Is it possible for an object moving with a constant speed to acc/f9+q xi zkj:dq io7xj5rch w-mnb7;d);d9 bpelerate? Explaij cb;b+579 7 kd/fxnhwjr) qdp ;zo:x9-dmiiqn.

  Consider a particle moving wg sqe3m9-z om6h* (pyiith constant speed such that its acceleration of constant magnitude is always perpendiculg*mm69o( z-hp3q yeisar to its velocity.

  An object moves in a circular*, -08epvyf kl jaze j;.+oqu 5)wjwce path at a constant speed. Compare the direction of cp ;ef8,au5yk-ejeqz loj) .*wwv+0j the object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the do6;izgv/ax,- uxi hg 3x/p4emirection of the accelerati igz h,xi x6u /e-x/po3g4;mvaon is

  Consider a particle moving with constant speed such tha k 9yy; ujw-ya)gj2v8;ww l)cat its acceleration of constant magnitude is alwajywkwyy;)9;cu j)a l -8 gv2ways perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed 77xwlo x 9xb5kdir4ze v -.0fbin a circular path experiencez4l50 w 9xoxefvbx-r d7k bi.7?

  What force is needed to make an object m3n z8hy g*2kb,n.k bfsove in a circle?

  When an object experiences uniform circular motion, the direction qz/0ga-bi-2uy bd ch;of the net force ic2 yi-auh zgqbd;0 b/-s

  A roller coaster car is on a track that : cyt v71)hi q dzya6s3+m77njxsv1frforms a circular loop 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 its7qv7n v1+:fjxrh371zdsa m) ys y it6c centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track ths;)vufz- 2 rfk4lwg /q t4/pnzat 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 speed at that poin;k q/lz/2ngru)f 4-4zpsv wf tt?

  A pilot executes a vertical ditii ;y3skacme yc+-31i nac85ve then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on hiycca ci;ymn35+e3aski8-it 1m 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 h9x fhnkq947q curve of 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. Then it goes arou1ej-h;mt3l q vcyj56mbzat 9pl3dv1* nd the same curve at half of the original speed. What is the centripetal force on the car as it goes around the cu*; b m3zctlv3l5eq1ah j 6dpv1t9m-j yrve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant1tgqgx1g u,3nmw3t w 9 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 around the second curve, comgx 9wg3q1,t3 twg1numpared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If xi6 d4;gq9da0:bc mnfhpc(o7,n tmc 6the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude tof,c ( 7t nc0d d:mq x4mio6n9;ahc6gpb

  Two horizontal curves on a bobsled run are banked at the same angle, but((o2rhpq db 2a+hk m2w one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius cb2m22a + prow(dqkhh( urve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobs+f3iaf-f(th: esn1 uwled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," thentaw nfeuh- i(3 f1f:s+ go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circul9 akem)u0 4srqa(p+q par path to have both centripetal and tang s9prqqm4p( 0aue)ak +ential acceleration?

  The gravitational force between two objectsy3eu:0ixa4a)01le r,it )a cx+oea mx is proportional to

  The gravitational force between t58 jqv my.h*xgwo objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance betwe+ 1e )f6fa1yrf/qmgzten their centers is cut in half, the g1ea1/ygt6f+ rf)qzm fravitational force

  Two objects, with ma,ymyad*//mo h sses $m_{1}$ 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 masses h*p8pvb mi: ( 4s6filkw 37sdn$m_{1}$ 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;7 *do ox:vr: ej69bnt;p iyo+j9sbrt universal gravitation.

  Compared to its mass on the Earth, the mass of an object o7lwny,.( z qhjht s,/dn the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earthgtwja 1sy . 4oswul2pk2 f88t0. An object of massjsywt8 gtku2.lsf1a02o8p 4 w
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rozo,a.pgju.5+z03xwsfba - bmcket's weight

  A spaceship is traveling to the Moon. At w f+8s.mu :bm89igmkaa hat point is it beyond the pull of Ear9i m+8 gfs.auak:bm8mth's gravity?

  Suppose a satellite were orbiting the Earth just abw voh) 7mh7e(4vslgid7)a( v gove the surface. What is its centripetal accelerago7e(vl)7 v ismda4v ()hhg7 wtion?

