Is it possible for an object moving with a constant speed to ak,x6y ;;jxo h1c cgq6wccelerate? Explainx1 cwxo gc;,hq;6kjy 6.

  Consider a particle moving withfou.+v 3 m95wjx+i fbfjlt6:r constant speed such that its acceleration of constantvwb+fi5f3f9 .6uj j+:mo lrtx magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a conp pi bd ec,v536- ybdlb;3c1xfstant speed. Compare the direction of the object's velocity and acceleration byi-e b3165 3p,bdfpc;x vldc vectors.

  When an object experiences unifobd 9q ufvpu if1w)8x,-rm circular motion, the direction of the acceleration is ipwdf1vu9-b8)qu ,fx

  Consider a particle moving with constant speed s4w2uk)p;nc 9b ns+xmduch that its acceleration of constant mn p4)cn mu+xwbk29s ;dagnitude is always perpendicular to its velocity.

  What type of acceleration does ;6g8 ep 1y0yadu-amwfan object moving with constant speed in a circular path experien8emyf 0 -dgaauw1 6y;pce?

  What force is needed to make an object move in3wi2 .o-8 oi6nuvj lo42bgvh d a circle?

  When an object experiences uniform circuy xwpy4;xwz mo6ay/+,lar motion, the direction of the net form ;+w4/xapw,y 6oyzxyce is

  A roller coaster car is on a track that forms a circular l45 ie oo:m 3aedeg08jjoop 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 accel053goaoj8 4m eijeed: eration at this point?

  A roller coaster car (ma+qdhfp.iuzi:; * eh71lwna5sss = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car i1 inhh*pls7ie a:q u+fzw5;.d s 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 dive then follows a semi-ci b d49zwl:v,zorcular arc until it is going straight up. Just as the oz:v l4,bzd9wplane 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 radez +z; n-m7jw gvj7uo5pe91woius $r$ 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 speevg28a8 mf(y ()lvyhzfw(5le ed 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 curvw((2a8lem8()fl h z yfe 5yvvge for the second time, compared to the first time?

  A car goes around a curve of radius r at a consuo1vdd31v;cppnq+a0 q9rv t 1tant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it pp111q v90 vrc;3t+nudvqoadgoes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with s..celit0+ dq;jfi1 6xn s gbe,peed v. If the road is frictionless due to ice, the car can still negotiate .ii+sxjegc ;nq,lt0edb6. f 1the curve if the horizontal 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 g kk7fh6yz0m+one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller rzg7f06+kk my hadius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympich(t/l,eild r ;5e, 5kefef xs3 bobsled track is not constant, but increases upward from the horizont r;hk/,e f(3t5xie 5elfed, slal. 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 path to havexmnr)hrmd7o2 gm3 b18 both centripetal and tangential accelerabm1)ho r7mr28 xm 3dngtion?

  The gravitational force between two objaz j*oe)*g0 qb -:m d3kq+fsg).jfjbf +tgmc5ects is proportional to

  The gravitational force between two objects is inverac sw 5-eh3/e 4vigj.bsely proportional to

  Two objects attract each other gra u- e0npqr. 5:6sfmxk(ca(ilrvitationally. If the distance between their centers is cut in half, the grps0x:a (u6 crk(mlf5i.nqe- r avitational force

  Two objects, with massesih:mo ae/4z4 pca9v,w 4re(r2c lk9id $m_{1}$ 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 mass+mph7+n )fswy p2xd6zes $m_{1}$ 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 -tqhribn.b6 9ation.

  Compared to its mass on the Earth, the mass of an object o9 7l9 hh;,n;k vtlrfmen the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earthqv2epfv2-sbw-r;ww ;5)t jr t . An objectjt ew--vv 5r2; s)tfw b2;wqrp of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface,rpk.juf far wu2q wbl,i6 fxh)6z2/*, the rocket's weight

  A spaceship is traveling to the Moon. Ak:es8h cy7yu+ t what point is it beyond the pull of Earth's grav ky+ es:y8c7huity?

  Suppose a satellite were orbiting the Earth just above the surface. What is itseeespn31gxqr*/.8- jrl s8 c rhxfk. cb2mp+: centripeta.br/*.slc2mc jhe3rxpns x e +pq18gf: ker8-l acceleration?

