Is it possible for an object m lt oiyxl, xbcf45xu7b+ /l*6roving with a constant speed to accelerate? Explainuy,lt b lx7f5ri+ *x64co/ blx.

  Consider a particle moving with constant speed such that its ac)p)oiz: esr38 wmlk 8iceleration of constant magnitude is alwayip)rmi8s:z8k ) w o3els perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare dbip*2 ppsee x,472*b1palv p the direction of the object's velocity and acceleraievdexb *lppb * 224psp1,7pation vectors.

  When an object experien2)0s9 84kj zp/ ytwg snl: umnvypn60lces uniform circular motion, the direction of the acceleratvslsky/pm4 0tu8j)y:2p0n gz wn6n9l ion is

  Consider a particle move *yp6/gjc-f2zk:k hfing with constant speed such that its acceleration of constant magnitude is always pfekk2y*h :6cf/gz - jperpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a qswn.;oi1pa sf3 q vq;vr569hw: , ocmcircular p6m3,qwwsaqnpi .oro9; vq 51;vcf:sh ath experience?

  What force is needed to make an object move in a circle 7wyvkxzh 4x8sh /5xf4?

  When an object experiences uniform circular motioz.z 2-1e+d.toxf8a ady8 lrnln, the direction of the net forlzo xnd.ay-tr1e+zlaf d28 8.ce is

  A roller coaster car is on a track that forms a circu7*ewc6r:r g aalar loop in the vertical plane. If the car is to just main*e:cr a7wg6r atain 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 = Mftk+hni z)6gqty1o 30fm /0 fy) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain cooqgz n 06mitff/h f+30y ytk)1ntact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertica pp)sb cy7- lc: 3cl0skk03s p-v(joqbl dive then follows a semi-circular arc until it is going 0p: 7s0c-sjk bcqyos)l3pkbcl(p3-vstraight up. Just as the 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 radir/e+tto),vjo0gfv *0 q ) iquuus $r$ 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 gs.1m b*vo 3)7tdu . 3jsyf z6kq:ks.xjxidd e:oes 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, compared to tsky bzuo3.idedv7tm3 x jd: .*s qsj.x1f6 ):khe first time?

  A car goes around a curve of radiuhsesz(lc 1rki18e) nj 4/ca7as r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force1a8 ( l)esnir/1s z4ckahcj7e 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 speed 2f6r h1btnfijf33 4 uev. If the road is frictire34ubthjn2 1i3 6fffonless 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 to

  Two horizontal curves on a bo +/;8 kk1eowcgrz8hlu: qinb 2bsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the rqw ; /ch8rgl2+1ub :kink8eozun) 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 not constant, buttr/pmjb6 my(1 increases upward from the horizontal. Coming around a turn, the bobsled team wil/mpt j1m (6rbyl intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an objek(4 ,-kyfu1 vt-hxta/ a9lemn ct moving around a circular path to have both centripetal and tangential accelev-f ahu4( 9-/tetl ,ykkma 1xnration?

  The gravitational force between two objects8keq6pcee xr(87 79 zy dymcs4plgi4* is proportional to

  The gravitational force between two objects is int+efjvlp0mtst4 7j0s6w x,m:versely proportional to

  Two objects attract each other gravitationally. If the vq ap p/hf:cy8zi b+4,distance between their centers is cut in half, the gri/bqz,f+c4pya h8vp : avitational force

  Two objects, with massa 3yc aml;x-4hes $m_{1}$ 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 ma1n 5)9sn7sfdnh1v+qd )uq-*jpajv b xsses $m_{1}$ 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 o h sk,;1nk4lyqf universal gravitation.

  Compared to its mass on the Earth, the mass of an objcxov+d6w) jf5 ect on the Moon is

  The acceleration of gravity on . s l)ksn8q;hwthe Moon is one-sixth what it is on Earth. An object ofk n8sslqh;w.) mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fra) je7sf .vcc rkwv0//om the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is i( +l +xtazj0h5fv2:0szjc ytgt beyond the pull of Eartha+2f +:0 ysxgjz5 htj0(tlzv c's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. What is iwsyxxc 18/f) pwdgc*0 l5qt1kts centripetalt 10lx psg 5* c/cxyk1)wqf8wd acceleration?

