Is it possible for an object moving with a constant s/6ir*e rd0nflofj 6g (peed to accelerate? Explain.ni ef(*gr/ 60dljor6f

  Consider a particle moving with constan;zxmtjy gfqi +t*.d slu((h) ;t speed such that its acceleration of constant magnitude is always perpendicular l(g); yhs(*ztd;tj ixf.m+ quto its velocity.

  An object moves in a circular path at a constant speed. Compare the7c3qn5rq/cs c direction of the object's velocity and acceleration vq 735cc/ sqcnrectors.

  When an object experiences uniform circular motion, the dirz; )qvn1u60tuwj c v2rection of the acceleratinj;)zvqtv0rw 16 cu u2on is

  Consider a particle moving with constant splunmifwz-2d-y53 ib 4eed such that its acceleration of constant magnitude is always perpendicular to its v45ynizl -u2bwdm fi- 3elocity.

  What type of acceleration doerq7 :a (+liulus an object moving with constant speed in a circular +7lli(qar:u upath experience?

  What force is needed to make an object move in a cv4nwz- l5sbil1+2-cn- m 23uwa u uptbircle?

  When an object experiences uniform circular motion, the direction ofn8a/te0- h)a2f fb eie the net force b0e t2/ef)e8i nahaf- is

  A roller coaster car is on a track that forms a circular l : v fz03:ouvuutyzsecx-n ,(*oop in the 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 point? *o-yt 3x v u,zcnf:e(u0:vuzs

  A roller coaster car (muv /uhutjl+0egncor67: p, ,eass = 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 loop, what is the minimum value for its c,/u:l ep0hng u ,or+u t6j7evspeed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc 9rp9kl2o+ 3rvysa8fg until it is going straight up. Just as the plane is at its lowest point, the force on him a+ s3kv y9pr gl89orf2is

  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 radiu vz lnqy4./d,wvhxs+7q g ib5;s $r$ 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 j v72f6 fsn:4v) ufpvdv. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second ti4f6u f27vpvfds)v nj :me, compared to the first time?

  A car goes around a curve l/45pro/*e354,j6hh y gdu6umrenxt 2zeuqa of radius r at a constant speed v. Then it goes around a curve of radius 2r 2neq34uz,//t l4 mdhruu j56epxog5e6hya r* at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked cur2 j5ic +b vlwq0xiwtf-*0p r4rve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the ct0w+r2-r4 liji5c xpq0v fwb*urve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curvef off kg*/1o 8i-r 9bjas+o:pes on a 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 smaller radi8b-ofspi*: ao frgeko19/ f j+us curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turv(9 j60dix; k: xiecihn on the Olympic bobsled track is not constant, but increases upward from the horizontal.i v(x jdk09eh:icxi;6 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 moving around3, 74)ewatql 4)afq hsca* rnx a circular path to have both centripetal and ew a l)a4*nxha)7r,cf34sqq t tangential acceleration?

  The gravitational force between two objects is prop2 13o0wx cxsty+)ningc2xf a5ortional to

  The gravitational force bef+)j m*v u-zez4y9(ne 8sh rnxtween two objects is inversely proportional to

  Two objects attract each other grauqml1 j8u x q;vpcnmwm igte k5246:c41-ap u0vitationally. If the distance between their centers is cut in half, the gr x6jl 2m4ta1:nq41p8gq5 ecpu-; vkmmw0c uui avitational force

  Two objects, with masses :/n60cjcd c ge$m_{1}$ 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 massesn70v,9cnu z:f e-:*xo(7flo llgcnno $m_{1}$ 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 gravit ;lg:twqt wf+mg1 /5w1x(ghgtation.

  Compared to its mass on the Eartgq+2o z(pt7)y :kd or pz5)zrwlm:/xq h, the mass of an object on the Moon is

  The acceleration of graviwpy t r-i2ev.;ty on the Moon is one-sixth what it is on Earth. An obje.ir-e2vy t;p wct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the h5hf*9 4ns kvhrocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond tiufgi-mf/ 4f /ly 0(o6djawe 56( drwghe pull of Earth's gravity6 4/6egiwjf5da((fgyu- wfl mordi0/?

  Suppose a satellite were orbiting the Earth just above the surface. What i+z9)im+,kr 5u jp rau:gvfzlhm )y//is its centripetal acceler9fh/+mk+ z gi)y l :r,uvm)za/i5j pruation?

