Is it possible for an object moving with a constant speed w ).io:rrqgt6g9 m9wpto accelerate? Explai:i.9 o) 9gprwt 6gqmwrn.

  Consider a particle moving with constant speed such that its acceleration 7c8p7pdprx:myu1.y lu 22tdoof constant magnitude is always perpendicular to its velo2x 7d 1up.lcydpmu2:ytp7 8ro city.

  An object moves in a circular path at a constant speed. Compare the direction ork sf)5tii17h f the object's velok ift sh5ri)71city and acceleration vectors.

  When an object experiences uv+e*uo8o 8ppu z(i:gf niform circular motion, the direction of the acceleration (ueog p8: +ovfz8upi*is

  Consider a particle moving with constant speed such that its acceleratt3md 3 4y5cpyt87 7fmua xyd6eion of constant magnitude is always p mt74ype3 7m8d 5u yac6dfxy3terpendicular to its velocity.

  What type of acceleration does an obj.y3 0mlgayj .exkmgp/,ye.,p ect moving with constant speed in a circular pkp.ea../ylm,x 0g mj3eg,pyy ath experience?

  What force is needed to make an ob ;;jhh3)hiu rvject move in a circle?

  When an object experij wz w 0w,h4tsztpqa01/6tei,ences uniform circular motion, the direction of the net forw4w6,it0 zsz,jwte1qh 0a/tp ce is

  A roller coaster car is on a track that forms a circular loop in the vjg. ;k li3-byu x,po++9gsms:xthb,vertical plane. If the car is to just maintain contact with track at the top of the loop, what is tg-x+.s ;s vo tb,b9gy p:imljuk+3x,h he minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (raw;lwsjv i0hwa3oge (e57:tq rs2. q3ndius = 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 l0wi: ntvs (2se7eqahqw5g.r3 3ow ;j that point?

  A pilot executes a vertical dive then follows a semi-circular arc untrpdqxe r 7+jm 7lf;5 0.hujefoum( e42il it is going s2x7 feruulmd .0 j7e m5+rohe(fq;j4ptraight 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 radius wc deoh :+, +novw)ojy:s(ivg6v 7t/r$r$ 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 a6knd1w i s(hb) constant speed v. Then it goes aroun1wd)hki(6bns d 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 the first time?

  A car goes around a curve of radius r at esq s dkt7t46hzba -;ik+7 ku)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 thezae u k)-bi kkdsh6 ;7st+7qt4 first?

  A car of mass m goes around a banked curve of radius r with speed v. I1biajpz dmn/h3*jyj7w-56 oh f 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 jp1 om6yjjz ba-h5 d7n*iw/3 hmagnitude to

  Two horizontal curves on a bobsled run are banked at the s b r fx5y9uub5z2ssbw 9eg e,62e(ogi2ame 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 isuube bw9 2syo2riz56e9sg(gf5eb2x, 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, s4yvb .-g-q3-1nj 1tknzb2jvjj/os j:au5 vfbut increases 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-sq:jj3nv.gvn-bzja j5 k4sfv11/uj tb -2oy they do this?

  Is it possible for an obj5+g:;a ualqpe1 p3hu z yd4(paect moving around a circular path to have both centripetal and tangential accelera5pp +uapl( ughy43ez:;a qa1d tion?

  The gravitational force betwetdj+d o 4t+qhpc y2n5.en two objects is proportional to

  The gravitational force between two objects ixag w.cx :vxk2 5lu0lon89cxals h:13s inversely proportional to

  Two objects attract each other graviq 5 u6 aq7tbczo k5u581doazig *cwa+(tationally. If the distance between their centers is cuu7dubtz6+1(aqkoa5i zq*5 cc8wa 5got in half, the gravitational force

  Two objects, with massezx ff;zk63iu 9bwq1g vn m4b07tjd2j,s $m_{1}$ 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 mas3ag di*cm2 pr:ec5 x +xr, /k3hadby7-q8xmwgses $m_{1}$ 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;xs0l b y)hpb5ek+pv5 universal gravitation.

  Compared to its mass on thwv+d3hso1ix +x 6f 2fg9i/qmie Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixtluo04+pljp2k h what it is on Earth. An object ofk ou 0p4+j2lpl mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rock;tt9d.b* z(+fs b hjxw.mx 1lxet's weight

  A spaceship is traveling to the Moon. At whl97/buwsw q m4at point is it beyond the pull of Earth's gravi4w7b/9us m wqlty?

