Is it possible for an obje r4 i;7radh,b)nxe u4u ;ffg8xct moving with a constant speed to accelerate? Explain.duxr, hx8fane7ir ;f;) ub4g4

  Consider a particle moving with constant speed such that its 8;qlsje vbi*r-0 v(mwv um1*y acceleration of constant magnitude is always perpendicular to its v(*rjm*ivse1w8 ; v -q0vyumbl elocity.

  An object moves in a circular path at a constant speed. Compare the dirk,u ngtcb2fi9 *bzl m d62/)znection of the object's velocity and acceleration vectorsb2gt 6*9nzc,)bmn /uzld 2ikf.

  When an object experiences uniform circular motion, the direction of the accec4b )q4wr-8 bmwip x4xleratiocr w-pmx8wxb44b4 q)i n is

  Consider a particle moving with constant speed such that its acceleration o +ufo7 gd 4atcwk2q;n0q)6rcdf constant magnitude is alway2cun)ag4c rt+dw k0;dqf7 6oqs perpendicular to its velocity.

  What type of acceleratio yflt;4sc6ej5n does an object moving with constant speed in a circular payljetc 5 f;46sth experience?

  What force is needed to make an object2nr*b8nz 6(x sylcjb) move in a circle?

  When an object experiences uniform circular motion, the directimhrur2 akx /o;b:) km(,ae7 foon of the net force 7 )a,rume/;ma ok(2k rbx: fohis

  A roller coaster car is on a trac a/p9yioy4ll3 ki5uq0 k that forms a circular loop 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 i09 luyi5k/qp4 yiola3ts centripetal acceleration at this point?

  A roller coaster car (yja 1fici, )1/q(me usmass = M) is on a track that forms 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, what is the minimum value for its speed at that point1ajfi( ,s/i cue)my1q?

  A pilot executes a vertical dive then follows a semi-circulh, rm1aj/ wxw-app )a)ar arc until it is going straight upj) xham1w rw)a, -a/pp. 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 radiu7u;sa s-oh s1mgs 0q+f3nadq3s $r$ 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 goes aro ,v+28bgsiyf/ac 88.xd) o 4inmsr fyeund the same curve at half of the original speed. What is the centripetal force on the car as i2s8o nxcy y 4m.,)8g iebrfsd+/aivf8 t goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goes arouq/ctz n1hm b0)5o4 .nwi;def6db8e qhnd a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, comp 1nqh6cei tdo)bm8dw5;z0./ b4ehfnqared to the first?

  A car of mass m goes around a banked c 0x(ickdr t-)t7 q,wgwurve of 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 for)c 0kt 7t- dw(wgq,xirce on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same acep )zc90fxnnev3f- x6q5x+ xngle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius -9 x nxe5c qfx3+ 0venfzpc6)xcurve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on tcaz 9+z : gp3nb,wjhs*he Olympic bobsled track is not constant, but inc p*hbz9gna3:w+zc ,sj reases upward from the 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 obj*u amjyo hodb /1x92; mqd0k8hect moving around a circular path to have both centripetal an mddohoju*h 192 xby0q8kam/; d tangential acceleration?

  The gravitational force between two objects is proportional t6s dshe*.lmkkwmw9m4 5,m 1yuo

  The gravitational force between two objects is inverse /9dzsf; d+d6u4dxb hyly proportional to

  Two objects attract each other gravitationally. (bu:0d 5xdxv aIf the distance between their centers is cut in half, the gravitat:d d vx0bxau(5ional force

  Two objects, with mayb y2dtq6 4) tjt8c;;g ti )tctv/tlw)sses $m_{1}$ 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 eo511b ll9bit $m_{1}$ 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 univecke.0 o;4qb;;y;6rsul0: ov plky fhorsal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Mglq)a8s1efj:(w wq k ;oon is

  The acceleration of gravity on the Moon is one-sixth what it is on Ear wn-.-ufx jjg1th. An object of uf1xj j.gn-w-mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weightn mitaj)jm9;3: 4 yhfi

  A spaceship is traveling to the Moon. Atub.zn. gi1vy 6 what point is it beyond the pull of Earth's g n1zb.g6uyv.iravity?

  Suppose a satellite were orbiting the Earth justa: /axe x,: zfwgoi2y; above the surface. What is its centripetal acceleratio,o2ig; a ywa x/e:xf:zn?

  A hypothetical planet has a mass of hal jsf4 : ax*c,i :y .ckbznb1fqrb)j96cf that of the Earth and a radius of twice th:c19*) jfc4, .:kzn6 b jqifrbyaxscb at of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravik2 ivic;x2*kjbe,8is ty on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth'sj8e*b;ki xiikv 2cs,2?

