Is it possible for an object moving with d(.) rf)jfs rghkp1/vh8gn p p 2zcv1/a constant speed to accelerate? Explain /(pr/cnz2g g)vhd81pr ph)vs 1 j.ffk.

  Consider a particle moving with constant speeder1r:7 bhklv 7n tvcy: dqq06v4j2i:z such that its acceleration of constant magnitude islvbzi::qhv e71 4ncdrq vk0yjt7r :26 always perpendicular to its velocity.

  An object moves in a ,who.dozxh q5+m7 nq 0circular path at a constant speed. Compare the direction of the object's velocity and acceleration vectors.d .m oownx0hq75zq+,h

  When an object experiences uniform circular motion, the d9(tq i(,f*sd c2zhw ajirection of the accelezd(cw9j2h s t(ai*, fqration is

  Consider a particle moving with constant spe ze ,hir- sh73q2v1r5zqs*wcyed such that its acceleration of constant magnitude is alwayc31ze 2-vy q,zh*5srir7hsw qs perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a ci uowf0 mr+26xbrcular pathof2mr+xu6 bw 0 experience?

  What force is needed to make an object move3)m :dz sqhh) mj:9whj in a circle?

  When an object experiences uniform circular motion, the direction of the net /sr jk um 1sbg 6y0j1/u3rx*niforcbi k0* xsyuug/jj6nr sr1 m13/e is

  A roller coaster car is on a track that for)txbp40:qzu 3ut 3t yr*6 jzbyqraf23ms 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 centripetal a3tyt tyzquqfp) b*ux240 rj3:3z6rb acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circula +k w9r)e:d0navg 6xfor loop (radius = r) in the vertical60nfga )+e rkdv9wx :o 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 be ij -i0p2gm q8z6e,zarc until it is going str8ijzgeib mp e0 2q-6,zaight 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 radhs f:dzp5 69bh,mh,h 4 /sktepius $r$ 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. Then it /i,twl *1+ic.bolf*o-4g c fpjeh u5j goes around the same curve at half o li4 hi/cgcobt ,*ojfe+w*.j5p-luf 1f 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 a cons :ju0m:gma,q 61u4ht*spxlu ctant speed v. Then it goes around a curve of radius 2r at speed 2vc 0am,1mtgp jq6sxh:u luu4*:. 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 r qhli9/q4wy f j5w+jm57 hsva5adius r with speed v. 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 fromvym 5i h4 5f+7j9h5ww/qaljs q the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked a oadab8:a6rbc7 1zq mgw+.x pnw- et z;,.mzu9t 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 sp6d zmga,b; qz wn-:z87muo+ a .wc.bta x19pereed on the larger radius curve?

  The banking angle in a turn +vggz/b 3:b q c4/qqjf0fg3 ydon 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," the4dcbq: jqgvf0y/gg/3q+3 bfz n go lower coming out of the turn. Why do they do this?

  Is it possible for an2ti* l50kd)eumr1-pk d o vaj; object moving around a circular path to have both centripetal and tangentiaak)k0u pvoe1-t2* 5 m j;rdildl acceleration?

  The gravitational force between two objects 6nvknma b)yx5rf z 2o388e b.vis proportional to

  The gravitational force5 )e2lh5yp 2poj0nmtz between two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their cbqzjk *+u2ly. enters is cut in ha + *zklqbuj.2ylf, the gravitational force

  Two objects, with mas (t6yga2rduv7;e7 nxtses $m_{1}$ 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 4m6fhe.ju6w tqj v; 9n$m_{1}$ 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 une1qif7c pu4.s iversal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moon no6zy3ig ; 8wm;:gyln is

  The acceleration of gravity on the Moon is one-sixth-dx kg*-k *l:):nlop qq+lhlc what it is on Earth. An object o)pqxclkq h:lgn-o* kl*+:d -lf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away frompb +q8s; u(oy(z qew3k the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it bef r+ z.9xvp) t tu;8l;9uyhtzcyond the pull of Earth8tf9v);rhp tx ;y .9cul zuzt+'s gravity?

