Is it possible for an object moving with a constant speed to accel tlhw:dp69d clf ;1c3aerate? Explain.pl1 d9t 3 ccha:dwfl6;

  Consider a particle moving with constant speed such that its afl11svv: -vzb cceleration of constant magnitude is always perpendicular to itzfbvl :1svv- 1s velocity.

  An object moves in a circular path at a constant speed. s3 xq3m v71jx zfodb,6gi-c) gCompare the direction of the object's velocity and acceleration vect1ig,xbcx -d jsvzq)fg3m673oors.

  When an object experiences uniform circular mot*1it7+k4fslz rg/ d rpion, the direction of the accelerationrr471lp f/ +tzki* dgs is

  Consider a particle moving with constant speed such that its accj9nbp;) uerl8f;3rwq eleration of constant magnitude is always perpendi;; l9rbfq3w)epnrj u8cular to its velocity.

  What type of acceleration does an object moving with consx0k q)z otrh/h;*zu(etant speed in a circulaq(/)0 zt* ohkhuzrx;er path experience?

  What force is needed to make an object 7uh m. dp*qni;9cr-m5newi m /move in a circle?

  When an object experiences uniform circular moaq c;vbqn o)a.47;yt ation, the direction of the net force n7)4;aoq bact; a v.qyis

  A roller coaster car is on a track that forms a circular loop in jo *vljy8 9ja/the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum jvaj ly8o*/9j value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track 6a9z vlz6xu.depqvba e4( ;1y5jgjk : 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 : k6(gzzyaul5. 4a ej91 bdjvx6vepq;at that point?

  A pilot executes a vertical dive thj3 7,ztidcwmfq0-1q2h0 f walen follows a semi-circular arc until it is going straight up. Just as the plane is at its lowe7, fwq10al w03q j i-dh2mtcfzst 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 curknq7to3b k7y0 .ec+d lve of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a cu,mq ax6,nx9 uxrve of radius r at a constant speed 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 the curve for the second timam n,x 6xux9q,e, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it f41b)7-hk efkv x x.vzgoes around a curve of radius 2r at speed 2vxvfbz-.e1 kx)7hf v4k. 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 w1dffpc r,d;29 bg vqo2lh,a p2ith speed v. If the road is frictionless due to ice, the cp, p f,f2g9c d;lv ra2b1d2oqhar can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one hashy s vp0f-of4u3 ob1)y twice the radius of the other. The safe speed (no friction needed tf1)0-3ov soy 4pubyh fo 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 turn on the Olympic bobsled track is /l0 fftbk*hp +not constant, but increases upw/lk+0phf f*btard 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 objeq 4:y (hrbbpk .2u2ctect moving around a circular path to have both centripetal and tan p22br (etkb4h.cquy: gential acceleration?

  The gravitational force between two objects i-hq, 2lc1oqh ts proportional to

  The gravitational force between two objects is inveretu-n q j np+7qp5o24 mm(h99*mnjf yysely proportional to

  Two objects attract eao .o(upeq2 h/xch other gravitationally. If the distance between their centers is cut in half, the gravitaoe.pxoq h 2u(/tional force

  Two objects, with masses ,/ fc 2cjj-o;if2ud3hl n6mkj2oui2.t y5gp 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 masses x/sd hg(4x)vztka h)4 $m_{1}$ 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 universe+jf5zs-c3( 0p *vb6fhi)2xsp xvmysal gravitation.

  Compared to its mass on the Earth, the mass of t :z1ve8xhl2f3b(uwn an object on the Moon is

  The acceleration of gravitav(sne06 mqp fh i(w05 qlg5r+i,l2i ly on the Moon is one-sixth what it is on Earth. An objecfrvl,h llmq i qsnp65( giwi+2 5e00(at of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'sujtn9-r 9 dx-y,iztu 4 surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyonds) ,/;xxzd+1 zdsazpl xgm/.f the pull of Ea ,dss /xa +lpz)m1zgf;zxx./drth's gravity?

  Suppose a satellite were orbiting the Earth 2dq ;g3tdt:uexb69k djust above the surface. What is its centripetal d6u: 9bq2ddtk 3gte;xacceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius x:vgl ypj1mjle143e : of twice that of the Earth. What 4:m1l13 g jlpxj:eveyis the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what itzxfz66 heg+:x is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Ea hf +zg6:zxe6xrth's?

