Is it possible for an object moving with a constant speed to accelerateufik6zfvf*ri6+5:g pg a4h; i? Explaini4fp fg f6u *ia; vhr6k:i+g5z.

  Consider a particle moving with constant:uws c3z,: g0f at-as cguw3;x speed such that its acceleration of constant magnitude is c ss ug3f0,w-xgwuc a;:t3a: zalways perpendicular to its velocity.

  An object moves in a circuq4;vgezoti 2f6+k vl0lar path at a constant speed. Compare the direction of the object's velocity a qlz40vvfoge;tik26+ nd acceleration vectors.

  When an object experiences uniform circular motn2 1+prjuoix )hpd6t1 ion, the direction of the acceleration r t2 1p16dpon +hij)xuis

  Consider a particle moving with constant speed such tha( :xk bahx-a pfv ogyz4xtan:4;7p (x5t its acceleration of constant magnitude (xxo7x5x;(fb4 vpht:kng- z a: 4aaypis always perpendicular to its velocity.

  What type of acceleration dolj4twh jw 8dj/o703sf es an object moving with constant speed in a circular path experisj30owhjdtlw 4j7 f8/ ence?

  What force is needed to make aem-* g xnl o1s/yc4m pnw+ot:1n object move in a circle?

  When an object experiences uniform circula3ld 1vmu4fuv9(rrpj ,r motion, the direction of the net forcj pum93(r1,fdlr u4vv e is

  A roller coaster caruwl)4z :xiz2 n is on a track that forms a circular loop in the vertical plane. If the ci:luz)w 42nz xar 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?

  A roller coaster car (mass = M) is on a track that forms a circular loo4-ozhg /ct gw/lf m0y ,uu3o0bp (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 ithg/y/bm00uo3, tco fwlzu-4g s speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc obqw8(7 hv+9nu gcc j2until it is going straight up. Just as the plane is at its lowesc7n+98jub(v wh 2ocg qt 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 radiuvv jnvm;y* qwy+s)b8ksc:.w (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 +khx-3pehl0gy9kp0p ser1h0 speed v. 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 time, compareh0p p0e-xp 1h9l 0 shker+gk3yd to the first time?

  A car goes around a curk12tjsg +e/jte*fr )d nb(bf;ve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on jesjeb1 b kg)f;*td2 +tf(nr/the car as it goes around the second curve, compared to the first?

  A car of mass m goes around3k 26z bjj /w ulln;0-j+dsydh a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontadj /jj -2 uw+dyzk60bhnl3ls;l component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one has5d4gaib3 w w6i twice thw6wb4 dg5a i3ie radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in r h 44tt,4pj; qtmv tb*dc7io.a turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled te*4mchdjttbi; rt .7p, tov4q4 am will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object movzucp.0ry94dmpv* fu /ing around a circular path to have both centripetal anrz0pmf uud 9c/y.4*vp d tangential acceleration?

  The gravitational force between two objects is propv/oisc96 p jmdn+r0e( ortional to

  The gravitational force bet;iwbw; e;,gzi4zn:za ween two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their c*l3+7v5cfauq gt + thaenters is cut in half, the gravitationalf +gau3cq+at 7 *tvh5l force

  Two objects, with masmb7rst;9-rodo0t bn*pt; ) xjses $m_{1}$ 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 masmcrq q2 h-pd+ s6u:5yygj 5k.bses $m_{1}$ 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 grav+4 ,;w-yr mqopl k5ikdp(yln 5itation.

  Compared to its mass-3.0 s *zmoxgwm,eo+jccv *cg on the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. Al2vm-m*lk /a zn objel kam-mvl *2/zct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'se1ozbg ng,m a6s(e zyx0: ,ms1 surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pullvp i ,oofw.q) w91msg/9(ictz of Earofcg/ p, 9.i1) vwoqzm (tisw9th's gravity?

  Suppose a satellite were orb/geck2-w6 bfts4)ma aiting the Earth just above the surface. What is its centripetal acceleration?m seta6/c -bg4f)a k2w

  A hypothetical planet has a mass of half that of the Eamjo scp0j r81gw-)5wp rth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, w)gwsj-rcm o p1pj50 8the acceleration due to gravity at the Earth?

