Is it possible for an object moving with a constanrbez.4 )ceqyo6ug x /0t speed to accelerate? Explainr6gqox euz0 c) /4e.by.

  Consider a particle mo p1xll0n9-d1(zyp pfrving with constant speed such that its acceleration of constant magnitude is always l f- rpp(9py1l0 xn1zdperpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dm z2:vtj0ryeq-l (:hlirection of the object's velocity a -j2zvy lr:h:0qemt(lnd acceleration vectors.

  When an object experiences uniform circular motion, the di7gu7 p;h0dvcf rection of the accelerf0 ;du77hp gcvation is

  Consider a particle moving with consta ;i 8gx99rpoount speed such that its acceleration of consi9xp r9u8go ;otant magnitude is always perpendicular to its velocity.

  What type of acceleration does an objidsi-l4-w or4 b. +ziwect moving with constant speed in a circular path e4-o .z+br i-di ww4slixperience?

  What force is needed to make afg/ 2gn* jdk)rn object move in a circle?

  When an object experiences uniform circular motion, the direction of the net f9 ua31 igm 4v3gc2hitlor ighli349va2 tgm3u1cce is

  A roller coaster car is on a tracpg2a kc2+ jj2 t:hq+uqk 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 its centripc2t:k h+j2ua2 qqj+pgetal acceleration at this point?

  A roller coaster car (mass ngz3o 9.c2y xic; ihsmjx.+o )= M) is on a track that forms a circular loop (radius = r) in th);ymc2h.x9 3ixi+no. z sojgc e 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 folly c dzi,g5hkd:ra:ob)-5uxz2ows a semi-circular arc until it is going straight up. Just as the,yxiddug2c)-5z5z: abr okh: 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 cuiaxjb 7 y( ;8yur+:faorve 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 v. zr: w i4-f)yerThen it goes around 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 seconr- i)yf4e:zwr d time, compared to the first time?

  A car goes around a curve of rlbx 7/ fh1m4cadkwf o.j0:.ua 9+uocfadius 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 arouuo/47axcajm+ : odcwk . 0 .b1uflfh9fnd the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed 4sk.wp5)w*1 olvhd55ufw+ xwu z q2gnv. 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 wnplgwx+qz.of*4h wv55 uu5wk1sd)2from the road is equal in magnitude to

  Two horizontal curves on a bobsleda;ipwvuw+ s18v a f*h; run are banked at the same angle, but one has twice the radi;pvas8hiwu; avw*+1fus 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 larger radius curve?

  The banking angle in a +;y4 wbo t 2wusdcup;m:1l rl/turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lobsu;mc2+d;1rl t 4w/u:lw pyower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to have both centri8) un itnk2frz u8)yj4peyuk8j 8)2r zuif4ntn) tal and tangential acceleration?

  The gravitational force between two owx+ f/62 qmalzbjects is proportional to

  The gravitational force between twoe,tp/t 3hvzw86l( q7 ehr)qjo5nme7j objects is inversely proportional to

  Two objects attract each other grd( l/f56 cd/owtu vk .2zr,s8zul.eyuavitationally. If the distance between their centers is c.durv5w s2d(6l8/zkuueyc fzo,. /t lut in half, the gravitational force

  Two objects, with mass;v0,4z +bi mholal4 5 jk)louoes $m_{1}$ 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 massesx p;ikmaay:3; $m_{1}$ 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 unijs 8ja 5.p(napversal gravitation.

  Compared to its mass on the Earth, the mass oroc;ltrr o-y2x7 thw9qs 1 5f9f an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what *z)sx4u k+pceq(rk6fit is on Earth. An object of mass+*kq ) 4f epz6usxkcr(
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'n y.)ofvl5t6 js surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point ist. cje *k263zza bo8zz it beyond the pull of Earth's gra8zc3.ztk bze z*6oaj2vity?

  Suppose a satellite were orbiting the Earth just above the surface. What a oz-) n67hca 7a,*tn ryl-gbois its centripeta)a6-tr7zb7oyca, anoh gln* -l acceleration?