  A hypothetical planet has a mass of half that of the Eec8kf0 fxu2jq.so fqd )6w0n.arth and a radius of twice that of the Eartnq f)e0s0. wf kjq6odf. c82xuh. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-cj p tmc5.vqg*lx7.)k sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compar p km*)gtc .7xcvqj.l5ed to the Earth's?

  Two planets have the samex+b:pdont3m w2p jx*; surface gravity, but planet B has twice the radius of planet A. If planet A w: 3pot 2+nxpxj bd;*mhas mass m, what is the mass of planet B?

  Two planets have the 9e 6huj3yun:4ytbh t:+eu;lu same surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planeu9:6jlet:yun3y4h+e u;u tbh t B?

  Consider a small satellite moving in a circular orbifkkj u *pl.s/w13uy/ gt (radius r) about a spherical planet (mass M). Whic.u / 1u* jgp3l/kskywfh expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbic fi-c dhm*;qd0 ;wee*v5/gs bt. Compare the two sa g*0s eeh;5vd;cwd-i mqb/fc*tellite's speeds.

  A person is standing on a scale in an elevator accelerating dp2;t ky 1icw6uownward. Compare the reading on the scale to the persontciy1 u;6wk2p's true weight.

  Who was the first person to realize that the planets move in ellipztmw n;ns+s1 s+66ajftical paths around the S1naw;s+6 sjmz +ns6 tfun?

  The speed of Halley's Comet, while traveling in its el57pqg+b+ nxc aliptical orbit around the Sunabng p ++5cx7q,

  Let the average orbital radius of a planet be r.m2m u2fb chn3i pcsuf hxz-;9//b:iR. Let the orbital period be T. What quantity r m.fhfis9/npi2x- c2um;b/hb3zu:c is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxu0ivnd4w* t+r,zw(yf3xeq b8 lr2 g 5uy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our f28wu3*+ urdt ,yv4w n b0r(5g lizxeqSun, 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 oy)ytm4b; -tv1 d8x fmxne "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from xt1; tymd bm4v)xf- y8the Sun?

State Kepler's laws.19 m(qs(1jro7v wjoxh

  List the four fundamental 3z/*n3zmzeq, w8l zeu+ e6zgela+/are *ku2xforces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radig4khsm0 xgzyg 2bs 0z58mw: 5nus 150 m. What is the acceleration of the objzysxs0 m hk b:wg84n5ggmz 052ect?

  The maximum speed around a level curve is 30.0 km/h. What is the mahz mj*c-)ugzvjb;)6z ximum speed around a curve with twice the radius? (Assume all * - )m)hjzg;cju 6bvzzother factors remain unchanged.)

  What is the centripetal t7d3 gyq+xkx2acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bik x7dg2qky3t +xe is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. b ak:p,d:holc7s 8g*jmxnq6 3 What is the centripetal acceleratioj8c7o pkh:q bs:,6xlam3 dng *n?

  How many revolutions per minute mustp -im5-q ztwgud1 (+tt a circular, rotating space station of radius 1000 m rotat+qw- m(tg 1z5 tu-dtpie 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 atuyyclffr yrr4 t+ 46)* 96.5 km/h. What is the centripey4 fr6y+ lutr)rycf*4tal force on the motorcycle?

  A 0.50-kg mass is attachi jvs3ik (cr mx9:8mgtp/u:3yed to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 35033(pvjsimurg/ y8m9c:k :i x t 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 in a ve k2al/ukki,;wrtical circle of radius r. At the exact top of; ka,2lwukk/i 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 t/j8ct:x(b a)qigrwj i g fvqtj+/1*z3 o a strong 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 point is given byq 8 :3 cwxbfaj)zj+*ggvt(i rtq//j i1

  A jet plane flying 600 m/s exper9huq,qkg kb53gb g v-5iences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which thg3kv 59-,hq kq5ub gbge plane is flying?

  A pilot makes an outside vertical loop (in which the center of 04.juikq 7*(llkmc vhthe 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 hhil*mqjv047.kk( c ulis normal weight. How fast is he going?

  The maximum force a pryqhz.h bf4ctlb2 ef c*)r1b9m2l n, b-::afnilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can toleratb2tb nf.)1eq*f2zmhhnb b9y,f : cr ac l:rl4-e at a speed of 250 m/s?