  Two planets have the same surface gravity, but planet B9z(q pqcw9 p4f in7u3q has twice the radius of planet A. If plqcuw(9 q ipf pq47nz39anet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice t/arms9:;3nmx uxnl b *he mass of planet A. If planet A has radius r, what is thexrm a/3;nn 9xm*s:lbu radius of planet B?

  Consider a small sateir e6zjko ,o6nx*1b j4llite moving in a circular orbit (radius r) about a spherical planet (mass M). Which express66,bjio1jkr4znex o *ion gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, andfk9gvxj+h o1 4xzf.ekz8 :qv 4 rotates in the same orbit. Compare the two sx4. vj :x +fh1zv8qko9gz4fk eatellite's speeds.

  A person is standing on a scale in an elevapx5k n6l:: huutor accelerating downward. Compare the reading on the scale to thh5un:x:u 6lk pe person's true weight.

  Who was the first person to realize that the planet f:6hbop tm7gj ,q8 kzfe:/f:ss move in elliptical paths arpz::hjbs 7 k,o8/:fm f6qtfeg ound the Sun?

  The speed of Halley's Comet, while trave l*br;1en)oppfd .* ovling in its elliptical orbit around the 1 )prvl;.do on*e*fp bSun,

  Let the average orbital radius of a planet be R. Let the orbital periokn.v6 ytx a/(zd be T. What quantity is constant for a. vy /znktx(a6ll planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galki5d7lsywpnwk )w(1 p; oheaa* ;b8y *axy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 tia(1ei8lw5pyy*nw;dhk7p s o) wa bk*;mes 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 as one 2*f8bq ;shdgfly 06ae"astronomical unit" (AU). An asteroid orbits the Sun in one-third of a yea h*ff;28ldy 6q0geabsr. What is the asteroid's average distance from the Sun?

State Kepler's laws.yi 0lahk,cq x2bgs i.+ea,, :c

  List the four fundamental forcesypn1)ugw3wra ly 2 i*o9l35w r in nature.

  An object moves with a constant speed of 30 m/s on a circular track u/l 4.yqmjvr se3roh- -7 wc8kof radius 150 m. What is the acceleration of the .8 r 3/lwqyo mu4-crh7ejkvs-object?

  The maximum speed around a level curve is 30.0 km/h. Whukqs.nsfv2f3 3 8d2iccc 9 g-oat is the maximum speed around a curve with twice ts2k3 qd3on9cv fc 8fs-ui .2cghe radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle pp(f s1b88 jq*u/qokg wheel of diameter 70 cm when the bikegqjb *(8u /s81 oppqkf is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ax/oqxmi6pgic:+ay yoq t 9ba*jhs3,* )is. What iscbqa3yo/iy t qoh,*m 69ispg +)x:*aj the centripetal acceleration?

  How many revolutions per min cc3 vt,i(61mkfh (1iparjgx )ute must a circular, rotating space station of radius 1000 m rotate to produce an artific,fjxt mrg c 3a(kvp)ih(i1 16cial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius y20.thyf0 i5nvgm 5znturn at 96.5 k5 ymf.h y5iz0vtn0gn2m/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. 42y6g/iz vyy7 v,dp few(yci 6The system is whirled in a(wc4yp6e fiz ,v2dyyivg6 7 y/ 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 vewl7,aw j7k7q 3j f*;ncmpl;vfrtical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone'q, ;vlkncf3pfj7 ;wwj77 l*ams weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a ,ry u4:x+n 2kvfye (+lbrl z0bstrong string and whirled in a vertical circle of rab2(l4xrlr+0v f enyyz,+: ukbdius r. At the 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 acceleration of 4g when pulling out -acgh3crp b6ootju1k9 f5f02:r j .ju of the dive. What is the radius of cufbt 3p5g-r ocrj6 uoj0uk:f. 9h a12jcrvature of the loop in which the plane is flying?

  A pilot makes an outoddxqa/ .2uvb6k8y u-side vertical loop (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 one-half of his normal weight. How fast is he goinguk28q oa.yu/6vdx - bd?

  The maximum force a pilot canpej.voor-isy( .6ig + stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot,jisi e6-oy. v(+g.op r 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 horizon nae7rjs-r isa u,d3+pvg ze2h (*1*a7)gla wdtal curve with the tires on the verge of slera7p daga *das2g )3ue1wh rv,j*+7izn-(slipping. How fast can this car round 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 withex d o)8p 585fw1uhxleo7 vlh- a speed of 20 m/s. The centripetal forcee8f e17xxdl hul5v8owo5 )ph- 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 rzhdg(55 i fe0a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road ffe0ih r5zg(5dor the car to make the turn?