  The acceleration of gravmhjec0 a dxspq,9;96lf.bkab6s r 4k4ity on the Moon is one-sixth what it is on Earth. The radius of the Mfm4px,sa6;e cj 4kl k6bsa h99bqr.d0oon is one-fourth that 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 twice t ts guynn+9o)1he radius of planet A. If planet1tun on)ys+g 9 A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the ma.m4lzwd,f5 ( ufs6xp tss of planet A. If planed45p.mltsu6f( xw ,zft A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbp6nq 7+kr7j4l ofk08p 8uvgllit (radius r) about a spherical planet (mass M)4l klkop 8uqrf+807v ngpl 67j. Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates+kgg ,6g ejii9 in the same orbit. Compare the two satellite's speeds. i+ieggkg 9j,6

  A person is standing on a scale in an elevator acceleru:iucx38ic hxm f9 vm5;/:nkqating downward. Compare the reading on the s/;nivh3qxc uum x:f5k mi: c89cale to the person's true weight.

  Who was the first pe.ct 32*icau c5qq /dvoz+gzae+dm(p* rson to realize that the planets move in elliptical paths around the Su(.mq /c+qz*di act* z vdpg+ eo3u52can?

  The speed of Halley's Comet, while traveling in its3 xeoe 8t5q u /rp91xswd5-ayq elliptical orbit around the 3xea8 r uoqepxw/dq-t9 1sy55Sun,

  Let the average orbital radius of a planet be R. Let the orbital period befo 1l/imq8 zn h2jyv5, T. What quantity is 2/,jy1nfh mq8iz5v loconstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witwavm (0,rqfc..8gph w h 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 w(vg ,w .ahpcfmr0 q8.that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth iz6blltg3 wfa(11 :po to the Sun is defined as one "astronomical unit" (AU). An asteroif1oz:l i16(plw gat3 bd orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.x vxa2-/pqnx2k f7u9v

  List the four fundamental forces in nafce2 ,a e koy(v0hb79iture.

  An object moves with a constant speed of 30 m/s on a circu f poy6c ul24jlr()(mk7j yy.ilar track of radius 150 m. What is the acceleration of the obklf j)(u rc2p.7y(ymiojly4 6 ject?

  The maximum speed around a level curve ixcx +evorvt 73(i5 2dqs 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume ax qxvov5recd 7t3 i2(+ll other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perchx97t n4bm9uimeter of a bicycle wheel of4 xbnuc79 9mht diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s istjt/h/flxkv4;.* gd aw f9ww ifd-+ -g located 0.200 m from the axis. What is the cenf;kxf tf + -h.vg/ij*wg4 l/wd-9watd tripetal acceleration?

  How many revolutions pey( z 6,uxyk6tjr minute must a circular, rotating space station of radius 10j,xky(uy6 6 tz00 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a macufevpl0n-j l675uv.m *yj m:ss of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. W e0l-cy:n m.u ujp65*vj7flmvhat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is m0 bgsq*mq:j;vq;z+n.oz:s q gwyw) .whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 ;* :q) ;+oqszwgym.b qz0m g: nqvj.swN. 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 0((1 frffrjcs vertical circle of r1(fcs(0ffrrj adius r. At the exact 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 strong string and whirled in a vertical cip/z9kw p;2 ncircle of radius r. At the exact bottom of the path the tension in the string is 3 times the stockz /29;pnwp ine's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiie*hgys i8p:4 ences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the lg *pse:8yi 4hioop in which the plane is flying?

  A pilot makes an outside vertical loop (+ )e6d5./b j3epidpdsk of2zm 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 on62pbdso5 m d+ fk 3e)i/pjed.ze-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times /6ezqw z ;q c:bbooe5-his weight. What is the minimum radius of cu:bw5zq6/qeo cz -b eo;rvature 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 a ak:v9e :4:-p*br fy bzp*aahgv0u nu;n 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car rouna:y:zf*;ug :bpab n-a9u*k r 0h vev4pd 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 of 20 m/s. The c*tz0jml6n ou k(tl3;ve6(phgentripetal k tlo( vpmlne03u6;(6*hzgj tforce 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 14 m/s+sa u78faz1+e z aq(lujup*+r. What must be the minimum coefficient of friction between the tires and the road f*81afu+ ae+ qsj 7 r+pu(zluzaor the car to make the turn?

