Is it possible for an object moving with 2 il k0z;dwq.whgo, ksb ,0k.za constant speed to accelerate? Explain.bh gs k.wzdkq.,, wzkol 0;02i

  Consider a particle moving with constant speed such that its acceleratoy-xsa0 u,x)hion of constant magnitude is alxu 0-ysx)h,oaways perpendicular to its velocity.

  An object moves in a circular path at a consta:kolj4lbl7 .h* 7-7mnnfo*t guvs:bant speed. Compare the direction of the object's velocity and acceleration vubakonm l- js.o7l: : 7vnbh4l*f7t*g ectors.

  When an object experiences us 4csqqk-rm9 gh* x):vniform circular motion, the direction of the acceleration iksr:)g*m-4vqq s 9hxcs

  Consider a particle movingnrl)4er3 (-twop rv)9og2sij with constant speed such that its acceleration of constant magnit32 9o ovjtpir4rw -)r(egn)lsude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constan)g:ekpmkbe6 (o fv 76crji.t:t speed in a circular path exp:mk.)jekv7ot c6fi6: bepg (r erience?

  What force is needed to make an objel ++ o8:bh/ hwpjgt,9x ao:pqz.s o7pdct move in a circle?

  When an object experiences uniform circular motion, the direction of the net kbu p,):xtb1dq x*myzck+3 d7for17z+ :bk,tcpyd3 xud mxb*qk)ce is

  A roller coaster car is on a track that forms a circular loop in the6g//fnw b6dahx:)fex7gd +m z vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this pointa/fg6dfzgh:x )+/6d mebwx7n?

  A roller coaster car (mass 8md44yu6qxudz a :gk* = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the ayd:gdk8 z4u64qm*ux loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc unt sosl;ore k u5u09e*at qh)z+-xt6r 7lil it is going straight up. Just as tzqe;rue slu+67 xoakl)s 59h or0*t-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 dtjwki)d hrfp18 mmp vmd( t/0+ih24*radius $r$ 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. Thena 3dlb:dht: ozwzmt4;7k n*2a it goes around the same curve at half of the original speed. What is the cenntahd mz237kzba*d; :: o4lw ttripetal 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 rart h7rf:4+qzfa)01bb viu.j rdius 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 car as it goes aroui)rbvtbjuf: fz 7a1r+0 .hr4qnd the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If thq fe pv(i-aus*, qv8g.e road is frictionless due to ice, the car can still negotiate the curve iq vug*(ivap q-8f.s,ef the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on ashr.er(yt-r.t6cu iw/ 6 p+gd bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the s+.r-rdt6g6 .h r/s(tcwp yei umaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic b*ui 3lljwo6k,3yh ed- obsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intelwkid ejh3luyo 3*-6,ntionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circpg8rb ,j(x4xdfo*b.s b d,+x)fng+ csular path to have both centripetal and tangentialbd+b8c 4fbdps ng sj,xrfgo,)*x(x +. acceleration?

  The gravitational force between n)yu51fq/eymc. *d zl two objects is proportional to

  The gravitational force be /gbao+,luy i.tween two objects is inversely proportional to

  Two objects attract each ot5bbupshwf991 her gravitationally. If the distance between their centers is cut in half, the grav9h5 s1f bwp9buitational force

  Two objects, with massesvj .y.oy 7bp:6e7faa a $m_{1}$ 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 massh0 ;hf8hl xfk iq7zgza8e 2a.6es $m_{1}$ 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 gravitati qkt-:wi rlm96on.

  Compared to its mass on the Earth, the mass of an 58- ey-be((39 sa bb omhgubimobject on the Moon is

  The acceleration of grlmz *;y o4 6ljbcd3fa-avity on the Moon is one-sixth what it is on Earth. An object of ayd cl3z*6mf b-;o4ljmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weighthi6 y iivcq ei:80w3;l

  A spaceship is traveling to thehg-wms62mdm)ef /wc2pj 5 i u) Moon. At what point is it beyond the pull of Earth's gra- )/cefw62isp mgju25m)mdhwvity?

  Suppose a satellite were orbiting the Ear7z2l8adx2 yzs0a: ko rth just above the surface. What is its centripetal accelerationxa7802o alkz:yr sz2d?

