Is it possible for an object moving with a constant speed to accelerat*8w)gbwcpk+o-am r, 0z( b efve? Explaivfwk8 ,pzb - ec mo+(wa0gr*b)n.

  Consider a particle moving with constant speed such that its acceleration o on5xumn,kfjlw43o3 2f constant magnitude is always perpenn,3x4ujmlo5 o3k2 wf ndicular to its velocity.

  An object moves in a circular path at a constant , lis*bh4/ czxqp(x 3 u9a;itdspeed. Compare the direction of the object's velocity and acceleration vectors.q xiz;xbs9(l phd3*4/ ait, cu

  When an object experiences uniform circular motion, the wml jz80+cnnilgvjy h0r980- direction of the accelerationcrlhyz lwnm80gj8-0 9+vin 0j is

  Consider a particle moving with constant speed swa/xwl r77i 1iuch that its acceleration of constant magnitude is always pe1wr/xa w7i7il rpendicular to its velocity.

  What type of acceleration does an object moving with constant b zz 0+fg0:byt5v2 zqjspeed in a circular path j tbzzq0y+ 2f gvb0z:5experience?

  What force is needed to make an object move in ar.m8dx4w lgu0 circle?

  When an object experiences uniform circular motion, the d-f+ f)f2xog mpirection of the net force is ff)go2px+m-f

  A roller coaster car is on a track that forms a circular loop in t9zxr;av/ y;f1 s beamlx42( fuhe 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 accelerati aex; 1mvf au4b;/flszr( 29yxon at this point?

  A roller coaster car (mass = M) is on a track that forms a circular w ,l 72shmc67vhnd(d jloop (radius = r) in the ver7 2dlsdh (,jvnc7m6hw tical 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 point?

  A pilot executes a vertical di/ms7ve ghw;)3u xu1 -crg5erave then follows a semi-circular arc until it is going straight up. Just as thm )v5ah13r -wc7guere/sx ug;e 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 kvjpqpil:h 5 * ;*g)epradius $r$ 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 constanrs 4 1vhg)ysj mls45p(t speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as ihym1lr4p sgs( 5v )sj4t goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a vjgv v/pwj21 2constant speed v. Then it goes around a cuj/2vv2 w 1vgjprve of radius 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 with speed3lkpa hsgm988 ihp0q4ro;q +i v. If the 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 magprkqia48l;osp h 9ih m038q+ gnitude to

  Two horizontal curves on a bobsled run are banked atcrc1(hjlp7.2k) hwewg kt c 26 the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay onc2wlgk)w2pte .c6 j crh7hk(1 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 notgcxwjyasl0tr.5s. j j)u0 w(bi3d -:k constant, but increases upward from th(x)saly.jgj ks- b0c t0ij wrd.3uw: 5e horizontal. 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 circular path5aq o/8vc+/ud ddtv/p to have both centripetal and tangentiavodu8+c/qpv d5 /t/dal acceleration?

  The gravitational force between two objects is proportionalv ;mus-.cbj* r to

  The gravitational force between two objects is inves l r5q8tx 8 vwl-cdk,11v/um9khka-grsely proportional to

  Two objects attract each other gravitationt 9nc kda1c2xjbt: /u8ally. If the distance between their centers i:2tx/n8cc1j k 9bdau ts cut in half, the gravitational force

  Two objects, with masses 3d+ (gbpp 6f2ki aypi*21z(2ut lshc k$m_{1}$ 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 i)p -buy d56qs3q8fqe$m_{1}$ 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 gravi68 rly4jb:8fw gwt,w utation.

  Compared to its mass on the Earth, the mass of + -xy8 yccl. 9ak yg)0pbx;eyzan object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what 14ix n0ys ms*cjo*gj6txh.c, it is on Earth. An objecy jjxox 6 1 .c0gti4sh*,n*msct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away 3k.il 09zl0+fw(txe2 gt bo ajfrom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the puipwp1txj 10l1ll of Earth's grav1ljt1 ip1pw0x ity?

  Suppose a satellite were orbiting the Eartkibdkc9,pbkd g; a5)te628k/n 4ham3w q kop0h just above the surface. What is its centripetal accelerm5bk9nk a6kc2,kp )b;/w ithdoa4gp 8qd 3ek0ation?