  A hypothetical planet has a mass of half that of the Earth and a radius of twiclq/mbj 60zzw *e that of the Earth. What is the a* wzlzbqj6m/0 cceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of q/ +) g1 ho yop7ql1ucxdy/jp4da3gx6gravity on the Moon is one-sixth what it is on Earth. The radius of the Moo ghg d6y/1yp/uqo7l 3c1xoj4qdxap) + n is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface grav; p)vay t ge*dn+ -p2tc6)cumcity, but planet B has twice the radius of planet A. If planet A has mat+u)tc *ym-6vcadnp; )p2 gecss m, what is the mass of planet B?

  Two planets have the same surface gravity, 7n .tuo.(zn:fcsc3w wc :g 3zdbut planet B has twice the mass of pladwz .tncuf o3 gz7sn wc::3(c.net A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a 3aor ju3 5hsvb, m*2qgcircular orbit (radius r) about a spherical planet (mass M). Which expression 523jmq h*vsr gob,a3ugives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotateodl3pnjiyv :) /f; zf 5z:lnx-s in the same orbit. Compare the )j;3dip5l/ z: ffvxo y lnzn-:two satellite's speeds.

  A person is standing on a scale in an elevator accebya0gb1: o+ m-9(tfednaqp 1lky c.m,lerating downward. Compare the reading on the scale to the person's true weighgp by- t01 mkay(o 1b9flaq:cn.+e ,dmt.

  Who was the first person to reali-9ww8jl f v(sue8bzv ii 7(*jxze that the planets move in elliptical paths around the S8xi we(b j7z*vw9is( ul8f-jv un?

  The speed of Halley's Comet, while traveling in its elliptical orbit a,+ugf (inoh)ky7qf6 i y+m+auround the Sun, +f+i)o7 kn(gyfqua+hm6 u, yi

  Let the average orbital radius of a planet be R. Let the orbital 7tb htr nlhbm,c9v,bg+ 0nztcv,20 6aperiod be T. What qu7,ccb,0tnrav9 bzh+hn l26 0tvg mt,bantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galagct*i u ort/,f,5 ait*t04 y:la ap3lcxy Andromeda, with the same 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 t gu f4* *ol/,a30:a5r ta tlic,iptycthe Earth's orbital period?

  The average distance from the Ea3:zaicb1wq b vb:t(q2rth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average d:b(bc iq3abqtz 1v2w:istance from the Sun?

State Kepler's laws. a(lw7upnd;z*tw,re (

  List the four fundamental fol- (nqp5)ye zorces in nature.

  An object moves with a constant speed of 30 m/s on a cztm.w(83 q chzircular track of radius 150 8q3 mtzch.z(w m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What ig2 tcgtwnluj/a+(ybu0l7(. qs the maximum speed around a curve with twice the radius? (Assume all other fa tngtc/ql(+g(ub.lu y7w 20jactors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicyc1y0:tc(atjyber8v zqk74i, mi u . *awle wheel of diameter 70 cm when the bike is movary(kz .v4u 01cm7jiq 8eabt iw:yt,*ing 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s ibucio *0 2j/ld tcig/5s located 0.200 m from the axis. What is to j/ c5ii*gdut 0lbc2/he centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station oforw*ztay/-0 o.r9w6r 5kxd5 nuhs) pw radius 1000 m rotate to produce an artificir6ysax w k0ndo*)-o/rtu55 rw9w z.phal gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aroun5ek430bm c5gau)5ee m4i+ tt*ubx p xpd a 13.7 m radius turn at 96.5 km/h. What is the centripetal force 3emcet5 mxpbet5a4g*k+4xb 5pu i)u0on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system9:,xo0 d4/xjnsmm rvjl b:j*r is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the striml4sxx, d09v/jmb:jj r :n* orng is not to break?

  A stone, of mass m, is attached to a stro ( uxcg7f.jxh ;a eh0iv;b6f,bco 2a:bng string and whirled in a vertical circle of radius r. At the exa,cx;bb f0ha.6 : 2og( cvui7bxfahje ;ct 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 stronyw rt8s5 :*)g3lu xkzhg string and whirled in a vertical circle of radius r. 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 ru h8s5x)*w: yklzgt3 point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g ylzn22cr.t8 swhen pulling out of the dive. What is tt8c22zyn .slr he radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside verticierh/vt- zyj+3l qo6+k86wck al loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his n-j3/h6+v ckek6 oq ty8l+rizwormal weight. How fast is he going?

  The maximum force a pilot can stand7 i, )l aqd5q*oulml e4 ye363psz)dtd is about seven times his weight. What is the minimum radius of curvature thatt5le6)q d u)*deazl7i3os, 4l mdq py3 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 horizontal curve with thek qzd1d2 de;s- tires on the verge of slipping. How fds-k dzdq;21east 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.)