  A hypothetical planet has a mass of half thatdkju8f(ia fj c.g z65ier-28ld;on1 l of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the plau; ik ijezfndg68lj5fc2rad.(8l- o1net in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravitcwo i6.8zit0wy on the Moon is one-sixth what it is on Earth. The radius of w86iicwz.ot0 the Moon 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)rc .f chrw,oatwv ,)0 twice the radius of planet A. If planet A has mass m,ht crw c))r.,f0 ,waov what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice t1buru*im6c1ui 8cg;l gu g0-the mass of planet A. If planetu;ggm8 u6c c1- ug1il0ut bri* A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheruy6/yri7 nd6+lch rj0cwe l-+icaln+j rr 60 -+w/el lyci7ycduh6 planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit.n:a o(iu )pnxx/t.b:0tqs5ygqxay,/ Compare the two saty iqpxg ox5::n /sq/a(anbx.)ytt 0,uellite's speeds.

  A person is standing on a scale in an elevator accgd.fo 9onu6i 1,pvyx*elerating downward. Compare the reading on the scale to the persyonv .ipu,1dg*fo69 xon's true weight.

  Who was the first person to realize that the planets move in elli 1frbzt8qpys8e c9:2iptical paths arourfyi9t zs8p2 c8 bqe:1nd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around t0q:ldwg: rbnb57 3tvehe Sun,:n t eb5g3v:0dlrb 7qw

  Let the average orbital radius of a planet be R. Let th 5ysrujxgw,(y-;h f q.e orbital period be T. What quantity is constant for all planets h(xf.srw5;,gu-jy qy orbiting the Sun?

  A planet is discovered to or,(te ypteu4 g(bit around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that epte, tuy(4( gstar 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 the Earth to the Sun is defined u8x2 rqtnk3/ fas one "astronomical unit" (AU). ur3 k/q f8ntx2An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.x lk1l8 np)xoct0jii p v52p.)

  List the four fundamental z 01y3v4hl9tz:2 rkitanb:zg forces in nature.

  An object moves with a constant speed of 30 m/s on a circular tracgs 3ty*rvh a j6ye),:gk of radius 150 m. What is the acceleratiogrtg,*)yysej3 v:h 6 an of the object?

  The maximum speed around a level curve is 30.0 km/h. Why2 urf 47ulwa4at is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchangf2 47u4 wyaulred.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle5jy)c rd/ 1f6ktk8 cla wheel of diameter 70 cm when th1rkc 5ykfcl / 6jad)t8e bike is moving 8.0 m/s?

  A point on a wheel rotating 0v5o vw 7y ;jqp7+otnnat 5.00 rev/s is located 0.200 m from the axis. What is the centripetal aco+qtovyn pw7;5n v7j 0celeration?

  How many revolutions per minute must a circular, ry bvg,1qe xd9ucqwy+y*yo/ (,vq5(rootating space station of radius 1o 5yq(/yvo,exwubr g*d 9vcy +1qy(,q000 m rotate 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 at 9 su+b8:+u iby faim9bgbj85 -e6.5 km/h. What is the centripeby jiasbub-:9u+58i egmfb8+ tal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is um+trwpkr (vivh 1m5c5 c;4 qq(t wz/3whirled in a horizontal cirvirtmwmz35( +c qu phck;/t5r( 41 qvwcular 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 attached to a stronw ;r r3ez*:2z9dqbhcx g string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times 2d3wzr; xbcr:ehq*9zthe stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string fjnm nt67 1uqf3f*+xoand 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 spentj 7*+ ou6 mfff3xq1ned at this point is given by

  A jet plane flying 600 m/s experiences a9vrz1exhm4/a n acceleration of 4g when pulling out of the dive. What is the radius of curvature of t eav9/rm14zh xhe loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of theb;ibh:( 2a*; tbwsdsy loop is beneath him) of rh2a; :di( sybtb*w;s badius 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 is he going?

  The maximum force a pilot can stand is about )(qn 1hzynj/ bseven times his weight. What is the minimum radius of curn) q/ zyh(1jnbvature 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 witjuhsal 9; ht6/sn8xxb;08f a 4g6e tulg( mp(yh 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 be g ;hant68 ;elf(xy tgbph06mu/su9sjal (4x 8tween the car's tires and each road surface.)