  Suppose a satellite were orbiting the Earth just abby()6v s018t rfmty c; chm0upove the surface. What is its centfc6 sy180h;pvu y0m()rtbm ctripetal acceleration?

  A hypothetical planet has a mass of ht7 *rihx(p z jy ,bn)ya09ral8alf that of the Earth and a radius of twice that of the Earth. What is the acceleration due to t 7a8zxib9hj* pn,)ya(r0r lygravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is xq(qy7p8i(y8 n+bbb; lrxhto/xh+ (u one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What h7h xb8buo 8 yy;tqixlnqp++(r(x/(b is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, buxji mj9i68j( jz c +j6fc3owl9t planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planej6+w6j3m9cozjjii9 cj ( 8xl ft B?

  Two planets have the same surface gravity, but planet B has twm7hghu4z;mdlc 6*+sa wd19k iice the mass of planet w g;7 h+ ksim6ldmazd19huc*4A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving bx5mo x 8 d 9yut+qz.grnuf;97in a circular orbit (radius r) about a spherical planet (mass M). Which expression givesmb9q7zg ;o5x.n+8rtd9 ufx yu this satellite's orbital velocity?

  Satellite A has twice thf qa14+wsj,zb e mass of satellite B, and rotates in the same orbit. Compa szbj,+w1f 4qare the two satellite's speeds.

  A person is standing on a scale in anhp-4ci2 wczlzi(pl ; / elevator accelerating downward. Compare the z;hic/ ip( 2-llc4zw preading on the scale to the person's true weight.

  Who was the first person to realize that thzom++zs q*6hf o 6k0fxe planets move in elliptical paths around the Sun?x66sfh z0 f+m qo*okz+

  The speed of Halley's C /md7- m00;t zpquxi4ku4eypxomet, while traveling in its elliptical orbit around the Sun,x04p4p iky;mqd/0xzteum7 u -

  Let the average orbital radius of a planet be R. Let the orbital period hcjvo3 zs43 pv7kd7u+ be T. What quantity is constantz4duovs 77hv+3kpjc 3 for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda;+e1vh i0krbe , with the same or be1kh+;e0 vribital 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 the5tmstp /9y; mi Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sum;tm9 sty5/pin?

State Kepler's laws. l*;yx4psdo;f6ue q j-

  List the four fundamental forces in nattqmmug 0gs;+l1njo.1 6i w4n hure.

  An object moves with an tc (kx*+8 :7i dqgv0fqmlz ng-fp9c*khv1 z9 constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the objectcgz i1:mdkv-*f0q(*q zg7nk 9l8c+hnpf xv 9 t?

  The maximum speed around a level curve is 30.0 km/h. What is the mi89qf q9cb3 .unzeqd;aximum speed around a curve with twice the radius? (Assume all 9bc zqe;uiq8q f39 .ndother factors remain unchanged.)

  What is the centripetal acceleration o* g0p47 3x0jfcsgckpl f a point on the perimeter of a bicycle wheel * c x0ckg pj7l4spfg03of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotat5 zw-osbs7u;yw4 zu:z(p1ztm ing at 5.00 rev/s is located 0.200 m from the axis. What is the centrbs o- tzzm:p4zszyuw(w;7 5u1 ipetal acceleration?

  How many revolutions per minute must a circular, rotating pr;6) +qcwq8mr-(s qkpk5vfy space station of radius 1000 m r cpq-6rp5yqk8m;s )krw qf+(votate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It go9 v3) ivj f(3 .hwjzcuf1mj-bjes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force i139 vfcmfj vj3-. jb(wu hz)jon the motorcycle?

  A 0.50-kg mass is attacheq/up,tz+l - g g/(1ei4,xx,bcvsyfu 3do4r yqd to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that thef dyo, qx u4g-c gizylx / 3q+s41tpbv/ur(,,e 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 s,u5 iz04 zq swleer4m/tring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times0lq4um5/ 4zz rw, eies 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 whirled in a verticfb)ob6 4d p:-ps7 )q jsic5phoal circle of radius r. At the exact bottom of the path the tension in the string is 3 t5 sb 6pqid:sphfjo co)-)pb4 7imes the stone's weight. The stone's speed at this point is given by

