Is it possible for an object movin1 .jtz;+me,djxx7h ndg with a constant speed to accelerate? Explain.hjz d 7d;jnmxt.x1+e,

  Consider a particle moving with constant speed sucvt2)9u-e ga ygh that its acceleration of constant magnitude is always perpendicugu)2ge 9a t-vylar to its velocity.

  An object moves in a circular path at a constmrl* z*-*afwdant speed. Compare the direction of the obje-f*rla**mw d zct's velocity and acceleration vectors.

  When an object experiences unia;0.ro md r+zwform circular motion, the direction of the acceleratioozrd0. m+w; arn is

  Consider a particle mov3hxuo p3qy31n va-xy7xmh j133n-g zf ing with constant speed such that its acceleration of constant magnitude is always perpendicular to its velocjgx1y3 z3nxxp- ho 73hv y- 1fm33uanqity.

  What type of acceleration does an object moving with constaa3zzir 58rb 5pnt speed in a circular r az83z5irb5p path experience?

  What force is needed to make an object move i9 epc9zuqx k),n a circle?

  When an object experiences uniform circular motion, the directi3bm n52a-iqu uon of the net force5 -u2aq3m nubi is

  A roller coaster car is on a track that forms 907-g.b zvm* 5ozuzo+9xntj ijdwb y5a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is by-+zv7gwbmdiz9juxn0*z9 5 jtoo 5. the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass -ainoqzd/d(c(k:p tzk i2 ;2f= M) is on a track that forms a circular loop (radius z(dcdq n( 2tfk2/i a-:p zkoi;= 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 point?

  A pilot executes a vertical dive then follows a semi-circular arc until ieg a l706wgu,it is going straight up. Just as the plane is at gaeg,iluw0 76its 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 radius m-fbnvdc 4od/+ fj4,n $r$ 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 spee e:bdt7nn1;)1gdenx kd 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 thede1:x1nnb )ngd; 7t ke 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 ar ir: fe:5+ug blgorq3( 4m7h(pl )ypcwound a curve of radius7qlmeg)yc:+rp g w i(3f 45l:hpu(bor 2r at speed 2v. 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 of radius r with speed v. If the roa gd rlrl6/v0t:d is frictionless due to ice, the car can still negotiate the curve if the horizonlr: d06tgvlr /tal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsledx- 3mw 9d ol)csonw- s(7tovh3oc)8sh 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 run) for the smaller radius curve is v. What is the safe speed on the larg38o c)wo)st xcv7h -hsm9wo3d-s(lno er radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant n )qro*3 eum7c9-qgqa, but increases upg9qc nrquo m3)a-eq *7ward 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 object moving around ak.13ssav-aj)vg:b6 vm.* rfc+h jbbf circular path to have both centripeta:f. a+v b 63)hajfjkms* gcbrb-vsv1.l and tangential acceleration?

  The gravitational force beefjp n*l3v8q5tween two objects is proportional to

  The gravitational force between two objx4lsvhxs) ,jo* bly-) ects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their o)5uezcm5 ;ut tom;(k centers is cut in half, the tou5c )5 (; mo;kuzetmgravitational force

  Two objects, with mash z a8;exnt)a,ses $m_{1}$ 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+w6aaw67 4 mc 0htefqces $m_{1}$ 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 univgv2y-zuer.. u ersal gravitation.

  Compared to its mass on theds+4 6o7ti, f/hjnqmldh3*sk Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it pnk;njs1ue*s 6 gq zonhc5d ays3z.j a2-,8/eis on Earth. An object of 5,z3ek/1pacas; o2djsnqhy8*6u g n e znjs.-mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the r: gehmor,n6 h ;eq31eoocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond kyiib*)6i0sr the pull of Earth's gii)ri0ysk 6* bravity?

  Suppose a satellite were orbiting the Earth just above the surface. What is (dj7bhv3lx3p itsd3bj hl3(7vpx centripetal acceleration?

  A hypothetical planet has a m-t8a )tojqi6* *mchijass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to grat ijo ic*-j)*hq8t6a mvity at the Earth?

  The acceleration of gra j(s;gn1e vmg5vity on the Moon is one-sixth what it is on Earth. The radius of thee1j;5v mg(ns g 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 twic i ;rtcpw+me-3e the radius of planet A. If planet A has mass m, what is theci +ter;-m3pw mass of planet B?