  A hypothetical planet has a mass of half that of o : qx)9djbxz)the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planzjxq) b):dox9 et in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of t -mfe/+3,zd j0mx(0or+rk bubt.izygravity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Eario0r,(mtr um- z bbt0fx/ e+zj. y3+kdth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has tz sl0ef 7 ,dk 0mgek+t5bc(+ld+lv/qs/q zid/wice the radius of planet A. If plane 7es +tq/vl c0/qeidlbf +05gzmd,kkd/ +z (lst A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B hoc-dkg j*yq,8i c;444 1wlhp kaad-wcas twice the mass of plana4h-;wl c ic4481d*gcw,ok-dqa kjypet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite m /0rq .tul;so8xefrpzx5 h6 7fab;a-aju-j :moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital velocismb t-a0hajjuo/x6 l. 8;7 5ref-r:pfzaqx;uty?

  Satellite A has twice thnt mrv4w degsg8,e-7 m n2;-ise mass of satellite B, and rotates in the same orbit. Compare the two satellite's spegg -e8 es7wmr4,tnmvn;-ds 2ieds.

  A person is standing on a scalu zczy moj0 ;,,h4lt+8 8trbcye in an elevator accelerating downward. Compare the reading on the scale to the person's true weigh 8j4;yh,btr ult0cz zm ,o8yc+t.

  Who was the first person to realize that the planets move in elw+ -ywn-dakip vr)p .:liptical paths aroun)i-vpwrwy. kn -+p da:d the Sun?

  The speed of Halley's Comet, while traveling in its ellipli:y1kbya p gd2382lwtical orbit around the Sunyl:d1 bi ag2k32 8wply,

  Let the average orbital radius of a plapuz emke mm rs *cd+03hc57++gnet be R. Let the orbital period be T. What quantity is constant for all planets orbiting esdzhu +3kmp g0+ r5mc cm*7e+the Sun?

  A planet is discovered to orbit aroug6 jt l:7z ;/chc6ggyqnd a star in the galaxy Andromeda, with 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 revolution of that new planet be, compared to the Earth's orbital periogzg/t76c6qh;:gcl y jd?

  The average distance fro cix+wvi6zjeof1- ae+ u:d;a,m the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third o+eaov1f, z +c-u wed6xii :j;af a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.fdxf)w8)u8( y+envbu: */ yayg9 rtmi

  List the four fundamental forces in nax8oxy+o4s zdit w+:eoatwgc 2 h9-**uture.

  An object moves with a jup-lf638zd)sm2xpn dri :s*0cv4 ww constant speed of 30 m/s on a circular track of radius 150rlzp sf:2v8) pw sxd-cw0di6mnj * u43 m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Wh4.ful jvk b*iqvwv(kw8l 43p1f8yp +cat is the maximum speed around a curve with twicelw8c*pi8f(v 1fwly.v pkk b34+uvj4 q the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a+vq z)a,:v0 k( vh0hlfvz3eq u bicycle wheel of diameter 70 cm when the bike vefu+)0l0v:3 hhqzz(vak ,vq is moving 8.0 m/s?

  A point on a wheel rotatin fr67qeril+gl k blcb vm14,46ka(d2lg at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal accelermdlc1 46lrlq,bb2gve ( +6ark4i 7kflation?

  How many revolutions per minute x 8zv.ij*jp -emust a circular, rotating space station of radius 1000 m rotate to produce an artificial gravity of vepz.i-xj*j8 $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It gon6nyidhj 6b3 +es around a 13.7 m radius turn at 96.5 kmhi bd+6 6j3nyn/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. The system d5cn bci6 gh(0u;o:zu is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mas;cu6g0o(5cz ih u: bnds if the string is not to break?

  A stone, of mass m, is3ek,gs.:oiqfz)bc 09 mk i5fi attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the strin.ki)s3,ekf m :9 i 05fcqgiobzg is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached m okh8e6vtne m;7bl56to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension knhm7oel6 e58 mbt6v; 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 pxads a6*sq/)oulling out of the dive. What is the radius of curaa 6/*)osx dsqvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center e6 l/z ouk)b/n+ pqof4l n;l7jof the loop is beneath him) of radius 3200 m. At the top ofl)bl;k 6/nuolfq4+ j7z/np eo his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stanenk xzr8+ lu. ce48a.6i m:qthd is about seven times his weight. What is the minimum radius of curvaiemlqhxc r+kz ..u8t :a468neture 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 rounds an 80-m radius horizontal curve wi24cm v/8 n:1yrag scmqth the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficie a14:2/ 8mcsvcn rymqgnt of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 mb (b7d* b2cpzb with a speed of 20 m/s. The centripetal force provided by frictizb7pdc(bb b*2 on 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 * tyqj ddzn7o6n* 7*xl14 m/s. What must be the minimum coefficient of friction b7nnl z* xotd6djq 7**yetween the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curv1odx8c lx9 c2ee. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curvx9d 1xc8 lceo2e if the car is to stay on the road?