  A hypothetical planet has a mass of half that of thea 3ct+9dqc ky5z w3c)0fl5yax Earth and a radius of twice that of the Earth. What is the acceleration due to gravit cf wzy39 l0+d)5xac35tyc aqky on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moooh5b ps e5suk,x il5;pp ;y8k4n is one-sixth what it is on Earth. The radius of the Moon is one-fourth tiulx b ey85;so h skpp4k5p5;,hat of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B hasfn3pcdw 4 fw d*ps;,*c twice the radius of planet A. If planet3c n*d * sfp,c;w4pwfd A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B ht ae 8)x2e hgb/wr;/jgas twice the mass of planet A. If planet A has radius r, what is the radius of plaggj r) ebxhw/;e 28/atnet B?

  Consider a small satellilb*n*w -(hmybq(t5qv te moving in a circular orbit (radius r) about a spherical planet (mass M). Whicb5q*mynlt b-q(v (h* wh expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of sat,2 rpy b4k5 :rl.pz(. mndbrv3 tt5t,jmp q/ptellite B, and rotates in the same orbit. Compare the two satellite's speeds. brppp(dmtql, j 4pbv/ttnz5:3r2 ky5.tr, m.

  A person is standing on a scale in an elevator accelerating 9v nxc5s47 r9od, vtkddownward. Compare the reading on the scale to the perkxddc5otvs9 49 v, r7nson's true weight.

  Who was the first person to realize that the planets move in i ;j; fk(y 02zj40, sou fqgc3ckmqr5selliptical paths around o cimjq5,;c(fs 4rq02fuzykj0 3 k;gsthe Sun?

  The speed of Halley's 4h/yyjw69 bot wym mpb.v-w42lx3 .xkComet, while traveling in its elliptical orbit around the Sun, khmw9olb.pt/y2j v3xw.- 6 wbxy m44y

  Let the average orbital radius of a planet be R. Let the orb9 mz sx,a+t0e / fxhjl6*8qitdital period be T. What quantity is constant for all planets orbiting x 0at*ds,/htj q8i9+e 6lxzmfthe Sun?

  A planet is discovered to orbit aroundfczpf2 t(tz 58 a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of ourc( 2ttf58zzp f Sun, 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 iknw mf)fmlz,/ 4s ;5sms defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Su sn ls wz4km),;mmf5/fn?

State Kepler's laws.4tlw0, nzla0qf ewh:d2+ qf+o

  List the four fundamental forceu-r,67oil pr1 f )wzqns in nature.

  An object moves with a constant sd-1 - pwark)obpeed of 30 m/s on a circular track of radius 150 m. What is the ac)p--b wkd a1orceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Whavm/m5 c 4u.;bh gom3v9o hf1fvr gyt13t is the maximum speed around a curmb91f/ 3 vm3cf4u.;o1ym h togh5vgvrve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal accvo +tzbh0zbb3 b;q 3+djbbj-8eleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/38tb b0- ;bb+z bv +objjqdz3hs?

  A point on a wheel rott8 ,ov8i gv/ mw1tvw+gating at 5.00 rev/s is located 0.200 m from the axis. What v8o,+mtv1 /iwvg8 twg is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space sw )2 5ta(3 lp aabveziuxtv.o0j+ 3z-r7 -gzvitation of radius 1000 m rotateju(07lazabzwg to v 3.)iveaxvtzir- p253+- to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mas2ago5b ,monnkcb7(q* s of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h 7c*mb q(bnoo2k,g na5. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the )* 6-c)ye wqgbohow0 qend of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the 0 gc*w bwo)-yehqo6 )qstring 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 whirlefv.bl1 wa+e3h fidg7 5 0vmgqom7h/a*- mi,hkd in a vertical circle of radius r. At the exact top of the path the tension in the shw7hb* f- v1.mq5mo7 h aveifk/g ,d l0gim3a+tring 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 ; raxxuu -35 1jmbp: hmf(m7d rl8gul+a strong string and whirled in a vertical circle of radius r. At th -1hpjf5r7 ul(lubg +m3;:mmurxxd8ae 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 by

  A jet plane flying 600 m/s experiences an ac8ndr*l-a1dm o*oj8 uyceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyi18d- d**oynlom8ua j rng?