  A hypothetical planet has a mass of half that oe x-*/d padhx0f the Earth and a radius of twice that of the Earth. What is the acceleration*epxx-d/dah 0 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-sixth what it is on h7 sw/:cxqws) yt wgwnuk 6/;(vr0mm ;Earth. The radius of the Moon is one-fourth that of the Earth. m;ugvw w7(r : yh 6nc;w//w) kts0mxqs What is the Moon's mass compared to the Earth's?

  Two planets have the se jnh:.hwuc *g 5y4id2ame surface gravity, but planet B has twice the radius of planet A. If planet A has mass d*nec g4w5:u2.ihh yj m, what is the mass of planet B?

  Two planets have the same surface gravityg-d ipol3;lsq 3 p1/yr, but planet B has twice the mass of planet A. dolp3-r1 /lq g;ps3iyIf planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circul (ru 19)g2z1o- jil io1dgpsblar orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital vejl(god1-ir z)sgp l2911boiu locity?

  Satellite A has twice the mass of satellite B, and 40ozaa,ba6k v1hb; puksay-5rotates in the same orbit. Compare the two satellite's sp5 ku1ks bov6hpy4,-aaz0baa ;eeds.

  A person is standing oewo:+ dwo (k.vn a scale in an elevator accelerating downward. Compare the reading on the scale to the person's t(wd+:.owvok erue weight.

  Who was the first person to realize that the planets move in elliptical paths ars bb2ac3 1.eihk+fdg* ound thcshf ake*id2b.g 1+b3 e Sun?

  The speed of Halley's Comet, while traveling in its elliptical x5bw/a: v3 pn.kalu4 yorbit around the Sun,ulw/ k354ny xba pv.a:

  Let the average orbid uyxk1jhp9htks 8* 7:tal radius of a planet be R. Let the orbital period be T. What upt9ks 8xhy*1 j7hk :dquantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in t,)j;g1nn u:nh)j m:jf,jp pvphe galaxy Andromeda, with the same orbital diameter as the Earth a)jm n;p):jn pun:pj,g,hj1v fround 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 thepv* tc0iin **z Earth to the Sun is defined as one "astronomical unit" (AU). An zn*ti vci0** pasteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.:q 5 ips/zn8f5/re rfeyhi8c0

  List the four fundamental forces **c g2hpi93dpd 3ooyoin nature.

  An object moves with a constant speed of 30 m/s on a circular track eol:bp20w* bai(yf c2of radius 152*fbloc2eapyiw (:b00 m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Whamwrtvr/(0 )ott is the maximum speed around a curve with twice the radius? )orv(w0 t r/mt(Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a b1clb.+ r7mlzp +kt. py kri56picycle wheel of diameter 70 cm when the bike is movi5kytrpbpc z 6+i. m1r7kl+l.png 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is lb ebk1dtvf1uuc/a.6u 75+ dh kocated 0.200 m from the axis. What is the centripetd.+516u vucdabh/1fk7keut b al acceleration?

  How many revolutions per minute must a h - n c1,;,r )jrde3njr;mmvowcircular, rotating space station of radius 1000 m rotate to produce an artificial gravit;mv)dm r ;crn3enjwj,oh ,-r1y of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turnu ddihj8p96+ z zq(eu5 at 96.5 km/h. What is the centripetal force on the motorcyc8 ue95hp6( zz+jqdidule?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The sy qq5oe.cn4 vb7stem is whirled in a horizontal circular 7c4noqb. 5 eqvpath. 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 attached to a strong string and d*-o x(umsj;i whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 tdo-x;m(j i* suimes 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 whj+ zj wr)p3ns2jldv:.fqxu3*irled in a vertical circle of radius r. At the exact bottom of the path the ten* r d.z 323)spwlnjfxv+j ujq:sion 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 eaj 3hqn52rey; b6cf /oxperiences an acceleration of 4g when pulling out of the dive. W562y ajen ocbfrh/3 q;hat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the centery4qs+a rf x(gwzqtk o7z61-; j of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat wo r s+x;z4qqy(wtj a zf1gk-67ith only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can,, cfhjv iqfi t(; 62z9o5vmao stand is about seven times his weight. What is the mint5hz(mi jaoc6,q;9off2 vv , iimum radius 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 horizontal curve with the tire-hd 60xrs.qg r2(klgn j)xc;os 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 t; h0 qg6k.- dron c2(g)lrjxsxires and each road surface.)

  A car is negotiating a flatb bj e1eoo3j.6nm*u6 p curve of radius 50 m with a speed of 20 m/s. The centripnopu* .jmeob31 6b 6ejetal force provided 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 at a speed of 1g+- djfsf;m)vn kf /9k4 m/s. What must be the minimum coefficient of friction between the tires and the road for thfn/9;) svkjf gmdk+f-e car to make the turn?