  A car traveling 20 m/s roemg6 x+ (dk-ve(8b2s aqie 9ynunds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the nmged 9yax2 e-+(q(v is68kbesame coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50m7. 6lystl (ta m with a speed of 20 m/s. The centripetal force provided m7s(y atlt.6l by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radi+mmi4(5s2ygq9,ar ft ;wzxsx 6- m ytius 50 m at a speed of 14 m/s. What must be the minimum coefficieny+a6my x, 4q rs sgxitfmz;-t2 iwm59(t of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speeqwxy )sln k/+-88o cuut2 w;dud v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if th/ uo+8;nw2-uq l 8y )twudsxkce car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 1y,/lm e0i(zqqgrc95b:gh yhgn) l6 q400-m radius turn at 35 m/s0(: b gzimggy 9 c4hqq5/eh,qy6nl)lr without skidding? (Ignore friction.)

  A horizontal curve on a bobsled :x 6r-buri1zsrun 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 m, banked at an angle4il58ime 8r;vabgak2 of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedlztqd aq,u v ez+:e;t6g(7s c)hs-s7p 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 uniformly in a horizoik0t fgx o1.x*ntal circle of radius 0.50xi0xo gt*1k.f0
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 uniform rat7; nakq6s9 q1l xmf9hme to a spefx;qlm 6m 9sakq1h n79ed of 45 m/s in 15 s, moving on a circular 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 consists d h-5fm5nxfk2of 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-kg lozjk(q j8m-.t,. d xfperson standing on the Earth, due to the Mooj.,kqz (-fltx8j.d o mn? 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 forjv7l d xx5w;m1ce between two masses is F. If the masses are moved to half of their initial distance, what is the g;m5 7x vlwjx1dravitational attractive force?

  For a spacecraft going fro;0u2q-j r2grhlz7riehu8 l*q m the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth care ; hlu2rqzg7 -rq*h280 ljuincel?
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 Moonv d2.a)hjih j) 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" at a distance above the Earth ezklet( o20(z wqual to the radius of the Earth. What is her acceleratio z((o z2k0elwtn due to gravity?

  The radius of the Earth is R. At what un(4h2 .tifxl distance above the Earth's surface will t2uith x.4lf (nhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars ats+2n )l rptwql; xoh+0 a distance above its surface equal to 3 times the radius of Mars. The acceleration ofrhp n wt;0l+qo)x l2s+ 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 planet's center, the acceleration of a1 m.j is9p+oogravity is1 .+ a9sipmooj $32 \; m/s^2$. 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. bg+hpw. tt /ep6z: 3h ul)9*xecmw4dc The Earth has radius r. If the object is raised to a height of 3r abxhe3t9pbu+d6w4l.eg:pc cht)w /mz*ove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person g ytnua4n 3:n:t*: wzhchange when he goes from sea level to hun4tg*w:y3: tz :nna an altitude of 5000 m? (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 Eax(h( ( ze32eputd-c-df-jg kogj7 g4rrth's surfo fxkdt ehj- -4 dgg((pg3cj2zr(-e7uace. What is the satellite's weight?

  A spherically symmetric planen .z2h9kohlvp08 i bb+rn0h f6t has four times the Earth's mass and twice its radiunr6f80vkohpl920i bbh+h z .n s. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all y7 bd47;wz),jjfyz b ulie on the same line, with the Earth between the Moon );bjd,byuy7j z 47wzfand the 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 tobf*.mre0e i y, 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 aboa/, ozqh l*x)g)s8 n42w tjlwfut the Earth (i.e., it just skims the surface of the ojxszl q wnw/ h4tfa82,*)g )lEarth). 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 1 *k b-8ouaslmEarth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean1 u8bslm aok*- 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.x2 po k.ca:t9e It is observed to have a period of 89 9p kca:.x teo2min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter)- 4n5uac6x9ttozv 1t )kc5x: ra xnhp, 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 5;ol ah/tcne x9/ hc1mplanet 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 circul,90vd l6dfeanu-3 zioar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r.e d3u96fv- alo,0i nzd Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is1em1jpx8zy-c: p u pp6 $7.78 \times 10^{11} \; m$ 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 1r8aavsmjj -ht3h, 8(bu h7q4uz.+ trq2 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the h -m.4(t, zvj ju qhah7q +r838artbsuSun is $1.5 \times 10^{11} \; m$.)