  A hypothetical planet has a mass of half that of the Earte:*knoict2c,h v d 6uyfb62v3h and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleratiocb vn2:ck y ui6,ho23*t 6vfden due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what yz/ ) iv(y;nkcit is on Earth. The radius of the Moon is one-fourth tha y;ikz/)vny(c t 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 twicr0/;py2v ysyt e the radius of planet A. If 0yp;rts/v 2yy planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the masl/5lss4/9uy2 a6 c*szzn jumts of planet A. If planet A has radius r, what is the rad2 sz/ucy4m 9lzj*s /las5tn u6ius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheav ( 5u.r4mskpmu*/ czrical planet (mass M). Which expression give*4/kp.ua ucmm vzsr(5s this satellite's orbital velocity?

  Satellite A has twice t: ;kepn4cg8pse1 8nu e ;m2d6dnok kv5he mass of satellite B, and rotates in the same orbit. Com1:g 8 muekec5dvn 4s6;pepkkd2 non;8pare the two satellite's speeds.

  A person is standing on a scale in an elevator acceleratz a yyd:d:78dcing downward. Compare th::7a dzy8cydd e reading on the scale to the person's true weight.

  Who was the first person to realize that the planets move in ell)ijmptzr 8fc i8(x.; diptical paths around th fi8r;.cd(8xm jtpz i)e Sun?

  The speed of Halley's v;itf2 k rfqx+ 7jl(6 g,p0jae;sg0dc Comet, while traveling in its elliptical orbit around the j ,x;gctk qesd 670 j0+vfr(2lgi;pafSun,

  Let the average orbital radius of a planet be R. Let the ow o) o7uecaw;isdvo )l0+o-* p 9frb.drbital period be T. What quanwd o)e;v a-sodorli ufw+*c7 0o9 )pb.tity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the, j6 m1 2onbrhzh2vh+k shmz1 v6r+o hh ,j2b2kname orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the period 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 "astgj)*t z e1,ku w9+ubdbeqdi()ronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's a( g9buk ue1 t*b,jq+edid z))wverage distance from the Sun?

State Kepler's laws.zrp9.uej,jylh5 w 72q

  List the four fundamental forces in nature.b xnf7(gcyz;ng w1 16k

  An object moves with a constant speed of 30 m/s on a circular track of radi5 clgpzzxg -24us 150 m. What is the acceleratioz4p5gc2 gzl x-n of the object?

  The maximum speed around a level curve is 30.0 km/h. What is th )q7hnd4gy 6oke maximum speed around a curve with twice the radius? (Assume all other factorkg7 hq 6n)ydo4s remain unchanged.)

  What is the centripetal acceleratioy dyugs 9yg1re65)fa1 n of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movr yy151e6 y )ug9fgsading 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.fr+stps 6q1 ogj- i (,wtd6m8v200 m from the axis. What is thetf(1oj g8svd6, q p 6istwm+r- centripetal acceleration?

  How many revolutions per minute must m .qov )3bzn9g6pl1+,rrdczo a circular, rotating space station of radius 1000 rg)1pm+vn,dlb z9o6 r3ocz.qm 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 ah+;c zsnzm7)n t 96.5 km/h. What is the centripetal force on the motorcmc7z hn;zns)+ycle?

  A 0.50-kg mass is att usiw0q2 3d4ceached to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that thi s30qwu 4dce2e string can 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 ig sudpgod7; mu8x)t) nv7i-:string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stout))pi:o ng 7svdi gm;dx78-u ne's speed at this point is given by

  A stone, of mass m, is attached to a strong string aw uf//zi /tr-und whirled in a vertical circle of radius r/ /uf/zriw- ut. At the exact bottom 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 jet plane flying 600 m/s experiences an accele j-f*xk :/ t(.b jvmbp2.uxmv2zorqx5 ration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plaxvv :* 2xp(j-.zbqo5 m uxt. bkfrjm2/ne is flying?

  A pilot makes an outside vertical loop (in which the center of the loop whk(9 b h4f8qnp7n0:otb3w op(0vdv gis beneath him) of radius 3200 m. At the top of his loop he is pushin(v4wf7q3vh kgbd: 0p t h(wb onp0o98ng down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is xnh( uq1roy8 -8lj) bgabout seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pullingol(8uj -ry)1xgqn h8 b 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 hori+:9o mz8-h*qvgfu- 3qdfeki .vvz tn*zontal 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 eavfq3gk+e:*m in- 9f8v*q-t u .odzvhzch road surface.)

  A car is negotiating krsc w vv/8.)5,o nuhia flat curve of radius 50 m with a speed of 20 m/s. The centripetal forceov.hi) 8/csr,w5 vkun provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat 1p83boh wt-j ;bsne0:zxem+uqin3i / curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the tbp ij8zq :1uie s0 onx-;tn 3w3/me+hburn?

