Is it possible for an obje w)wn)dt,a uo(ct moving with a constant speed to accelerate? Explaia),)wunt d(o wn.

  Consider a particle moving with constant speed such that iter+6 ukqva5q+ s acceleration of constant magnitude is always perpendicular to its vel6 qu+kqr5+a veocity.

  An object moves in a circular path at a constant speed. qat-t. q: g9pd *xg2lhu(ybzf6wk;i6Compare the direction of the ofbgq6kt ;96 -*. w(l i:hygqztad up2xbject's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the dirfnwu2*hl 0*uk032ew mjygs2i ection of the acceleruh*wkf lg2 *0nj03e2umyis w2 ation is

  Consider a particle mov; q m g/4ofpbz;r2a)nying with constant speed such that its acceleration of constant magnitnm 4q;y g z2roafp/;b)ude is always perpendicular to its velocity.

  What type of acceleration does an objldc- 9kqej/yk,g ef:pwid:86ox1 l bd 9x2ge 2ect moving with constant speed in a circula 1dkj2gbf -,i kxll xeqed96o::y 2c8 gdwpe9/r path experience?

  What force is needed to make an object mov lm.a7y tu wiy+g xla*7of2m06e in a circle?

  When an object experiences uniform circular motion, the direction of the nukyt tal+( c. b(yn5u1et force ibt.kty1nu+ y( (lau5c s

  A roller coaster car is on a track that foe.q m9y8cvjk mxv2 1: ;egkoj.rms a circular loop in the vertical plane. If the car is to just m2 cg; :j1kk me9jv.yv8oeq.xmaintain 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 (maiiy 9pqie8j .r:nk6*kss = M) is on a track that forms a circular loop (radius = r) in.pkji 6i:*n 9e8qr kyi 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 followsudyc42xjlrr f045j (b a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him i2l4 4 b(f05xrjcuryj ds

  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 radiuccrd s ;l5t(7gs $r$ 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. Tmhmj o)/u0 6 ey0y+ w b8xogz0tfn)pe(hen it goes around the same curve at half of the originalyu( ehgp8+o0tb06xy)m0o/w )z mnef j speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radig+6( on quon,zus r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the (,n6qoo+n zgufirst?

  A car of mass m goes around a banked curve of radius r with speed v. t9f c,nm1fbi w(-en r7 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 is equal in magnitude tif9(wnn, -r1mtcf eb 7o

  Two horizontal curves on a bobsled run are banked at the same angle, but one has0pb.bc rslb0: oja :d8mzq5d7 twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius pr qcmsbadbz o.b0jl :d:7850 curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsp,e1fr/) qg, yi(uqgx led track is not constant, but increases upward from the horizon) y,i uepgqf1q(gx /,rtal. 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 6iz (tz5 ,wm lrdy/rq+path to have both centripetal andzi rq(6ydzl mt,5+wr/ tangential acceleration?

  The gravitational force ;i+rz a-ux1oaho e/+jbetween two objects is proportional to

  The gravitational force between two objects is inverselyg wrt 8k8e,rzt 8tp-4c+kxk*vdns8- w proportional to

  Two objects attract each other gravitationally. If the distance between theirp* rxsc 7tae co/a*62z centers is cut in half, the gravitational fo*ax6rec 72ot saz/c*prce

  Two objects, with massessjg jud)n03)j5t0hj3.8 n lwk rvlg :y $m_{1}$ 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 mas.exic6iru 5 kc0;.pu 5vomik5ses $m_{1}$ 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 7)kctihpg9 zqpu.i( .f universal gravitation.

  Compared to its mass on the rxzh tqy v/3un,+m3 my-l,p k5Earth, the mass of an object on the Moon is

  The acceleration of gravit,t.cc2sf+k jrw)nw w7 y on the Moon is one-sixth what it is on Earth. An obj.cw) rfs7tjkwn w2+,cect of 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 wepyehc-u7 0bk t0xo 7q9ight

  A spaceship is traveling to the Moon. At what point is it beyond thecz */8uuia w)g pull of Earth's g zc*/w) uai8guravity?

  Suppose a satellite were orbiting the Earth just above the surface. +(af rcl3y5 sp What is its centripetal acc(+5lrys3a pc feleration?

  A hypothetical planet has a mass of half that o.r z/+zmz r/vuf the Earth and a radius of twice that of the Earth. What is the acceleration due to gravitr/r vzzz /mu+.y on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the i:67vn3nk hlh 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 massn6h:ki 7 3lnhv compared to the Earth's?

  Two planets have the same surface gravity, fg w lx78 4l0c(iw/k:u4 rxxm9xmag*i but planet B has twice the radius of planet A. x7 c04wi(/x8g mkwm:l l4 xui9f*r gxa If planet A has mass m, what is the mass of planet B?

