Is it possible for an object moving with a constant speed to accelerawly* gu rn+a7z: ey.a)no8; xfte? Explainweyz: ly+a 8onfagr ;unx*).7.

  Consider a particle moving with constant speed such that its acceleration of conlr s4 :tcyc5p musw,1;stant ts; cw:uc5lmsyp1, 4rmagnitude is always perpendicular to its velocity.

  An object moves in a i;u f32)g.be6hckcbtcircular path at a constant speed. Compare the direction of the object's velocity an3hu ;)cb ke.2bcgi tf6d acceleration vectors.

  When an object experiences uniform circular motioo7h66ev*z4u8 j ucubd n, the direction of the acceleration is67v4 z8uocubhu6dej*

  Consider a particle moving with constant speed such that its acceleratiobei0i 8,gnv7qn of constant magnitude is always perpendiculaeg7qinbv,8 i0 r to its velocity.

  What type of acceleration does an object moving with constant speed in a ci7imi7(sessdqoq-dtr + -5u4zrculai-smq z e-4 o+r7q(5tsudi s7dr path experience?

  What force is needed to mak(haoz6f*.fl(s j;brp e an object move in a circle?

  When an object experiences uniform circular motion, ts--pi4w/wc f s7; jowshe direction of the net force 7ow;/c is4 fsj -s-wwpis

  A roller coaster car is on a track that forms a cizfe6:.c/rllmgf 1 g+zb xn)+lrcular 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 its centripetal +1nl6 r: femzbglgf/x.)+c lz acceleration at this point?

  A roller coaster car (maspu4 c xj.2hj,( owvh h(y.ske(s = 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 speed h4(k.wjcs hyo(jvh.2e( uxp,at that point?

  A pilot executes a vertical dive then follows a semi-circular arc unoqlg tm0k.ot(yt t*2(til it is going straight up. Just as the plane is at its lowest po2 mto *tg0oq(t ykl(.tint, 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 r) jfdzdd9v+ rkc g3e+w y*8)vjadius $r$ 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 itpstq;jm)x4n zepv 5 t9l*6t/ t goes around the same curve at half of the original speed. What is the centripetal force on the car as it gvj/t4*q96 5sp t;x ntl tez)mpoes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goes ip7ll qkajz2-dny7 /rt jiogp :0j,)8around a curve of radilj/ 7pit7ld ,kqz jpya)no2r:gj- 80 ius 2r 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 curve of radius r wirw/y4*qwl9 lb/q m1f )s:xdwx p) *kvsth speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal for1*p qr kssql wdxv4 x9wm/ /)ylfw:)*bce on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angled:)zigcbb tug/bz j 0 7+y;pr5, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run)j) bzzbp;5g0y7g/ utbdi+c: r 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 ii;c*y bss35 anrm -d9qs not constant, but increases upward from the hsy-5;d*cbr q3 sanmi9 orizontal. 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 around a circsija3qz7j uu -* nyw;) 5kkzg.ular path to have both centripetal and tang.-qkz )u jw7 ki;*anz3j5syugential acceleration?

  The gravitational force between 3/+p 0znyr fnx-aez wa5tgz* o;;ys 4ytwo objects is proportional to

  The gravitational force between two objects is inversely proportional t( vm e1 xngtb5zf ahwyk4+65-ho

  Two objects attract each other gravitazz2;9odn hpt4jb,nwth6 . op,tionally. If the distance between their centers is cut in half, the gravitatioht. h9 ;wpzpo nzn,4 jt26ob,dnal force

  Two objects, with masses gdafaal1c5xs41rzy5(h w ;s; $m_{1}$ 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 1zxml o4:b*jf$m_{1}$ 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 gravitation.q71s 1 ddzvmc6

  Compared to its mass on the Earth, the mass of an objf:dvr0 .e/qib q+ )gtsect on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Ear4pp2q f1n m9yh pav/l8th. An ob9mfn l/q4pa81v p2hypject 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 rocket's weight k+;q x t(x:uq g1s)1cslh:xrr

  A spaceship is traveling to the Moon. At what point is it beyond the pullr/ se3c0 mp0ju;l r6vx of Earth's 0x6sjl p/;3m 0ecuvrrgravity?

  Suppose a satellite were orbiting the Earth y)wbhp i( v*qrh +;dmp*n f5k*just above the surface. What is its centripetal acce +*5v)py*pw(i; m kd* nqhfrbhleration?

