball makes 2.00 revolutions in a second. (only fill in numerial value in the blanks)
(a) Determine the speed of the ball.    $m/s$
(b) Determine the ball's centripetal acceleration.    $m/s^2$
(c) Determine the force a person must exert on opposite end of the string.    $N$

  Starting from rest in the pit area, a race car,l )e y7o8;w, ,numtvkz/qrbq accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value ,/rn,u,q zove;lwqb 7y k8t)min the blanks)
(a) Calculate the tangential acceleration.    $m/s^2$
(b) Calculate the radial acceleration when the instantaneous speed is equal to 30 m/s.    $m/s^2$

  The hydrogen atom cog:. a4 x+jazlznsists of a proton of mass $1.67 \times 10^{-27} \; kg$ and an orbiting electron of mass $9.11 \times 10^{-31} \; kg$. In one of its orbits, the electron is $5.3 \times 10^{-11} \; m$ from the proton. What is the mutual attractive force between the electron and proton?

  What is the gravitational foi+9hjauq7b.)tsn e/ h7nb i o9rce on a 70-kg person standing on the Earth, due to the Moon? The mass of the Moon is bn.)u9 itqhsh e ia7jb7+n 9o/$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If the masses are mcz: c /t-jvz5)u.fj zae qwb64oved to half of their initial divczw5uj- 4z ta 6/) jzcf:e.qbstance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distano4v.ue)ef8 b vce from the Earth will )4f.eb 8ve vouthe gravitational forces due to the Sun and the Earth cancel?
Earth's mass: Me = $5.98 \times 10^{24} \; kg$ the Sun's mass: Ms = $1.99 \times 10^{30} \; kg$
Earth-Sun distance: r = $1.50 \times 10^{11} \; m$

  The mass of the Moon35. q1-lxn0p otzk/1 fvcxobm is $7.4 \times 10^{22} \; kg$ and its mean radius is $1.75 \times 10^{3} \; km$. What is the acceleration due to gravity at the surface of the Moon?

  An astronaut goes out fpzq +yd.96mr cor a "space-walk" at a distance above the Earth equal to the6yqpczd mr.9+ radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above thqa )tzf0b yxky 2n/t5ydf,p3 -9r5 zfpe Earth's surface will the acceleration of gq pn,a9yzpt f55y)-x 2tk/3 z0yf dbfrravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to dbktnt lxa4n v/h5*k6.:j f5f3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of * :hbn k6ltfjdfnaxvt4/.55kMars, is

  At a distance of 14000 v3qo/ 5d0x *a90w 8ruzbrco nokm from some planet's center, the acceleration of gravity is rcao0xv8*r zbu/ 3n50qoo 9dw$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface of the Earth. The Easp t gsre/ttc w.0sx02*sf++trth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is its weigf2scr0s 0tt/w.+ +get xpst* sht?

  By how many newtons does the weight of a 100-kg person chs4u80oydd0u l ange when he goes from sea level to an altitude4ou y0ud0dsl 8 of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite 49+q c maf ski72*cerqaudz,8of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weigue2az fmscqkir + 8q*,9a7dc4 ht?

  A spherically symmetric planet has four times the Earth's mass and twice ii ucanwo+14a:**g zayts radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surfaceca * aio+*gwayn:4 zu1 of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all liwbpuapap :-mla:9*lk9 7b5rjk k-5 j se on the same line, with the Earth between the Moon and the u57kp a b-:k abp mw-kspjjrl 9a:9l*5Sun. The Moon has a mass of $7.36 \times 10^{22} \; kg$; the Earth has a mass of $5.98 \times 10^{24} \; kg$; and the Sun has a mass of $1.99 \times 10^{30} \; kg$. The separation between the Moon and the Earth is given by $3.84 \times 10^{8} \; m$; the separation between the Earth and the Sun is given by $1.496 \times 10^{11} \; m$.
(a) Calculate the force exerted on the Earth by the Moon, its magnitude is    $\times 10^{20} \; N$, its direction is  ----待选择----towardsaway from  the moon.
(b) Calculate the force exerted on the Earth by the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.
(c) Calculate the net force exerted on the Earth by the Moon and the Sun, its magnitude is    $\times 10^{22} \; N$, its direction is  ----待选择----towardsaway from  the Sun.

  A 2.10-kg brass ball is transported to tmsypp9pe(kcw( -*q 25cgl 6bla* nyvaj5 ; xj,he Moon.
(a) Calculate the acceleration due to gravity on the Moon.    $m/s^2$ (The radius of the Moon is $1.74 \times 10^{6} \; m$ and the mass of the Moon is $7.35 \times 10^{22} \; kg$)
(b) Determine the mass of the brass ball on the Earth    $kg$ and on the Moon    $kg$
(c) Determine the weight of the brass ball on the Earth    $N$
(d) Determine the weight of the brass ball on the Moon    $N$

  A satellite is in a low circular orbit about tl-xgi7qt okiej48vs)7 )mx b,fr3 b 2lhe Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth )tj4 g l)oxx7qi smbl ,ie-k8vb2rf73is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about tp tueyj7xxa 9g 0b:(54*gt mujhe Earth (i.e., it just skims the surface of the Earth). 9uajtmgg:e 4 x5t0uxjb7*p(yHow long does it take to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. It isptf (,mv5d0 xjl*kqv7 observed to have a period of 89 min. What is the mass of the Eardlpvm 5x jv0,tq(*7fk th? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter,m(r. t0btgwj3h9mr pz m)(s+u has an orbital diameter of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupi xnqa8 x7fpk,3ter orbits the planet with a radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearb1acf 5h )h,6ze 0ge4 /unuflely circular orbits. Moon A has orbital radius r, and moon B has orbita4/la fb fu5e hu,n zge)06ec1hl radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is .k cqk zhij3js-xn84ai.mo.+$7.78 \times 10^{11} \; m$ from the Sun. How long does it take for Jupiter to orbit once about the Sun? (The distance from the Earth to the Sun is $1.50 \times 10^{11} \; m$.)

  It takes the planet Jupiter 12 years to orbit the Sun l,lombu:w8/g once. What is the average distance from Jupiter to the Sun? (The distance from the Ear8 :,w/olumglb th to the Sun is $1.5 \times 10^{11} \; m$.)