  Two planets have the same surface gravity, but plan1fomug/j dea1za1vs * s4s26c lb;z .net B has twice the radius of planet A.c1su * e11nfzlz;6 a.m ds4gv/bs oaj2 If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B ha37 :tpj2rqgx d0kx sf+s twice the mass of planet A. If planet A has ra37 sdq +j x:2t0gxfrpkdius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abf5+ 0kd lt :zfuibx;i0out a spherical planet (mass M). Which expression giv:lxkf+0 dtfui0 i 5;zbes this satellite's orbital velocity?

  Satellite A has twice 8syb0 6 w/bndmthe mass of satellite B, and rotates in the same orbit. Compare the two satellite' wmsn0bd8 b6y/s speeds.

  A person is standing on a scale in an elevator accelerating downward. Comp:s*ja6; .nzvxe nql,t are the reading on the scale to the p; eazl,st6:x*q .jnnv erson's true weight.

  Who was the first person to realize that the planets move in elli2ibso c214ezr a )u)diptical paths around the Sun?r 2)s4o )2i iazecb1ud

  The speed of Halley's Comet, while traveling in its elliptical orbit ark0zg w,nsqt f +:bb2o0ound the wts02,:gbf +zkb0no qSun,

  Let the average orbital radius of a planet be R. Let the orbital periode0nzna4nys , .k*ij b) be T. What quantity is constant for all planets orbiten b.n0*kz),i4 snajying the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witeh:uk vh31x/3hsqd -fh the same orbital diameter as the Earth around our Sun. If that star has 4 times t xs-hfh k/3qd:1vh 3uehe 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 onn((puuv2 3i 9t8 x tvop:a1cv ktee0+ze "astronomical unit" (AU). An asteroidpk8i cv30 vtxu2:pt(oet+evn1a ( zu9 orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.bhm9p;0 dm e *p:exm3g

  List the four fundamental forces i7whvo o-r:d:-a,vj( dso+eocgv9 ;wv n nature.

  An object moves with a constant speed of 30 m/s on a circular track of ras30m j8ph2zk) v1cd vzdius 150 m. What is the acceleration of t82dmv0jh 1)kz3sz vcphe object?

  The maximum speed around a level curve isrsi nu,emqs v ld+f,2*7e;1yn 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other favf+n , ;l*i2msye suqn1 e7dr,ctors remain unchanged.)

  What is the centripet 94unro:,i mrqal acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is mo,rnm or49:quiving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from :2fq-x eferrkh2my-5 the axis. What is the centripetal accelerat -2 xerrfekhmfy-q5 :2ion?

  How many revolutions per minute must a circular, rotating spaceqs0gzq2fflgt i x a 6,-7n+/0eoan9dj station of radiusdftz7l ,ge6q/ 0fx-ji9n+ aa2qsog 0n 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It g;lj./ceqr j7b83 x hoboes around a 13.7 m radius turn at 96.5 km/h. What is oq7.cr/8jbb3 l exhj; the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.6r2 n,ab8 rjji0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maxi i62b rn,rjja8mum 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 vertical ci wpqh6myj:r 35p;flksn (a,j r:ymd(5 r6pf,pr y5qsmmlhjr( (3d ;ya:k5n :jwcle of radius r. At the exact top 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 stone, of mass m, is attached to a strong string and whirled in a vertivpf; yxf b(cf-dw3u+2 *nkw (xcal circle of radius r. At the exact bottom of the path the tension in the string is 3 times the ston-xf2 u;y wc(xnf fd p3(b+w*vke'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 oultzxo8e8h2 i /kktjs 75u 6v-it of the dive. What is the radius of curvature of the loop2ui7io6kzhjv8 t /5sl8x-ke t in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the lofz * qy6zu9 nz*i-9(vupft xd2op is beneath him) ody-upt9*uxz zi 2 z ff9nq(*v6f 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 going?

  The maximum force a pilot can stand ipohe fhxy8 u 4wxczt39rk/37(s about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pu3phz/ykxw(8 o3fhce7x9tr u4 lling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m ra kqan ;b 7 ba z)58nf+2yoecyt)upo80sdius horizontal curve with the tires on thenk82y 8+7 )a5fn s0bzoby;)oa tpcu qe verge 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 curve of radius 50 m with a speed of 20 m/sl4(i.3 pufem w. The centripetaluli4mef 3p.(w force 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 a speed of 14 ( k+xi*f,o; qnisyp hoz(wb+daa1 .y .m/s. What must be the minimum coefficient of friction between the tires q,o++ za(ni d(.k.oyx*pi wf1;y sbah and the road for the car to make the turn?