  A jet plane flying 60v.i-x q*zfki0g 1. sfi0 m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the i.if-qzxskg*i0f.1 v loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the ce0tv.zozfm 6 j6nter of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushin jzov6zt.60mfg down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot ca hm)kr: rxx:y/n stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of akxy)/h:x:rr m vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius 7dffg2) qluw(cd5l 7shorizontal curve with the tires on the vergslf 7l2wfud5gdc (7q) e of 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 cug z-rz1r4a5 e l)x-wcmrve of radius 50 m with a speed of 20 m/s. The centripetal force provided5 amcelr4r x- z)-1gwz 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 of445lv5 :-c6d hevfhs gpk)kbb 14 m/s. What must be the minimum coefhkb546 dblvh4) 5e:sfg vpk-cficient of 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. The coeffic4sqhkxi d(d6h 59zee5ient of friction between t zsd6di5(kex9e4 hhq 5he 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+1-ccfep v92huh8lf r an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s withlu 1-rchpc eff82+ 9vhout skidding? (Ignore friction.)

  A horizontal curve on a bobsled run i(d17bdioogjzk(j l , 7s 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 a/cn)e ;gvyza 1oe:fi 8* uokq7ngle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedr ww,dtxi0 7r9 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 re (xlw reeq2v ftrw/f+e,.l) v 63pisp:volving uniformly in a horizontal circle of radius 0.ff(32sxlvw6rltq w,p)eviee+. /p : r 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 t z7gn a;*+h2mjs+ru bche pit area, 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 m. (only fill in numerical valu 7 2j;*z+uacgr+hmsbn e 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 protonrf(wb mg.2s* qx6r3 vvhsz,4t 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 perslu8r) su.ll2+p ybx lq*4t vn(on standing on the Earth, due to the Moon? The mass of the Moon iu4q rt+lll2bsxunvp( .y) l*8s $7.36 \times 10^{22} \; kg$ 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 s bpp q.hb5s6uan:1i 0are moved to half of their initial distance, what is the gravitational attracti0abq:psb 6h1 s i.up5nve force?

  For a spacecraft going from the Earthnhnk +/fb+m. j toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cancel jnkn/+mf b.h+?
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 Moonn, p;a9gn(r(evf ngq7 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 9 l8ckthm+4bg3t jte (a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to grat9tl8tjheg+b k(mc4 3 vity?

  The radius of the Earth is R. At what distance above the Earth's surfacefpl,-x m ,hdaj+ vem58 prf5cxf8h 9w- will the arhm-,fmxl 5p9w8aeh5d , jcx+-8 p ffvcceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars yytm08oexyi +m6x- 0 kat a distance above its surface equal to 3 times the radius of M6 ko08x-yymxy+i m t0ears. 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 acp8/ilfo 34xhto a 7k-cceleration of gravity is alt-hc8pfoi/k3x 4 o7$32 \; m/s^2$. 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. 6fm7 xcgm3 30nh:fsgcz4mds* The Earth has radius r. If the object is raised to a height ong*3fgsd : xmf60mm4hs3 cc7z f 3r above the Earth's surface, what is its weight?

  By how many newtons does t xcr*w3b ,uuberv/3j)he weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (T)b3w3eu j* ,xuvcrrb /he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass / uvz av,;pdu6100 kg is at a point 3r above the Earth's surface. Whaap v/;dvuz,u6t is the satellite's weight?

  A spherically symmetric planet has four times the Earth's og ju1 (yj6urcx ;;yv;mf.0pumass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how moj 0uy;y;6;pm1jruux cg f(v .uch would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lif q6cd ;zgoiwl/84niyn )8x 4oe on the same line, with the Earth between the Moon and the Sun. The Moon has a mass of l nqy i;64i)odnz/g4 xc8f ow8$7.36 \times 10^{22} \; kg$; 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 ii icx.dzky. (5zhh99 zs transported 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 thr:sjf* --xt owe Earth (i.e., it just skims the surface of the Earth). What :-rosxjtw*f- is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit a0yt.zv1h la5 pbout the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The me.15l0ptv a zhyan radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of ther/ u5cuw /a*eg Earth. It is observed to have gw/5u*cr/au ea period 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 diame8f9 ,.2kvqmrzwjhs 3a ter 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 radiuaib:us,dbr (js ti.oa j46.m7s 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 orbit8v 0evxr z83jqal radius r, and moon B has orbital radius 4r. Moon A takes 20 days to comple vzrx8evq308 jte one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 3l* bovtb) /sy$7.78 \times 10^{11} \; m$ 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 av 6gm,rebey703 fkt8ycerage distance from Jupiter to the Sun? (The distance from the Eart0ft7,3y eb cy6gkmre 8h to the Sun is $1.5 \times 10^{11} \; m$.)