  A car is negotiating a flat curve of radius kno9lin: yoxd9 89/5 kmg8f4*jl/x rj*cgbt j50 m with a speed of 20 m/s. The centripetal f 488/k:fb jnc xmj**loxr99tgodi y /5jlg kn9orce 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. tw+,j.j ib;ulWhat must be the minimum coefficient of friction between the tires and the road for the car to make;jiut, .jlb+ w the turn?

  A car is moving with a constant speed v aroun.3u 6rp/63tq vkx badld a level curve. The coefficient of friction between the tires and b6qlr.u3pakx36v dt/ the road is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is requip+/x.vtr1 o mured for an Olympic bobsled to negotiate a 100-m radius turn at trpo/ 1.mxuv+ 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankeda.la / s92/yckm0pczm 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 lj o07f f,np2gof $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked a/hggin5 x q0/jt $45^{\circ}$. 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 horizontal km +;ksas)a;o5cdgn /circle of ramn ca;kkg /ss;a+o5)ddius 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 unifor9) te ;td; z fp+jl4pgn7rf)nmm rate to a speed of 45 m/s in 15et 7;gf49 nnlt r;zjm))pdp f+ 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 protw/sp u.t+wo 2ton 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 person standing on the Ear e3nqrsi+, tx(h79sf mth, due to the Moon? The mass of thet r(q9xs7fmshie+ n, 3 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 the masses are :+nvx 0uif c jogrr0*79ypf i9moved to half of their initial 9rxrogv:iuj *9pnf 0 0if7cy+ distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward /x7 5ijc;rqip the Sun, at what distance from the Earth will the gravitational forces due to the Su/x;r5pi q jc7in 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( o6ma ;xiishwrna*: + 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 Eih 6:0o-yp,fw r(q3. wvbcgrnarth equal to the radius of the Earth. What is her acceleration due to graviy:fih 3r cnoprg(b.wqw 6,-0vty?

  The radius of the Earth is R. 8sm8mj4c+ ipe At what distance above the Earth's surface will the acceleration of gravmc j4m8+esi8pity be $4.9 \; m/s^2$?

  A satellite encircles Mars ltrnsru1b;*6at a distance above its surface equal to 3 times the radius of M r*1ls ;tr6bnuars. 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 acc(imvb7/ j0xr4 acmcn0eleration of gravity isc(4jmbxcm/ai7v r 0n0 $32 \; m/s^2$. 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. Tht49yvtiav dau4eiwl,6/ 3(si-tk* vn e Earth has radius r. If the object is raised to a height of 3r above the Earth's su*s/ tv3lvi4 i9anukw4-t i6dt ,y (evarface, what is its weight?

  By how many newtons does the weight of a 100-kg pe7qmz a+8h lwo8rson change when he goes from sea level ah 7w8 +q8zmloto 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 o* m, kka:jp+ivf mass 100 kg is at a point 3r above the Ea+ ajpk,ki: vm*rth's surface. What is the satellite's weight?

  A spherically symmetric planet h)u60w2 wwt rgi .*wqqls7u /akzq -3+2pnecqwas four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surfacewaw 2tuqwel2 3nskuwrq-/0z 6)cpq*.wq i 7g+ of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all l8 + 1 ql-bt4nf;7mozkhw.lrrtie on the same line, with the Earth between the Moon and the Sun. The Moon h+fr- lo;b8n1zl 4 wmqtkr7th. as 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 tran*7z1bjrt3 iclazp qib5):i k+sported 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 lqs9( ciryd)6 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 the Eair9cdsyq ( l)6rth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular or8tox:fh0ui q x:u9z*n/7qk)odd6 zd ebit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make ozun/xx d0 deo*t8 q: ku97q)fd:z6ioh ne 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 su un (;g f5dizzink079urface of the Earth. It is observed to have a period of 89 min. What is the massg9n5iz( zu0n k;dufi7 of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupits,*bnt:j: vdl ,u1zzaer, 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 orbitco1u og ik-t +u(h+qo.s 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 orbi4loz34b dzw) dtal radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How lowdlo4) b4dzz3 ng does it take moon B to complete an orbit?

  The planet Jupiter ijzf3h5 fw :ng0s $7.78 \times 10^{11} \; m$ 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 Jupiteeh 53pv284) gzrsijep r 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (g ip vsrj52ep3h 8e4z)The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)