  Two planets have the same surface gravity, but planet By hj:pqzuc a94g:nq- ,cg:2j(be1 lqn rgq0x: has twice the mass of planet A.g:q,hu2by4c zn:exa -:cg 1qqjjrl0(9:n pqg If planet A has radius r, what is the radius of planet B?

  Consider a small satellite movu)ncyt s1dmw2iy(9 91sqf/ jj ing in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellni(yyc 1s)921j9 tfmj/q wsdu ite's orbital velocity?

  Satellite A has twice the mass of satellitvv v;*69kawxqt4w-rw e B, and rotates in the same orbit. Compare vkw;-69vwra4w t*vq x the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating down oos vmbp(y:x;+3ipect3 w h64ward. Compare the reading on : (4ow 3p+bcp y3ivo6 ;mexshtthe scale to the person's true weight.

  Who was the first person to realize tib pz,dc3tf xp 7g;3s5hat the planets move in elliptical paths arb;tz,fg is3xd7p3pc5 ound the Sun?

  The speed of Halley's Comet, while traveling in its u)1b(sqi ;3p : wuntabelliptical orbit around the Sub1us;nua3 pqib ) (w:tn,

  Let the average orbital radius of a planet be R. Let the orbital periwwiv3ctr50 +qx42amod 7n cf9q6* ygdod be T. What quantity is constant for all planetf4 dx3q *y9ia60gd+cnowwrv 52 qmtc7s orbiting the Sun?

  A planet is discovered to orbi p +( gqtirq/q4por-e4t around a star in the galaxy Andromeda, with the sqei4q p4+t rg (rq/-poame 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 that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomicp) ae).y 5n s o(k0mtii75eudlal unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun 7 )(mak.i en50doylitpu)s5e?

State Kepler's laws. g;; crznh1y:l

  List the four fundamental fozpl d2x gogzw :n0-xf;/*v9c arces in nature.

  An object moves with a constant speed of 30 m/s on a circ n4o- ss4lw +yu):pggfular track of radius 150 m. What is the accgo 4l)npusg :ws-+y4 feleration of the object?

  The maximum speed around a level curve is 30.0 kmo1gut3q 7vj 54m/5hxqgivi / m/h. What is the maximum speed around a curve with twictqv 3hujm45/gi i1gmqv 75ox/e the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a , 80qo3wixdva47 hzhtpoint on the perimeter of a bicycle wheel of diameter 70 cm when the bo 3dv08ih7wt4qax, hzike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the .vr,be8 l5v 1r3w dfpvaxis. What is the centvw v5 ev1d, b.8rl3rpfripetal acceleration?

  How many revolutions per minute must a circular, rotattvs oq4mww( u k ,m.//dv:n*oding space station of radius 1000 m rotate to produce an artifi /m(.vwdo4,ds *vtqwm:kno/ ucial 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 96.ih6:li8wfcvqx2on 5k 0gz6.i5 km/h. What is the centripetal force on the motorc 6q 5ciwi8gvkn2.6 0:ofh xzliycle?

  A 0.50-kg mass is attached to the end of a 1.0-m *8fynzg7t/.el0y kri string. The system is whirled in a horizontal circular path. If the maximum tension that the string8yr /*enl7ik 0fy.gzt 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 stro :0.y5i8min z-ps; p vdf;gvufng 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 the stone's weight.s-p;dnvm5; :fg ufzi0yp. i8v 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 ci hz dnjf8q3w5+rcle of radius r. At the exact bottom of the path the tension in the string is 3+hd8w3jqn z5 f 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 whe(k9)kumd94-wn4zc y1 nrkknvn pulling out of the dive. What is the radiu9y9 nwudvkz)- kc (44kmk nrn1s of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center gbjs5/xrwog r9 0oh *f*v-+a oof the loop is beneath him) of radius 3200 m. At the top of his loop he is pushihr aob x/*go-g jo0s9+wrv f5*ng 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 sevepd8h u 3g;rvl4n times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a sprg 8u;ldv4h3p eed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tirm- ; ;r3mtraytes on the verge of slipp 3ym ra-m;t;tring. 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 aiumd ck (h;1gpt gs7x *q+:ym2 flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided g ;ch gutiq7mk+ x2dp:ys(m1 *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. What must 6nccb cjw ,530(rkotf be the minimum coefficient of3cc n, 6 frbwk0tjc(5o friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. e0t j+i-sv cyno8;fspw.k6o9 The coefficient of friction between t+ts0wesi c-k ;jfn .9p86oyvohe tires and 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 re/z3 wz8,kwcy t+a-o9v8i1 b tpgljh a1o,dy w*quired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skiddi8dj3v, /1 wy,8wy cai-+wtgk1taob ozzp*9lh ng? (Ignore friction.)

