Is it possible for an object myt )8.6a zks in+rw.unoving with a constant speed to accelerate? Explair6.. 8ksna)yzwun+ tin.

  Consider a particle moving with constant speed such that its agf:/pqpik-0p9 + vznehjft- u 3a3 h6mcceleration of constant magnitude is iqv- h3+ 3-6pk0pj fu:hfz /eptngam9 always perpendicular to its velocity.

  An object moves in a circular path at a con; 3f4vn, xl varil14d)8p ltmxstant speed. Compare the direction of the ob4)rxtnx ,vai d4lmlp8vl1 f3;ject's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of thunk o eyj6+e(1e acceleratiuk (6 njeo1+eyon is

  Consider a particle moving with constant4l*, b: hw6md2q.3 wuegcjgwm speed such that its acceleration of constant magnid,cg : 2mwelug .wm3 w6qj4b*htude is always perpendicular to its velocity.

  What type of acceleration fcridmk15em - 9x 2zy0does an object moving with constant speed in a circular path experien21c9m -xmeyfr zi 5dk0ce?

  What force is needed to make an object move in a/etl 4-x lbok1ev80d5 ht 2arp circle?

  When an object experie:xn )ifv au58snces uniform circular motion, the direction of the net forcxvu8s:iafn5 ) e is

  A roller coaster car is on a track that forms a circular loop in the vertical aokky:64c 9* ahvapi71gp4s splane.sp1y*7v a:pgkkao49ic ha6s 4 If the car 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 fos qpvz d hra:i:9qr065rms 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, what9: qha: rv6is05rd zqp is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a sq1m bl r+.5baxxsn g9)emi-circular arc until it is going straight) sl5+xaqr1nxb.m9 bg 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 curvelscbym r; 5qi s;:l--z of radius $r$ 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 cz.5do; fub fwog)r6pu ;2dlx4b6 / gf9sdz9fv. Then it goes around the same curve at half of the original speed. What is the centripetal for;o g 59sfbgfdczf2u o6r.)l9f4dbd;/u pwz6xce on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a cuh +pz-a,vcjx :rve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2vj -pzxc: vah,+. 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 of0v13pk s.l.9nuf ixpu radius r with speed 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 k pu.f9unil 0vps3.1xis equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, k;k4,e zpz8d6anzqgn4ee 2(m but one has twice the 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 laegkekqen,n( m48pzd zz6a;4 2rger radius curve?

  The banking angle in a turn on the Olympic bobsled track is nr u ndbc5,6:ldot constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of thn6ducrl 5b:, de turn. Why do they do this?

  Is it possible for an object moving around a circular pat)d4 i1 m. oxt7,zhci1wrr 56dd,arkmah to have both centripetal and tangential ch4rtwi od ,6 ar1mrm7azd1.) i xk,d5acceleration?

  The gravitational force between two objects is:4bm uix5l ex; proportional to

  The gravitational fo:*adpq/c1e 04 ptsbwkrce between two objects is inversely proportional to

  Two objects attract each othec;x 2(g bmxf,vr gravitationally. If the distance between their centers is cut in( xbfmx ,gvc;2 half, the gravitational force

  Two objects, with mas iszy.f2c- 4z p.rcydy4u/ncrv 2g w:yc08uh3ses $m_{1}$ 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 qiyl o8b3;i. o$m_{1}$ 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 ofx *k5pl y,itl9fi+a tps:9z h; universal gravitation.

  Compared to its mass on the Earth, the mass of an object onw.hp 9fl)ajy9lwwu4 7 the Moon is

  The acceleration of gravity on the M;co(*upd:wq* onlthge d-;nw )u62h k oon is one-sixth what it is on Earth. An object of maswd)c;pgdqkt ulnw -h2h:e; o(n *o6*us
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's sug+j3hdskb7: -o + w3cx:uw ,smk(twegrface, the rocket's weight

  A spaceship is traveling to the Moon. At what p:9,gbx ;p9r :8vnr0mzmojf*j4 an jj woint is it beyond the pull of Eart :n4 9j :m orjbvjfxa9*wg8mpr,0j;nz h's gravity?

  Suppose a satellite were orbiting the Earth * qaapla0i1. 0eyj4l.l9i xpsjust above the surface. What is its ceypla0px4sq 09ll . 1ia ie.ja*ntripetal acceleration?