  A hypothetical planet has a mass of halfl c7o 6+yl-glzy (g6sa that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms ofyc-og6z s+ 6gll(l7 ya g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth.hzn,b1-+s 6v tf1 bgjm The radius of the Moon is one-fourth that of the Ea t,6+mbf-s1zng jh1 vbrth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice 8q9ozn bj 2+clzfqmv0a43c k2the radius of planet A. If planet A has mass m, whatc+zq qc80o2lmkab234 njv 9zf is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of pekd hh u(7 t9)s3v u3b-hvw: n8ffryq/lanet A. If planet A has radius r, whwu7 )vbhhf :y9trn8eq- dk vs/(3u3fhat is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r)f34jrz. im )rh about a spherical planm4 hr3). zfrjiet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in9(cc)h hi4tp u the same orbit. Compare thhcu)c(i9th4p e two satellite's speeds.

  A person is standing on a scale in an elevator accelerating dow.oqiao , 1s,ighg:*oqnward. Compare the reading on thegs o oq a,oi:ghq1*.i, scale to the person's true weight.

  Who was the first person to realiziqg)v) m04dw *5xzprj e that the planets move in elliptical paths around the S5 i xw4qj*0rzv g))pmdun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around4y41yoh- skv49xqz dy o9org* the Ssoy ky4qoo*19xdzy 49gr v h-4un,

  Let the average orbital radius of a planet be R. Let the orbital period be *:-i+regptcdh2b* 9;gnlx ndT. What quantity t- bldn2xd:*c ;9hgr *g pnie+is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witkp2 zd+s: u5qosd) 6xph the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what q5sux 2o6dpzps:)k+ dwill the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Eart)d6+* c7vg qw(zbnlekh to the Sun is defined as one "astronomical unit" (AU). An asteroid ) 6nb*g dq+wzlckv e7(orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.x0urb)h 1w*h/efysf t2cp(: w

  List the four fundamental n+bfy 525ug0cxttw* dforces in nature.

  An object moves with a constant spjn pd d +) kasql)o.4v2sjhjm3w-. g.eeed of 30 m/s on a circular track of radius 150 m. What is the acceleration ofs)wq o a-pj ge.s+mhn.4jkd2 v3l.)jd the object?

  The maximum speed around a level curve is 30.0 km/h. vgd,v /8yiak8e 4,ush What is the maximum speed around a curve with twice the radius? (, ey8sv8h a/k,vugi d4Assume all other factors remain unchanged.)

  What is the centripetal acch puy,br y4f( jzz;(i).w/ mr:oc*ggveleration of a point on the perimeter of a bicycle wheel of dia.z:()p/r*r ybgf ohg(zjiywu ;m4,v cmeter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ax( w-aqca*om5z is. What is the centripetal aa-5zw oam(q c*cceleration?

  How many revolutions per minute mcy:-zrjy) em. ust a circular, rotating space station of radius 1000 m rotate to pro- zem):j ry.ycduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a ma,j;:yt+gqyv f2r9 hwxci/k*rss of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal qhr:jy,*tk+9rv xigc/ 2 y wf;force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirleds -)r,ykrzggv)zfw6x9p 3 + ep in a p f93gse,x +z)g)rvrp 6wyk z-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 string is not to break?

  A stone, of mass m, is 2 4joby9tefj5ut8mwn8s,q 6r attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the pe9umtnby8o rwt245j s 6,8q fjath 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 whir3pvb:p4a6ql:p cq8 huled in a vertical circle of radius r. At the exact bottom of the path the tension 3q4 pqb6plpha8:: v cuin 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 acceleration of 4gg6p bt5p*w-8eh) x mcm when pulling out of the dive. What is the radius of curvature of the loop in which the plane-8em5bxp 6* t hgmw)cp is flying?

  A pilot makes an outside vertical loop (in which th xb6ki.)h uip/e 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 normal weight. How fast 6kx /h)u.ibpi is he going?

  The maximum force a pilot can stand is about seven t1,:o,,aih7zinotd ),nx p q jpimes his weight. What is the minimum radius of curvature ta dpq)ioxot:7i,,hz ,,jpn n1 hat 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 wiv+ dxri)ub14f rcm x .ve8nt8-6wpx8 uth 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 tirv.4ev f8m+dwu)8xbr6urn1t pc i x8-x es and each road surface.)