  A car is moving with awubvn7en w 8 mmh./h +-40beaa8dorn* constant speed v around a level curve. The coefficient of friction between thewb w7 /*ne v ehaohm- m+un4dr8.a8nb0 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 fo op:jbxl86 zq4eybj.v 9+7dbuswg/-or an Olympic bobsled to negotiate a 100-m radius turn at 35 m/:+s6b9d .q-7o8 bewj bj4 /yzxp ulvgos without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a qi9c;n95wwiz)im yoq7a rk w*k 9.j4q $45^{\circ}$ 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 radiu if0tjp,m 6:aqxs4ln 2zq+sw-s 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 ur k(kvn g51 h-wax me(nf/86im 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 string is revolving uniformly in ab()vlyu:v vp6b iqk;3 horizontal circle of radius 0.50 6; iyl3bv)b(pk uqvv:0
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 car accelerates at a unifo mn0 cw-92ltvnrm rate to a speed of 45 m/s in 1v2l nw90tc-nm 5 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 o 0n-r(yxdj hg3t )jw(kf 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 o38rdk5zm5g n y 4ft:aun the Earth, due to the Moon dg4uzn3tr5 y 8:5fmak? 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 F. If the massn m(-+8eceil8e7k xq ses are moved to half of their k (7 nim sl+qe-8e8xceinitial distance, what is the gravitational attractive force?

  For a spacecraft going bfgi)ph br11(qis 1y- from the Earth toward the Sun, at what distance from the Earth will the gravitational fo-gp(bq11i syfr)hi b1rces 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 iscoy(v corw)9rv91 sw 0 $7.4 \times 10^{22} \; kg$ 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 ynnuq ac;..ve2 1ze zi iv5*t(for a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to greue.q vva .c1( z2;5 itz*nyniavity?

  The radius of the Earth is R. At what distance above the Earth's surface will,sf)f sffx7ca * 3o//kxgyz* a the f3s g*xafzsya* fc)x fo/k 7/,acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times the r l*bb6vw1*ik7iw)ee radius of Mars. The acceleration of gravity of the satebi w*veer16klwb*i7) llite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some plane9zystb8cptg0we 0v+gd6 / 5y4putq1 nt's center, the acceleration of gravity dn0t 18 vpst4ty5qp+eg6c9 w bu/0 ygzis $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N c,j0f iw t3d352farwh9jvem+ on the surface of the Earth. The Earth has radius r. If the object is raised to a he3i5w2mc0 3ev ajrf+f 9dj,thwight of 3r above the Earth's surface, what is its weight?

  By how many newtons doesos3swldyn5 q:6; w3ccp; adw2 the weight of a 100-kg person change when he goes from sea level to a3wscqa;5ocdw lds;:pw 6yn32 n altitude 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 1 5e;n2hnfos i xd0cen8t- 4u3m00 kg is at a point 3r above the Earth's surface. What is the satellite's wu034 x5 fc hems-den2n;t8inoeight?

  A spherically symmetric planet has four times the Earth's mass and twice its upm2l,k7 -w+xhonf k9radius. If a jar of peanut butter w+ xh9w 7ukfmo ,-pln2keighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Eaa.qy;h-q2-bcosnuux8.gz e; rth, and Sun all lie on the same line, with the Earth-hb-zg8ns.xcqa qu ye ;u2o.; between 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 transportecc/ -tt1giwa vw*b8 ija7w2w1 d 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 orbi7hxmmc*dq3 (mz: ;t oit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite:mmx*qto7zm (i;h3 cd? (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 skims tsqmm 9y/x,m2q d: ,mch4va:z rhe surface of thr2mm /c z,xaqm,dsvh9:m:y 4qe 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 orbit 230 kn,8 boxstz1;em 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 ra,t8b1 ;xoz sendius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter ofl+m1dj oq cg+g;6-i4 4gxnbji $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the plan88 ep-tpozz4wet 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 orbitalz3qmdw 7oa)7a vuw.qp qz+(6w radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. Hoo (zqa7 vpww+q wqm73d.uza6 )w long does it take moon B to complete an orbit?

  The planet Jupiter i0 ki 5)7(kxrro ho,knd ep.0ivpjg32as $7.78 \times 10^{11} \; m$ 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 f 5cwwyzo6 p/;8r+ blsonce. What is the average distance from Jupiter to the Sun? (The distance from the Eart6c pfwsl8;w+ob /5yrz h to the Sun is $1.5 \times 10^{11} \; m$.)