  A hypothetical planet has a mass of half that of the Eart 5o(tz7+ag0cj .vazxch and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in ter(0gva+ tcc57 o.j xazzms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth whh ecl20ukc t,1at it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moonktu2cl 0h1,ce's mass compared to the Earth's?

  Two planets have the same surface gravity, b t7*6j. 1xyeotlec4wrm 4 r,teut planet B has twice the radius of planet A. If planet.l41j7e *e,4e6c tytotr mx rw A has mass m, what is the mass of planet B?

  Two planets have the same surface gravi73vv*mtroh:ybrc x 2s pi 795bty, but planet B has twice the mass of planet A. If planet A has radius r, what is the rad9pbi*r7t cb7 32 r5v: hoysvmxius of planet B?

  Consider a small satellite movin+co/xls6 t z9vg in a circular orbit (radius r) about a spherical planet (mass M). Whichstl6xo z9/v c+ expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satel xuh(q5ze.67f ft7om wlite B, and rotates in the same orbit. Compare the t7hx (fu57zmfo q6.we two satellite's speeds.

  A person is standing on a scale in an elevator acceleo8ogzhz r5 781jp, gforating downward. Compare the reading on the scale to the per7 ghrzo18z ,8j5ogpf oson's true weight.

  Who was the first person to realize that the planets mov(b-; 8enae vere in elliptical paths aroundee e(nbrv8-; a the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around thzrl b6)u7c7 ty/q0nvt;wf 21vil* lqpe Sun,nvul)pllt0cq frq z1 v7y2wib / t7;*6

  Let the average orbital radius of a planet be R. Let the orbital 43:ecy 7k,zrz yqf ,clperiod be T. What quantity is constanf34cz : ,yqzrc7eykl, t for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wixvqg5v491nr;a kv 6dsth 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 r v9xndvq5gs 1v;rk64a evolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun hxgny6 7 lsxfc 1nn bq9iss5yzx5* ++.is defined as one "astronomical unit" (AU). An asteroid orbity1s7 gnl9z+hxn5.5x sxnysc* b+ qfi6s the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.q/(z wurw5/dzbms,izt0h , 9p

  List the four fundamental forces i*( wr9nlr5cnf jo1 j*pn nature.

  An object moves with a constant speed of 30 m/s on46vl9yd vy0ggj4m, ip a circular track of radius 150 m. What is the accele 0y946vl4jd,pvyg ig mration of the object?

  The maximum speed arounds5z bj 0swb5+r a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all oth zbrs5s+bw 5j0er factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycleh36(mr vv 5g8rz dx)(1gbvhx m wheel rhbzh38g6dv vv1 x(()g 5 xmrmof diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locateddcfc1voaf /,l p0y4,s 0.200 m from the axis. What is the yvdpfl0o,caf1 ,s4c/ centripetal acceleration?