  Suppose a satellite wth4v*hbs *k9;j foypz8qp: .tere orbiting the Earth just above the surface. What is its centripetal acceleration?4zvh.;f*p*kpoy9 b q8t:j sht

  A hypothetical planet has a mass of half that of the Earth and a radius of twi2y8 ,n xf03yznoyr9 jtce that of the Earth. What is the acceleration due to gravfy32ro 8ynj0 xnt,y z9ity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity u+q 8id x5m8qxon the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Eartim8 uq+d5xq 8xh. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planeowam /ihz *f44t B has twice the radius of planet A. If planet A has mass m, what is the mass of wm/ f*4 i4ozhaplanet B?

  Two planets have the same surface gravity, but planet B has rfbg r us tqgs*9;4l/rx68c9t twice the mass of plan c t4*qf rs;ur8glrxst 6b/g99et A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radehex;3b dg /z2ius r) about a spherical plad;z/e 32e hbgxnet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the maskvbs j0).39anu8lzn ds of satellite B, and rotates in the same orbit. Compare the two satellite's speed jln)b8z vakun903s .ds.

  A person is standing on a scale in ,5)hfytiegsst679vwj* or6o an elevator accelerating downward. Compare tsi*)96 f6ett7 w sgv,hjyoro5he reading on the scale to the person's true weight.

  Who was the first person to(/l9r( hrndpwonz/ c1w08zvv6bpu - u realize that the planets move in elliptical paths aroun 6l/1oz w d nc80uuprb(-r(hv/n9zp wvd the Sun?

  The speed of Halley's ou+c(kv i:rw t 1qpw/,Comet, while traveling in its elliptical orbit around the Sukopuiw(/: cvwq +1 t,rn,

  Let the average orbital radius of a planet be R. Let the orbital period be Telr ,yq djgd15 /8 m7(1hekod 2wmnxi.. What quantity jo(dd.enexl h1d/ 8w17gmrimq, 5 k 2yis constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy And0vzz bvad 199q t+-eym:k tk*vromeda, with the same orbital diameter as the Earth around our Sun. If that st9 *k:-vytvektz01b q +madz9var 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 a n-e 8l* yz;) pliz(h-d)k )ipdalmb;the Sun is defined as one "astronomical unit" (AU). An asteroid orbits thehiz8);zdal -ial p)-(lym); bke* dnp Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.m;d bjmh*g h 31cco+w.

  List the four fundamentalz f8: klqte2d0 forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track o8m hbykn+0 ay7f radius 150 mnhb +8mky70ya. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is t 0ko5k 4ji(-eo; ew smx)weve)he maximum speed around a curve with twice ;jsie)0oem evww () 45xe-kkothe radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a pointl *-4pq eqmycw39z pf4 on the perimeter of a bicycle wheel of diameter 70 cml4*mpqycew 4 p 9q-zf3 when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the.u- b:)nb rhuu axis. What is the cebuu)nr hu .-:bntripetal acceleration?

  How many revolutions per minute must a circular, rotating l(.lut mwl6mu4uu* hyx5d5k 1 space station of radius 1000 m rotattyd( 45 mxukw6u u1 5m.lh*ulle to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes9f4:s n dbe(ui around a 13.7 m radius turn at 96.5 km/h.e: d49nfiu bs( 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 is whirledhcz 3gxmd5np /6vh7uq 3y6v2x in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the ma63z/g7q5xvpuc n3 hv hydxm26ximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a sf7b* d. r0fotti:val *trong 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. The stone's speed at this point is givenvbltf:7aro . 0*td*i f by

  A stone, of mass m, is ayt9cl+xna1h dz *+6pd ttached to a strong string 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 h d1x9p++cn*ylz d a6tweight. The stone's speed at this point is given by

  A jet plane flying 600 gej1:pb,6z qtm/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in whic6b gj1ztp:,qe h the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the o3 20lu ble*nu+0 dndyny1 rc.loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on hisyd+c 0 1l3drbu neo2n*u0y.ln seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What y)x)g6ctv s 5h8wn esm8(nq8uis the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a e nmq)v()x 6w8c8hutg8 s5ysnspeed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m 88w p 5fkhmc2xradius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Awcmpx8h582k f ssume 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 aw -;j r/x(,nnm.rgbue speed of 20 m/s. The centripetal force n-mruw jx,g/ b(;r.enprovided 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 wvjiuu8we(5y5 jjnsm*57 m4g m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make thiu7y8j nmuw4jsgm (e5v *w5j5e turn?