  A car is negotiating a flat curve of radius 50 m with a speed ofp3e2 9.ozr tf0c ffm.o 20 m/s. The centripetal force provided by fric90mft orp3.cfo z f2.etion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a speebm kzsf4x-op: dvl4 lu2pz 7-3d of 14 m/s. What must be the minimum coeffici4k plv m x4z dl-fb3z:-27uospent of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The z(2vys yx,e ju +dma;ua0ed3-coefficient of friction between the tires and the road is 0.40. What ,e m2zuu(jsae ya ;d 3vy0-d+xis the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required formavybnk kkx)1v9 e98( an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignv) mv x9 81kakkb9(enyore friction.)

  A horizontal curve onp2 bs+c/:e s)wq 3ng h::mowaf a bobsled run 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 radius 100 o67rmko0mk))tvam ;)3ulg ni m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked d awx96ju6pr:(2gaaiat $45^{\circ}$. 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 u7pa w. 32jiufrniformly in a horizontal circle of raip 7r.j 3ufw2adius 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, c 3)3vtpr e/xia race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a c/rivecx p3)t3ircular track of radius 500 m. (only fill in numerical 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 consismh qd*hyn5. 21/gjsucts 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 force on a 70-k6 7v;ju;ikglm g person standing on the Earth, due to the Mookvug7im j;l;6 n? The mass of the Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two mass;j yx7sx 0x3j7o)xmdkes is F. If the masses are moved to half of their initial distance, what is the ymo ds7x7 0kx;3xjx)j gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, 2e ca5)9enrtrat what distance from the Earth will the gravitational forces due to the Sun and the Earth c95c en)r2tra eancel?
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 islffk),ofan 4 tk6nu 49 $7.4 \times 10^{22} \; kg$ 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" at a distance above the Earth equal to7 dwpbfboi m)*mv junv:62v1m3:fv q* the radius of the Earth. What is her acceleration due tojd:o*i2 m:fuv*7 mbqvnb vw 3m6pf1)v gravity?

  The radius of the Earth is R. At what distance above the Earth's surface willej.+b ns/qglx v0*hi7 the acceleration of gravity be.b7/+*si 0vh ngx ljeq $4.9 \; m/s^2$?

  A satellite encircles Mars7d0+d1 qqdfe x at a distance above its surface equal to 3 times the radius of Mars10dqxedf +q7d . The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some e1sqd es*. f/ho1r -tgenvsa h9w;e +/planet's center, the acceleration of gravity ish*avw;/ -hr1.eq1fsn/see so +t 9egd $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the su9i9d;v: 4bw0a gtby 2wyrn5k. ywxm;trface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is 59wnv ab4w;yd x. ; 0tkm2yg9i:yb wrtits weight?

  By how many newtons does the weight of a 100-kk u/iu, 2f5iinqpr-() mtuje 5g person change when he goes from sea level to an altitude of 5000 i)uejnfu5 iq/rm- i 2(,uk5ptm? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above the E)ma d5gj(r/i varth's surfavajg 5 )dm/(irce. What is the satellite's weight?

  A spherically symmetric planet h.0fyv vwu( 2sp5abub09/qx0obf t 6qk as four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surfqxk 6po0y qsf 09bu 05ua 2vw(tfbv.b/ace of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all -2cx . -nnt6bwvpz hp3:jj1pr lie on the same line, with the Earth between the Moon and the Sun. 63p--wcj zpnt.1:rb2j pxhvn 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 tran 2v/gdr4)::g-p n00p+ qjiacf kwnpsg sported to the 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 the Earth (i.e., it ;hm o,fyzo3 z5cb4+jw just skims the surf,ohfwz;4c y5b+oz m3jace of the 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 the Earth (i.e., it jueik;jsgx 93b4*-xyq f ye,;xj st skims the surface of the Earth). How lo-b gjkq;i9xfxs,eeyx4y 3*;jng 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 s .8u:zfm+z9v wet ai5fj-cn6 durface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius o-we : dcv8tf65m f nz.z9auji+f the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has r)nvt*hg0 3g dan 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 Jzpcrq 5,ie bym .atcgkj* ;,+;upiter 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 nearly circular orbits. Moon A has orbital 4 s8wza1) kxyy8es.de radius r, and moon B ha84xz8.sk1 ewdy ae )yss orbital 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 isaxbkc(e1p71o imk7u ) $7.78 \times 10^{11} \; m$ 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 ye(w r-0xl d8evwars to orbit the Sun once. What is the average distance from Jupiter to the Suwl 0-8d xver(wn? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)