  Two planets have the sepe*ta9yax4l 6- c/w tame surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is th t/eay wa4-ex9tpl*6ce radius of planet B?

  Consider a small satellite moving in a circy;9rh59 j jy3pl it4lg0d7lqjular orbit (radius r) about a spherical planet (mass M). Which expression gives this satei9lyq5;47py dr3jgtljj 0l9 h llite's orbital velocity?

  Satellite A has twice the mas,nj s m m*2qif*tysv4)s of satellite B, and rotates in the same orbit. Compare thet s) 4s*qvni y*fmjm2, two satellite's speeds.

  A person is standing on a scale in an 0in hv bq ye hlwz88:7((qzu:pelevator accelerating downward. Compare t i7hhw(qe:8p0lz:n8 buzvqy(he reading on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elzl ols gv1blt+ 68/qb9liptical paths around the Sogb z vblll/1t8s9q +6un?

  The speed of Halley's Comet, while traveling in its ellipticalb v3,kn5r)(lc/gnz nmq cc;c 1bt/ *yq orbit around the blvz5/ r)kcg1cnc yb;nqmc3t( ,q/ *nSun,

  Let the average orbital radius of a planet be R. Let the orbital period be T.7 )ipmys q3w:6fz2wkd What quantity is constant for all planets orbit3mp7fz w)skid q:yw62ing the Sun?

  A planet is discovered to orbit around a star in the galaxy/udb95 yhif3 1 x d hblxfbc0.(r12byu Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has bu 9.2ycb bld5u1hff3hrxby0d ix1/( 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 deqwq35coyc2 7k761 hwzgkj,ch0* ml cpfined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's aveq o ckczhmww7c*k h351, q7cj26y0plgrage distance from the Sun?

State Kepler's laws..g3nar *oozx1

  List the four fundamenuya 4 tcqg-5au7sl)a.tal forces in nature.

  An object moves with a constant speed of 3g(+ /t)5h pv1zg;v jlin txb;u0 m/s on a circular track of radius 150 m. What is the accelera(vi; gv l+jxh;g/tuznp t )1b5tion of the object?

  The maximum speed around a level curve is 30.0 km/9cf5u6aimzh/ yvy *l jag4q4uy ); v6c e0*cwth. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchac4fzvayq * 5 *aymvc4t9yh;u6gwi)60lc e/ju nged.)

  What is the centripetal acceleration of a po+ 59dij,kvu uoqz)*w bint on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movingb ovdw5+jq 9kuu iz*,) 8.0 m/s?

  A point on a wheel rotatkx44d +ndpvx 9:nw6zg ing at 5.00 rev/s is located 0.200 m from the axis. What is the+zd:nw6vp4kx dg4xn9 centripetal acceleration?

  How many revolutions per minute must a circ44heby f(o,0nw z5ki7 moi6iuular, rotating space station of radius 1000 m rotate to produce an artificial gravity onh5ik6,74fimu o4bwi( oeyz 0 f $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn4 p ls wy iq-r;cou65z)sayw)3 at 96.5 km/h. What is the centypcs 6ouliar4 z5;ws-) y)qw3ripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whic9*a1mvf t+u t-4mc.x-wqf uj b2r.gy rled in 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 breakr-w bctq.-ym.2m4u1* 9fucj xgf+vta ?

  A stone, of mass m, is attached to a strong string and whlqn n9r2k jry;4lnj*cd5w*.q irled in a vertical circle of radius r. At the exact top of the path the4*jn2wk 9 l crrd* y;ql5n.qnj 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 st;gze cqkzuz.j.5: 1 apring and 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 speed at this pgazzk;q: 5u 1e.c. zjpoint is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g25ut tzrzyq o89izma tn* 55bhj3. pe/ when pulling out of the dive. What is the radius of curvature of the loopie55tp q 9r t8mz5.yzz3t2bno/ uj*h a in which the plane is flying?

  A pilot makes an outside vertical loop (in whic1mc 6 jypqx, 2q,t-8lqw5elqjh the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing do2qp1q,-8jc wq ymx ,lqletj56 wn on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pit)sq- 1x lc-9ad) c bimj4geo;lot can stand is about seven times his weight. What is the minimum rmb1ed ) )sc;-cxgja qil9-4toadius 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 roup hyjc9d 9mp2.+xo d:knds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume + :kxp9jdpd9yo .m2 chthe same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m wikq21/ p .w1ic4ylr aec/8hkko th a speed of 20 m/s. The centripetal force provided by friction is chc/a4 1.r2l/kkwioy 8qk e1p$1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a 91x u8u;vw,s7rl9bwcoa ck f;flat curve 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 fkob7c v s;wwrx18uc;l9 ,au f9or the car to make the turn?