  A car is moving with a constant speed v around a level curve6b-0pt60luu d og k-vi. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is t60 d -ou6luv gptib-0ko stay on the road?

  What minimum banking angle is required for an Olympic bobsled to neg*l*jfm7 e,f mhkc xx7x 83p2+sqqp.i( latu8kotiate a 100-m radius turn at 35 m/s without skidding? (Ignhme7fp k,ixll j.c 8*2q7x * sk(qf+pxt8uma3 ore friction.)

  A horizontal curve on a bobsled run is banked at:x sn;b+bx/qf+2: c vpypnx 0a 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 radif)hw a;it lsl4(c-z03 nnu7d:zc t +vrus 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bqarovb5/5xx*uc( x ,fanked 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 ac:c: 2-ysbu0dbu v r8tx*njs* string is revolving uniformly in a horizontal circle of radiusrv:8t2bs-ynds j*:ccxb 0uu * 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 accelerates at a uniform rate to 9h 2x9+(n fuz d++ vb01b mialps;tqsra speed of 45 m/s in 15 s, moving on a circularsu9+stl b+bd(aqh0vx 9 i2z;n+r fp m1 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 6w,y6 eo7 d+6c.v p dzmha*uky+, nuokof 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 person standis9qnvnr0xx9 zuj 2 11tng on the Earth, due to the Moon? The mass n2ux tnj1s 9vx z10rq9of 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 fhcq2l*8 )kgoy fic ap *,gs3lrz:so1*orce between two masses is F. If the masses are mo rsg*cly api*g ,q3l8z2s*)fkhoo 1:cved to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from th14 j 2)ldh m,t,hudcale Earth will the gravitational forces due to theuh4cd1 ,,)2dthl la mj 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 igqoaup p 4x.(-q;t ov1yp69mjs $7.4 \times 10^{22} \; kg$ 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" a;v qk.bo (mo*lt a distance above the Earth equal to the r b*vqk;o(m.lo adius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will5 9lj;jpqjz) f( wqox) the acceleration o(fzj)ql9)qjp o 5;w xjf gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance aboe47 x j*ho*5ib b7garave its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity oner b7aajbg*oi7 *54hx the surface of Mars, is

  At a distance of 14000 km from some planet's center, thkpx +qe ck rb/+.zumdhantr 7o(vuo 9 +5u3+a-e acceleration of gravity/k r-damcx3+r+5uubzk.p nvu+t +7q e(9 ohoa is $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 4322q yc/xo)g:krzrm3h6 gy,)c x N on the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is2,r)/xcq )y3homgz y6 cxkgr : its weight?

  By how many newtons does the weight of a 100-kg person change when he goehrwgg4bp 2v08*1 4pa t,ndyabs from sea level to an altitude of 5000 hawn gt y4,180gb2*bp v4prad 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 pg lgr ar*g759o ( :xqzfrw8+fyoint 3r above the Earth's surface. What is the satellite +9f8lgqxr(5y rw :rggafz *o7's weight?

  A spherically symmetric planet has four times the Earth's mass * j75e g;iwlqjand twice its radius. If a jar of peanut butter weighs 12 N on the surfac5*liqj; 7gwj ee of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lieaz +d-va5 ng/xr3a *zua/v*zr on the same line, with the Earth between the Moon an agau/+zz/ anxrvrd5* -3zav*d 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 trzr2 g se3wl4(qansported 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., itdwi8,-f6uidq x 9+hk v just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earthd,9+q u6wi8 fv-kdhi x is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low dv b7h ;pu8ik*circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius o7 *h8kp;dubvif the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earwgm0-w v s; ikqv+zgl1h-h571qlm f,dth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Eart mvfl+w1qhqwdz;5s g mh1 -7gi ,0vlk-h is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupit(1ghbtzi+6cr pv:y u *er, 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 au;rj yc r6e:;o 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 l sfx ;o* 3ojzw6-w0aaorbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete o30;6ow sfw zaxo- laj*ne orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isyx ur 50h y9 wbu17nrub-n;:hbjb.fz3 $7.78 \times 10^{11} \; m$ 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 yew .p s4v3z5,l pusdwy ug6k+;rars to orbit the Sun once. What is the average distance from Jupiteuy4.wzp l ,sprw5 dvk6s3;g+u r to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)