  A car is moving with a constant speed v around db j4x31k 1xarxh.nd2r7 f2pna level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the cudrxjbrh2 xfk21.p x13 a74nd nrve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled t9f9qfqd ,b:s co negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friction.d9 9scb,qfq f:)

  A horizontal curve on a bobsled z wln ;1//)psp4hwuhg-ac7yk xx c0*yrun 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 at an al inq g m.2swx9cw2;c2ngle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 joy3ki/uy gr05, 4si0ls a)a jm is 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 s(3xwo0 .bgf 4pmno ki l.7/wxltring is revolving uniformly in a horizontal circle of ra i 3x0kf.lgxlon4p.mww7bo /(dius 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 px -l23n:jzodp it area, a race car accelerates at a uniform rate to a spejodz :p3x-nl 2ed of 45 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 mas0ja4 0hdgh +zes $1.67 \times 10^{-27} \; kg$ 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 ljbp9i2w abna*cr+4eb 4- lyix ;5jh070-kg person standing on the Earth, due to the Moon? Thea;p 0xhi29n wyj4b4lj5b c*+i brlae- 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 forcenwof807+wrv- xlc6 hv between two masses is F. If the masses are moved to half of their initial d cr vhf07owv8 xw6ln+-istance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at wvdlikaf/o. ul x1q+ 04hat distance from the Earth will t.1vok4dlfl+i x/0u aqhe gravitational 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 istz6h8xuy/) o1l gl 57 uwl8h nr7)xjxl $7.4 \times 10^{22} \; kg$ 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 * 0t4sxsn35 gzjn6 ahb3i7h hjthe Earth equal to the radius of the Earth. What is her acceleration due to gg4ns5z0inhas j*6jb 3h x th37ravity?

  The radius of the Eartyz,z. ghtpu. :h is R. At what distance above the Earth's surface will the acce,.h y: ztu.gpzleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a c3jgz/; j) jfbv b(g)hdistance 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 ; cbj (g)3vjzb/ f)hjgMars, is

  At a distance of 14000 km from some ult n4 w8;ubsb6n-c7h planet's center, the acceleration of gravity is 7;6 8-nu 4slwbhbt unc$32 \; m/s^2$. 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 Earth has .jf3bwf0 uc*dzp-xxnjxj+e6z 00 tz/ n,c)mxradius r. If the object is raised to a height of 3r above the Ex zm3 ctwc n 0dz0xjf0e*xx,n )6fzj bp+.uj/-arth's surface, what is its weight?

  By how many newtons does the weight of rdfs27c,wys4a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radiuscyfr4sd,2 w7 s of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of massi3wsu3 ;2l5wrvo c 0f)c5 ebez 100 kg is at a point 3r above the Earth's surface. What is the satellite's w)oz;3el uiv2s5erwb3 cc0f 5weight?

  A spherically symmetric planet has four times the Earth's mad(sm0a d5:)p i+ggpqv ss and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how pq:(ap id vds5g)mg0+much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun a fu0/ i:+mxo* zo2+xi rrr1zsnll lie on the same line, with the Earth between the Moon and the Sun. The Moon has riri/z*xx10mn 2 rf+oz u+s:o 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 to the Moon.u4y42bt :i alr
(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., it mfyoh/j- t w48just skims the surface of the Earth). What is the speed of the satellite? (The mean radi4t fj8/y-mohw us of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbin2z uf w+4u 7 9d,gcbqqupml-vv);2ptt 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? (Thuwu4ug92+) lmvdzt2n-pvcbp7,; q q fe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the sur37.ze19nzc2m ymlrsib w ;o8aface of the Earth. It is observed to have a period of 89 min. What is the mass of i1zwmlzs c3.ba7;2 n9ymo8erthe Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameta1vkc cu4g/tni 3* 8yqer 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 withka)wf4;e- nlh 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 plan6ji ; 1imw *qx;vehczx;-ny1 bet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to compin;-m x16bi qjx*v;wye zc;h1lete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 1zbp*upnjt3ejrg., , a u 0tdvrp0 *7u$7.78 \times 10^{11} \; m$ 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 x20 yxadzspi r,,l9b; tn(hhc68e j y-Sun once. What is the average di -hy9ndx,p r0h,jliex8 6;bzsta2c y(stance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)