  A car is moving with a constant speed v aro:usm bs g-;x/dxmdrv i(rd,(g8zeq,7 und a level curve. The coefficient of friction between the tires and the road is 0.40. -urged i d8:vms, g7(s;(b d,x/ mqzrx What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is requi(p h2cl fpw h;f6p8z+ ,lvj3vjred for an Olympic bobsled to negotiate a 100h2c6(lpj p3 ;vpw l ,v+fjf8hz-m radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ru: reu2ait;w5uj/ m x*ln is banked at a $45^{\circ}$ 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 rade eh+ ;kkh:;*2tjrp uzius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked (lkckk 7qq,)s*g7kbm 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 unifvh4f2ixxhj -+ad)( zqy :.v ahormly in a horizontal circle of radius 0.500 xvh+2f(v)-i.h q hxaad4 :jzy
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 accelerates at a unifo2 ncyddft.(m* rm rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in nume* dmt(.dy fnc2rical value in 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 consists of a proton of mass ol :.lxx: d0ao0 8qskd$1.67 \times 10^{-27} \; kg$ 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 force on a 70/wz; kova8rg )p.ls5j-kg person standing on the Earth, due to the Moon? The mass of the8sl)go;r.v jp5 zwak/ Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational at mrkdg/p7((xy(m8 u l)zlhmk(tractive force between two masses is F. If the masses are movedl( (r y(g lz/uxmk(78)mmphdk to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth9ws 9sebx6 1v(q3j qah toward the Sun, at what distance from the Earth will the gravitation91qs 6(vehjwxsqb a93 al 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 Moon zc.r j g)7)..hb:lmoab 4tb5 grnsk/o 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 for a "space-walk"i67n* 4el g z6m3-f7jvwpdpcu at a distance above the Earth equal to the radius of the Earth. What is her acceleration d3m dp*cgjzi 7 eu646vln-p7fwue to gravity?

  The radius of the Earth is R. At what distance abv j9ozvun)f- 9u:,zblove the Earth's surface will the acceleration of g9n9fou:zlu)b,zvj -vravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 f)wgwx: s)29t bwjkk 7ldkg )1times the radius of Mars. The acceleration of gravity of the satfg9 dkt) kg7j1kw: )lb2) wwsxellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the aq r z4akn7,sr5ymn10e cceleration of gravityq ynm,ka7e41zsnr5 r0 is $32 \; m/s^2$. 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 Eartft qj8e4h/6 uth has radius r. If the object is raised to a height of 3r above the Earth's surfac qe6t f/u48tjhe, what is its weight?

  By how many newtons does the weight of a 100-ki*amvr(py33c; m y55 0 zpzyysg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth53ycy p;i msz50va*rmzpyy 3( is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r xg7y)/butu .gabove the Earth's surface. What is the satelu .)u yg7/xbgtlite's weight?

  A spherically symmetric planet has four times the Earth's mass and ty-he 3hvl0kbc mfolfhu :22r 1ia;6f/wice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth uovaffrc mehi/20-fy 21l6:lh; kb3h, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moolu c( i2gne5usxmqisg; ;03u)n, Earth, and Sun all lie on the same line, with the Earth between the Moon and thu0ic(5i ;u;)sxl2gq n emu sg3e Sun. 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 the Moonzce;mx4p n 8k/.
(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 the Earthx8 ad)odh* zx9 t- ni)tq :s(zja8k8cw (i.e., it just skims the surface of k-8 h9:)*c az djit)dqo t8wxz(xs8nathe Earth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about thoh t(88pwuwyi.tme t: (2pi 2ke Earth (i.e., it just skims the surface of the Earth). How long does it take to make one rev pi t(i2etpt.yhw82uo8k :(wmolution 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 Eartkzae. ly7 gj44l0: yxoh. It is observed to have a periodogll4e.x y7y0k j4az : of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiterxam5c/m e1r; n, 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 Jupiter orbits the planet with l jihg61bk ;a8izs-a*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 nearly circula si;d5 /2sg*ucxa d(uwr orbits. Moon A has orbital radius r, and moon B has orbital radi* dusags (;dw xc/u5i2us 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i jtj5 zo0cf 55klm a80 xq4ujub/64diqs $7.78 \times 10^{11} \; m$ 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 once. Wha v:nc*s-)f7xwy m4(.on d,fl (hrn mpdt is the average distance from Jupiter to the Sun? (The distance from the Earth to the Suy7now-nd)x md(mf f :4r.hplnc, *sv(n is $1.5 \times 10^{11} \; m$.)