  A horizontal curve on a bobsled run is banked aptany du*uqz ub +j1( (92cnb;t 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 ysf1z sdf-k,tz0+xxt 8)si o70p3 vqdof 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 banked n2 7,2(nju/qze18otia p(i mu ssvkd w 2z0xz5at $45^{\circ}$. 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 strinhsi u6* )9p w6o,gygshg is revolving uniformly in a horizontal circle of radius 0.ghh o6)6*i s,gs9 uypw500
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 h,ymn8v2 dd* 4g4 hfqacar accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill inqfgh2a dh*4,v nmy 8d4 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 proto ; uu((:tt95cx d,sgf kb d7lig78bhu, khwx/on 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 gravitationalo+rac v cdv c- hhk.2d0elu5r+5 ed29u force on a 70-kg person standing on the Earth, due to the Moon? -2uchr+0e5 clch v du9k+ed5 2aovrd. 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 two masses is mg lzg)au z3s4c, (a,vF. If the masses are moved to half of their initial distance, what is ,lu as4zg vz(c,ag3m )the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what 6-(csx)ltc9gv svk7qzr lf24distance from the Earth will the gravitational forces due to the Sun andc-fx(r st ksl9 v vq4gl7c)62z 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 is0f2 - wjphswt) $7.4 \times 10^{22} \; kg$ 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 distancqevjlb0uh.u dy h (. jquh:7k8a0s0 6ue above the Earth equal to the(d .60lv7kushuyj : ue .aqq0j0u8bhh radius of the Earth. What is her acceleration due to gravity?

  The radius of the Eapbpy a h;pk3+e;b)c 8rrth is R. At what distance above the Earth's surface will the acceleration o3h)p;p+8 aypk; c bberf gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance ajf-ucupe ,29ibove its surface equal to 3 times the radius of Mars. The ap29ifu-e c,uj cceleration 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 planeadmh lfy,z:3r3y *wj/t's center, the acceleration of gravity is* wyrj fzyld,3/ ham:3 $32 \; m/s^2$. 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 Ehvxw,0p7dm 0xu9bwpgwq9d7 te 1ol: )arth. The Earth has radius r. If the object is raised to a heigh)pxgw9t,d9u1 vbw 7xql0 oe70h p:mwdt of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight o dhjpb2n/oz*n 4m/vo7 f a 100-kg person change when he goes from sea level to an altitude of 500bpd/2 zmvoo 4jh*/ nn70 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above9 os+s pghe, i;vr0q,hi .yce* the Earth's surface. What is the saty+.ph,re9gi ivc qe*s sho 0,;ellite's weight?

  A spherically symmetric pl7i.. bpavxs: fanet has 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 wouldp . s.fxaib:v7 it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the samezm:+0uo g7zyl4bt5l t line, with the Earth between the Moon and the Sun. The Moon has a maz5u:m olt04+zy 7gt blss 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 transportezfhj+ cng7q) 1hy;y; fd 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 orbit about;r4bmvad2wx) 7no 9 pev of1f3 the Earth (i.e., it just skims the surface of the Earth). What is the speed of thedm ;97vfp b1)w n v3f4a2xeoor satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just)8*cpttnrt q:mr7teci67p6 wx hc 4v 3 skims the surface of the Earth). How long does it take to make one revolution around the Earth? (Te 6c8p6r c*m: vhwtq t4737)tp txnicrhe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in ci9crvnd l o;-2;plkcc/x; fqm-rcular orbit 230 km above the surface of the Earth. It is observed to have a period of-k mcc/-;l9rv2lp; xc q; ondf 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 Jupiter, has anei , q 3f22ve7dyfkm9hw-4u gt 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 orbits the planet with a radius ofbq6 3pcisxon n cr;q(z:c:is044upo2 $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly cirva*u-yr ;yw:2ey, ieb cular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete*;v2e -eyiy :wyur ,ab an orbit?

  The planet Jupiter is wkj9m1b jdg 2x .*ti rj2v8*jf$7.78 \times 10^{11} \; m$ 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:c(wb y9+ w5 agwey2hx4.vse f. What is the average distance from Jupiter to(w+hef s9by a5.gc4 y2:evxww the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)