  A car is moving with i:wxl)wnm7 wnzo4 ;7 ha constant speed 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 the car is to stay on the roano: 47x wl;iwzn)mwh7d?

  What minimum banking angle is requiredu(j :-lkboi 5k for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? jb kiu:o l5-(k(Ignore friction.)

  A horizontal curve on a bo7;psttmeus jkq59 j5js b//x:r c ,4rlbsled 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,b 85(.r mndmhat ob7u of radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedfz1 c,0 y*u/vjw nntxd7ea) 8v 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 unifor l-dlob u64e*wmly in a horizontal circle of radius 0.5 bd*l6oeul4w-00
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 bp4nrq e*t f7fyf2b-:uniform rate to a speed of 45 2*ffebypt:-fb7nq4 r 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 of a proton of soy ed7 9el( 3as.fbo(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 standing on the Earth, k)3iv rb5.vo;( zc 01sjaopqk due to the Moon? The mass of v rskqk ; aj5o0p.(zib1 vo)3cthe 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 masses is F. If k lhn;kglsdi14pzt77rg5b .w7 9: qz fthe masses are moved to half of their initial distance, what is the gravitagp:w9.i tgs5kn fzdl77q 4lr17;kh bztional attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from thy-h.(s(uenv j 5,ufj ve Earth will the gravitational forcejjnfu,u vyv s(.5h (-es 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 fzzwbpt5e a.x263sp2tf;c)q 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"bow,y0bu0r ) * loobj( at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravity0*o 0r,(o) ybwu jblbo?

  The radius of the Earth is R. At what distance above the Earth's surface will t-fmav*kxqhr; 3k,) xi0rw9p jhe acceleratxwvx- rq9khrk, ;f*a)pjmi0 3ion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 tiu1kf/ld u(u8sx*a3 fny9/6+rqr e +ehq)kzf w mes the radius of Mars. The acceleration of gravity of the nq1yhkke3/d zf68ffx/(lu asr* u) qr9+we+u 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 grw6ewcu;2c+v. w et,cve- ccb ,avity is ;.v,ue+ 2cvw-c tccb w6e e,cw$32 \; m/s^2$. 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 Eartht2lq- iss01bo has radius r. If the object is raised to a height of 3r above t0ots2qbi1s- lhe Earth's surface, what is its weight?

  By how many newtons does dy 3yii1grcmim8f2r6 o57l*a4*puu othe weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth rl4 ygi2muo d67u* rpmoify* 8i5ac 13is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above the E/-zur z)o 0 jwxf *jb7zrl7mu;arth's surface. Wh07;7)jb* u xw-zzr m z/ruljfoat is the satellite's weight?

  A spherically symmetric planet has fourwdj h.g ,: dtv51;rmuu times the Earth's mass and twice its radius. If a jar of peanut bug ;:1.vu,hmtdd5jr uwtter 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 cd(n 9il29qj2vki u9lall lie on the same line, with the Earl(i u9 922qnjl9 dickvth 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 transported to7 r3f kxsgr9-q 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 circuhrf8s 5cu: 7xri/:zsrlar orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of:8r5 7uzcsr sx ifh/r: the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the frqpsj,uydd,a,)1 r- Earth (i.e., it just skims the surface of the Earth). How long does it take to make one ,1d s )dar-fj, ryup,qrevolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circu j5f- ;v1wtxbqhbwm 0/eq n.e5lar orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. W qfqb/nj mtx15v- hew eb5.;0what is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diaxk41:i bvbzh+1 ,qfjkmeter 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 plane2r1. swg*zkqbt 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 ndmecid 7qg4axz- g )9+ykc/6iearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 d /cxga 4)+ zk-qicyid6 79emdgays to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is flj cqhjgrj: v *+9-)c$7.78 \times 10^{11} \; m$ 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. What is the average g(f):93k psqng-6 kugqg*bo fdistance from Jupiter to the Sun? (Thubpg nqf9okg ksg)6f -g:*q3(e distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)