  How many revolutions per minute must a circular, rotating spac qi*9x:meuj h pkfs8t 2*./sxce station of radius 100ikjx q/m sh x.t9:f2** uces8p0 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 al rwz.n+se,bt3v f2 ia(o6:d9w6go zrt 96.5 km/h. What is the centri wsf3+v6.(,ol azg wr:zd ren b26o9tipetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. T*idskwh6d 86 fny;0rm he system is whirled i*sfiwr k 6y6d;dn0mh8 n a 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 attached to a strong string and whirled in a vertic3 7s v;lnce mw2oa01dbal circle of r0s 73w ;bndeval2omc 1adius 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 whirdo-mbwbq s+zu-/ : 4ivled in a vertical circle of radius r. At the exact bottom of the path the tension in th/mqb-o : +4 biv-wdszue 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 acceleratilrw0jsjv(/ gc :7z/mqon of 4g when pulling out of the dive. Whaz c:jsv/(j70mr l gq/wt is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is ben7 8p8s-gvrwie) .c 9+l ettvgyeath 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 weigiw 8s. ygrecp8v- lt +)ev9t7ght. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. fp0 f wq wes;6mgt*1g8 What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can sqpg 01w6f8t;w*e gfmtolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m rim/; 3/:rjk oxlwt5iuadius 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 c i5t:uw3xjior/l; /mkoefficient 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 t5 u5 l0atecz 6rvh yt8y9t9f8m/s. The centripetal for tfut0z5ta8y 56vych9 tre9l8 ce 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 t84lwg9p+ yj eof 14 m/s. What must be the minimum coef 4jwp+9egtl8y ficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v79niyl fu5cvpq oxk-8 -d ,ti2 around a level curve. The coefficient of friction between the tires and the iu5-n-t2ly fdpc7o89,k i xvq 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 required for an Olycs)52 sy ihyy5mpic bobsled to negotiate a 100-m radius tuyshics52y )y 5rn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled runp 8+sd y.ea/xj3;lhcr 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 of radius 100 m, banked eq*eww3k:e x0x l8z* gon-c5dat an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m bja)gc3j53+b fs+ maxis 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 rev gue6t8 oaa;4ju75vt nolving uniformly in a horizontal circle of ra8uon ju5tea7a tv46 ;gdius 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 ratk 6hr7tk/aa)ce car accelerates at a uniform rate to a speed of 45 m/s in 15tkkt67/)r haa 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 prx8n74d+ u l+g df-m4wndzetx5 oton 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 Ea hf)*0/kgf,.ix 2qk jv5iyuz e4al s6crth, due to the M a gv2zef )kcs/ j6 fh.5yl,iq0x*k4iuoon? The mass of 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 between t9*2ar wy,xx7lj1kky9ilno5 v;og7x fwo masses is F. If the masses are moved to half of their initial distance, what is the gravitational7;7 lok5 2ly99x xg rkn*wf yvja,x1oi attractive force?

  For a spacecraft going from the Earth t x8;un0)wp) f+gf+uax vumra,oward the Sun, at what distance from the Earth will the g+u, ffgxp x) ru0n8aavu);wm+ravitational forces 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 pkjc1:+ t e9xm1oau1ois $7.4 \times 10^{22} \; kg$ 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 distangl 9(*fg x4vzg638xob t e)nndce above the Earth equal to the rad x836bgt(e ngfng9zodl 4 )*xvius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's s)9d.xe bd2n3l+s 9p yp 6zscj g33wruhurface will the acceleration of gh3+3j9z2pws6ey x l3sbncu.)9rpddgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distancy 6s3i nxos9f6e above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, 9ino3xys s6f6is

  At a distance of 14000 km from some planet's center, the accelerationjtmg j* c0;,oc.rvyw7 of gravity is tj 0gr ;yom7cwvjc ,*.$32 \; m/s^2$. 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:56s4h x6mboub fwlf2 Earth has radius r. If the object is bsuf m2 5bf46:lowx6hraised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weig .im1i e7(hqj: psg.zuht of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of t1szih:ipj .q7m .(egu he Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r abovej:is (n6 sz.h)q62phsmcpv; q the Earth's surface. What is the satellite's h s:;v6m( p czjiqqp. s)shn62weight?

  A spherically symmetric planet has four times the Earth's mass and b:e no.mp.ca0twice its radius. If a jar of peanut butter weighs 12 N on thenc bpmao: .e.0 surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun ao/:u cbf*pls5zz./wz ll lie on the same line, with the Earth between the Moonpcf zs/ ul.w/z:*bz5o 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 to9ztvo9uu 08- :vsakpk 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 Earuwso i*qj6j1gcbc(m 5w+ 2 n5xth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (T6ius n5g +bwjccxo5j q21( *mwhe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aboutahwc4l w 1(y4l the Earth (i.e., it just skims the surface of the Earth)(14lwwah 4y cl. How long does it take to make one 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 suh/w43ezod8mk/ d 9v6an nz ea;rface of the Earth. It is observed to have a period of 89 min.h89o d;ne6dz vkme/4n3 / zawa What 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 asr3xlg l6xf7)n 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 Jupiwpf w 7.wi6ojoor(h32 ter 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 orbital radius 0 c4 *trsavski*w8:rxr, and moon B has ors wr0s*ci:48 *xat kvrbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is v-u * /wmf xb kh3lsjelnt0 b,/0;m;if$7.78 \times 10^{11} \; m$ 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. Whjd hoqe (8v38i*dt/ qz0 oy0poat is the average distance from Jupiter 3/qq *p o 8j8e0di0ohzvydo(tto the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)