  A pilot makes an outside vertical loop (in whiif4p8w s51 erxch the center of the loop is beneath him) of radius 8ei4sfw r1x5 p3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What is 97cuwv4k ti0 hthe min whi vktu7940cimum 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 radim .q46vqxce0cw rqz0 3us 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 same coefficienm 6.wqce 40z3qc rvx0qt 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 ot*j72mc ke7nco, nk/if 20 m/s. The centrk ,o*i /77cn2njtkmecipetal 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 l3rio2;c vfq9 fxs0f-+iz9i s of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to m io+29s0rfzcsf9ifv i;3 qx-lake the turn?

  A car is moving with a constant speed v around a level y g/lfc -t/*)xu7,ej fjgoq a3curve. The coefficient of friction between the tires and the road is 0.40. 3/fxft), coqljguage 7 j/- y* What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic pw zxsj ae6i:i 9:aq7mq-4n0r bobsled to negotiate a 100-m radius turn a 9:qpm4ii06-wxrenz 7 a :qjast 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bank y 7h/7mn-hwq auc.d;zed 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 angle ofnnn de.zml hfh .92yt16-m2hr $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is5s+,hx, fa ,f0lyu ;*r rstcdp 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 1f;bn,muard /f-kjq )c*fcs/ of a string is revolving uniformly in a horizontal circle of rad frujk q n1-;/mbcc/,)af *dsfius 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 i-,gh3imb*e ei93oqsu n the pit area, a race car accelerates at a uniform rate to a speed of 45 m/s u, em eqh3oig b*9-is3in 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 protontt7y,t wr4(-m a wz4jf3l jeo: 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 ond,/19qrhm++s q(byoz toeh +p a 70-kg person standing on the Earth, due to the Moon? The mass ,o1+qt zprhb(9 shq oem+/d +yof 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 bethvq- t.r :-rm(yhu0z tween two masses is F. If the masses are moved to half of their initial dist u(0: qt.z-t-rhymvrh ance, what is the gravitational attractive force?

  For a spacecraft goin0h(j; n5d 4s gfi;rhvtg from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth ;f4(n0dig5jst vh ;hr 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 is uru,z2d 6g-ht $7.4 \times 10^{22} \; kg$ 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 dista 7 0rz43gs.lf9rgrvhvnce above the Earth equal to the rah.gzvls 34rvrrgf 7 90dius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surf+vxp2aik: cum xw8i:7 ace will the acceleration of gravik x2:ix +:c7pua mv8wity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfacj109 bjui,dzm e equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, amb,j1 9 ziu0jds 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 12 qwwtvd0 t:mg /3mag)ecgu7of gravity/g c2t)1gudmq m0a3e 7vtw :wg is $32 \; m/s^2$. 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. t5,qydft75j j (24j)0afdkzgtq w-toThe Earth has radius r. If the object is raised to a height of 3r above the Earth's surfa( )zj-q0 qwt t7go2tfy4ad5tkj ,jd5 fce, what is its weight?

  By how many newtons does tv.4: imxnr ippdnl( 63he weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m?v l 6xn3ni.(:4di rmpp (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of raw2ezp5((wspzw** n mass 100 kg is at a point 3r above the Earth's surface. What is the satellitezz( p5 ww(nes*2p*rwa 's weight?

  A spherically symmetric planet has four times the Earth'sk 1*pj4y hh:xz mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, ho4z j:x*hhyp 1kw much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, andxhye8chz+1bf yx 261x g3)as)osfic 3 Sun all lie on the same line, with the Earth between the Moon and thff 6x1h8c2siy33a) b o)xc+yg1xzshe e 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 transporteuhgk4xf. ,l/gd jh47md 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 cir 8+w)pp- qmleicular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of thw)-l + i8epmqpe satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cijma bd- 2ql:m02nvvd k,f2o.krcular 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 radiusj022 .k,dn:ldkf mvao2q-vmb of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the suexg 8ey)3k0 uxrface of the Earth. It is observed to have a 0 gxxy3eke)8 uperiod of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jup zz wzco0s (1tuu 6qt;fwri35+iter, 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 e)c 5aww9wt-b 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 j c x/ fuv-:lvm,vg(2norbital radius r, and moon B has orbital radius 4r. Moon A takesj n v/:x(l2 vg,cvmf-u 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 5r;kcs*j (i5 kaams6p$7.78 \times 10^{11} \; m$ 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 the5 n5lt tmqzn94g7pk p) Sun once. What is the average distance from 7lppn tq55 )zmkg nt94Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)