  A car is negotiating a flat curve of radius 50 m wit2m)-ogp ;hvlih a speed of 20 m/s. The centripetal force prp- g; oilvhm)2ovided by friction 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 nv 5dya0v-6-uppi3; ahx mu+jat 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 t a6ypd +nuh0- uj-xm;3i5vpvaurn?

  A car is moving with a constant speed v around a level curvbbmii4qe uf9 mx- 8nx/t n8n16e. The coefficient of friction between the tires and the road i u8i9f-m64n xbn q1n/ 8bmxeits 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angll6 7 4xe/sm8i tjesmr9e is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/7 e sj8sem6i 9l/tx4rms without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run*hwp1wd ya0ij03zm,ssos(3k 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 ogjo3mr;p+ t:t r mvd)6f radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m iei ,*jw j7upf:7 lush80r;dsjs 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 uniformlnq0oid( qm 7(cy in a horizontal circle of radius 0.50ni(q(md 7c qo00
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 t(n; )4l8oo gevcduu3race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circ ;v ng8()4l3deotuu ocular 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 of a proton of 5s.zdxhan -nc2z:o3a) k/n mhmass $1.67 \times 10^{-27} \; kg$ 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 tkd1z:yxrf :1 on a 70-kg person standing on the Earth, due to the Moon? The mass of the Moon is zykrt:11 f:x d$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational att t+0wc l.cysh:ractive force between two masses is F. If the masses are moved to half of their initi .t cw:l0hcys+al distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Spg3tysm *y1t xxk4o (np 3n/g7un, at what distance from the Earth will the gravitational forces due to the Sun anm3 4tgppx(ts 7g3 nonkx1*/yyd 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 i gnuta c/.16dns $7.4 \times 10^{22} \; kg$ 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 distan jpw*t4w5j5qq n;zg k7ui.1q gce above the Earth equal to the*w4j5;qz k ngu qjwqtp1.57 gi radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At whan +g8dwxz-mzy wjx)+8 t distance above the Earth's surface will the acceleration )xnz w8-w xy+d zm+8gjof gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a di. s7-u jhhr.y9a4xz gsujq(: zstance above its surface equal to 3 times the radius ofh s:r7. 9y(u-z haugjs.4xjzq Mars. 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 planet's center, the acceleratifyb8 ,rxp*+ze1mu e f1on of gravity i+zf,u1b18 xe*efmpry s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 uq5anx gi 4 h1c)qd;g2 gci7.g4rqm :51hqsxtN on the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r abo5hc h7 5n121.4xg4gqisgdc mq i;)xrg:auq tqve the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change whe3an, zow8gdy9akw9j u(y;d4 mn he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth i ,k(9;m 4aow jwd9dy8z3naguy s $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a3;f99h tw-ez rosaj:c point 3r above the Earth's surface. What is the satellite's whacwofzr3 es99 t:j;-eight?

  A spherically symmetric planet has four times the Earth's ma,)vo/,i ocep:t( zh uess and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Eaeo,t/v,och :) uei zp(rth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, witbc ,brh/ng f rr1f502wh thenwc10,f/fb 2 r brg5rh Earth between the Moon and 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 transpoz*xao 5 8bh,vtrted 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 just skin ur;k 1zhwb6i,62 .ee 3q8g qtsixk1d5fnu2kms the surface of the Earth). What is the speed of the satellite? (The mean radius of tt kswu2;.15f821knzx,n bgq d63u6e iierkq hhe Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skims e7e r .q1*cwos0m+o7qdf/ jw uthe surface of the Earth). How long does it take to make onj*rm/1d eoqwwf +cq us7eo0 7.e 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 5npfxv n2 d(tusa9i: 3is observed to have a period of 89 min. What is the massuxpsdn 95fa 2ni(tv 3: of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametercm5qgf5br/ vz2bb 2q9 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 a ra 8zevd hth9ep igm5/f* ;p(cyohc.i-*dius 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 p 8:co h2c7mmz bceh53orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete mz me5obpcchh c723:8 an orbit?

  The planet Jupiter is e+17cc k;ijolaw+ (-w mtue 7g$7.78 \times 10^{11} \; m$ 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 tokdw: d+ (7hh x,r9ce8nnp nsca /u;h1o orbit the Sun once. What is the average dis9 dsxuhrohcd1n p/:,kc (+a wnn 7e;8htance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)