  A car is moving with a constan30 fsp6lfw c qlld*h;8t speed v around a level curve. The coefficient of friction be fhl 0l*ds6l8pqcfw3;tween the 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 required for an Olympic bobsled to ne3mgth*ztrtw ;0 e)f 8pgotiate a 100) ehw38fgtzmp0*tt r;-m radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankem;;w 0t uvos:cd 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 of .c+n ,5,gsqu quouf8 z$45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is barc5av;8 y(sh c5v)grk ry /f ):.xsmcov-ynd9nked 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 revolving unif*:arg 2os+ ce3jbc+ dzormly in a horizontal circle odbsa* cejz:c 3 r+o2g+f radius 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 ar(p hivr/s- qt )bd/mb0::wghrea, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 mhhg i0 wp-trsq )/mv:b:(b/dr. (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 profn8o/ywl(gju p 1 a5yw9hv/2 wton 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 t(mr+n,/ e0 /xmmlnhs uhe Earth, due to the Moon? The mass of the Moon iss e/ lnmm x0(n/r+uhm, $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between tq9v)azhx ey+07j:1bjq tnaz -wo masses is F. If the masses are moved to half of their initial distance, what is the gravitationalq9yz t +1-)jb70aze nax:hvj q attractive force?

  For a spacecraft going from the Earth toward the Su6a (o: f) ljjuphw.je(n, at what distance from the Earth will the gravitational forces due to thee6aw.j(l) ufpojh( :j 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 is q hn*(a(3m qmw t4fc9w$7.4 \times 10^{22} \; kg$ 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 Earth * sc5jut7ud4 mequal to the radius of the Earth. What 7 s4ct5uduj* mis her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface wilui5ua(vt j6h igt3*n gbi3jl, 8zgw (0l the acceleration oftui(iz*v hg,ag 8b33(lw tin056ugjj gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dige a3 q4h/qg 0(9pzughstance above its surface equal to 3 times the radius of Mars. The acceleration of gravity ofgh /9agph4uz0q 3 (egq the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some p-t(2 m5dzy) sfg1z0e bhupo(f eu;o0planet's center, the acceleration of gravity p(tsyofgu- ;feez0m)b 0 h 5(u1dop2zis $32 \; m/s^2$. 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 radius r(* re hj,bzjf48n9 ufy. If the object is raised to a height of 3r above the Earth's surface, yu*bez4njf 8j 9h,(f rwhat is its weight?

  By how many newtons does the weight8t n4 pgtx0 + -,jh/sont6oqrq of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Ea t6ro8/qo4h np0+gsjtq n -,xtrth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 1002fhjo,qa7xw-udxa (;h7w) w z kg is at a point 3r above the Earth's surface. W j- how 7;hdw2,azw x(f)ua7qxhat is the satellite's weight?

  A spherically symmetric planet has four timeuiz kois3j:zb;*v3-tl gp.3ws the Earth's mass and twice its radius. If a jar of peanut butts3 -gu.:vi3oz jktib 3 ;l*wzper weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Mowewgk 01l sx-n5zse fh,y5gm v(bvq*d4pp(,.on, Earth, and Sun all lie on the same line, with the Earth betgvg.*1, (mn kww(s5,-s4zvbehpyl0qp f ex d 5ween the Moon 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 to the M+ db27je/wq8aueim v3oon.
(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 jg7 3uo0g7xa 3f;kobfcircular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean 7fobf3aj g0gx 7;3uko radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., i8 9p7ng +fxwlggq/9ta9dc zrnobu9/, t just skims the surface of the Earth). How long does it take to make one revolution ar nnuop9989gw9/zdrcb+7,fga/l tq xg ound the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230l1mx.p /w/f wbln/;:j cu ln+w km above the surface of the Earth. It is observed to have a periowb/u/l;fpwlw x/n ml. n1j+c: d 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 Jupiter, has an orbital diameter og v79ovvc3y36bm )wtt8tu zj(f $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbitsw9c0r3sky)5 yepftp108qy ub 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:9 0 o()pwkn.aomz mms nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How( nkwp) o0a9smomz:.m long does it take moon B to complete an orbit?

  The planet Jupiter is,t ve( 1-izk)cr;p.utm sixa3 l 7t:nt $7.78 \times 10^{11} \; m$ 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. What is the h 0xbh0/l k. bled,.dkaverage distance from Jupiter to the Sun? (The distance from the Earkblh.d0dxe/k 0 ,l .bhth to the Sun is $1.5 \times 10^{11} \; m$.)