  What minimum banking angle is req0qijg bv2o q0/uired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s0g 20qqo bij/v without skidding? (Ignore friction.)

  A horizontal curve orauxn8 x6()j1eie l t9n a bobsled run 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 1006 :m(f hy5/- z.eqbmh8yxt2ht9blxzp m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m pwbic : kw 0(mg/nifvsawtp5*n) -vj*p;u7/yis 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 revolving uniformly in a hor to2chw/eq2k j6+hgr5 zddy1dg :l8 t,lzn6( gizontal circle of radius 0l/ dtng zcjg:tdq 6rke+y2lhz15h2d86 g,o(w .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 race b4pwxx2byi),q +x d m9car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular trackpx,+29 xy)i4wdbm bxq 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 pr dk )7xx,):klrug2hb/2 xlorq 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 Earylfrb9w-, 5cd, +1te; xocoputh, due to the Moon? The mass o1f ; 5+o 9xtdpubroyl-c c,e,wf 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 F. If the masses a*2r jrx)v1a z3v ns1+sj)go kgre moved to half of their initial distance, what is the gravitational attractive forgvg+krj )nsv* xsr13 2j)o az1ce?

  For a spacecraft going from the Earth toward the Sun, at what distance from sc*kc i p:zueer8k+;9the Earth will thkcs8ikcezpr 9e u+:;*e 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 tslrck v 7r2gta6q 0 bfpc.ax0y-8l 03is $7.4 \times 10^{22} \; kg$ 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" aihk0z zsd5j59 t a distance above the Earth equal to the radius of the Earth. hz0z kji559 dsWhat is her acceleration due to gravity?

  The radius of the Earth is R. At what distan tj8d1b; nzx. oabj,+dce above the Earth's surface will the acceleration of gravity b.x d;bj,atbjd1zo n8 +e $4.9 \; m/s^2$?

  A satellite encircles Ma-ep rtxupe0lp wc +,4/rs at a distance above its surface equal to 3 times the radius of Mars. The accelex,rep 0 e/4- p+wtpculration 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 somehr:l0fyw-4-cd 5x g b u-zqp,r planet's center, the acceleration of gravity i5rgd: uyzf bp,qrcx--h-40 w ls $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on tc1hpcm/4 irts 73*q o6z/0vgij qm, dzhe surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Ed1mz j0/isqt7qz4 h p,3crc*gv /m 6ioarth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goesn4 jxrta7rz eyq 3dis5012qe2 from sea level to an altitu125z7 t03diaje qsyxr2 4 enqrde of 5000 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 1uim8 nnqen9j7za96 *aoxg5 jpoint 3r above the Earth's suoea 65 nqjnun19axm9 *8igj7z rface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its.jn e3thb8ge()hqd+l radius. If a jar of peanut butter weighs 12 N on thetjdqhh.ele() 8b+3n g surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on thzwe, v:g 5ghh.e same line, with the Earth between the Moo,hvgw.gz: he5n 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 transpocmh4c5 ,ptn c7rted 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 the Earth (i.e., it i2p p)4q0ejpjjust skims the surface of the Earth). What is the speed of the satellite? (The mean jp0pipq4 e)j2radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aboug2n- tlcvp+.lm2v,d yt the Earth (i.e., it just skims the surface of t-nctlvp.+2v my g d,l2he Earth). 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 orb ccb;i5e1zrw+it 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earz wbi+e5c c;1rth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, 7 x6v2cnulkw*,2mc q lhas an 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 orbit qn6 wi5d4+vy8sgm8 res 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 orbif )qg,;u r,5e7ho 3p9 klym7hsm/y pdntal radius r, and moon B has orbital radius 4r. Moon A takpk p,,e5)o7 gfmy3 hyrnh/lu97md;qses 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is oufwmq9 e )hhc2cxw76g-d 9 a2$7.78 \times 10^{11} \; m$ 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 onc :nx5d qwk 51vbxw)guosa)5 4ne. What is the average distance from Jupiter to the Sun? (The distance 5n nks1xx )w)dv:oa55qg4wubfrom the Earth to the Sun is $1.5 \times 10^{11} \; m$.)