  A car is moving with a constant speed v around a mr9 x45c gnmq+level curve. The coefficient of friction between the tires and the road i rgq9nmmx4c5 +s 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking3wmhtx/ p (q 5 8mig)mzy2y3ys angle is required for an Olympic bobsled to negotiate a 100-m radius turn at x q3 8y/3mp2mtzmy)wgsi(5hy35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banky/rs.6x-2 8,x -rafou o9t - it.omq)ddxrxvied 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 ( fp f-r4j,,:vairqs :vn*jswradius 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 atbquwopqx3lee*1 c / 72 $45^{\circ}$. 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 pix;w(k)q5agg3 nis0 string is revolving uniformly in a horizontal circiw5( sin )p0;akgg3 xqle of 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 area,s6/8vz d b fjeer3fnq::oni;l+ f,q0w a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on 0n:f/3fjqiv eezlw +dqrnfo:;6b,8 sa 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 of massfd ka3 yd;8b6q $1.67 \times 10^{-27} \; kg$ 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 fodm s;; p+y +5/ukwzif uh0p1xsrce on a 70-kg person standing on the Earth, due to the Mikwypdfhx5+/ +u ss;1pmu ;0z oon? 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+,iv mtt4v(t d between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive forcmtd,v4+ti t(ve?

  For a spacecraft going from the Earth toward the Sun, at what distance from j/g3l(do oe9jthe Earth will the gravitational forces j(d/3eogloj9due 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 is mz*6h :l eo.xh$7.4 \times 10^{22} \; kg$ 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 abow2 vojh878gor,li 6qw ve the Earth equal to the radius of the Earth. j,wh8 rvw8l7qo og 62i What is her acceleration due to gravity?

  The radius of the Earth 9bk 3rhhcrxez 21i-o6s1kqz9sqb* d1is R. At what distance above the Earth's surface will tbhzekh*i9r93 qx1q2s- d 6cs1o bk1 zrhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times-kkj fmh7or5 1 the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, ik 7kf r1joh5-ms

  At a distance of 14000 km from some planet's center, 56 gr9wwam t:pthe acceleration of gravitywatp: gmwr5 96 is $32 \; m/s^2$. 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 radiusja,am 5le +d n6c5nl*m r. If the object is raised to a height of 3r ajl, canme*5+5ndm6l a bove the Earth's surface, what is its weight?

  By how many newtons does thwmb07+ik841s 5tozlgof ttu8 e weight of a 100-kg person change when he goes from sea level+t u4lg88 tm1s7kw5 f toobz0i to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A sau-o/gi+ *lc 5 vpxh(qxtellite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weight?5l*p-qc+vxo gix h/ (u

  A spherically symmetric planet has four twnxy(z+. 9kn himes 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 would it weigh on the surface k h(nn 9yx.+zwof this planet?

  During a lunar eclipse, /r*inb9r wfn.7q w v2ithe Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Suwiqn* 9.win/b2fv r7 rn. 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 tr9s c b.duxlhqh-o -i*4ansported 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., itsc,w7w5g e(6by9 fuma j.1j zbvc, 7se just skims the surface of the Earth). What is the speed of the satellite? (The mewe9azef,,76 .7(y gjb1csu cmb5wsvj an 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 toeg2lzdc)5a h: ch4c 3he surface of the Earth). How long does it take to make one revolution around the Earth? (The ec4c)ozcgh2lahd 53:mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbib4dhi9vl y5s8qv3 r8tt 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is thevd85s 38iqvlr9t 4hby mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupi3g gh6:9zfjmynx+1ail1b , jbter, has 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 orbits the planet with :p,jk/x cdv7ya 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 circulfflqb akr.dfcd (.3-orgw99: ar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbitw3. r.kfl d9co q bfdf(a9-g:r. How long does it take moon B to complete an orbit?

  The planet Jupiter is 7g22xy/zwxv f $7.78 \times 10^{11} \; m$ 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 tsqoth0v-chm2 x4, 06,taoyv bo orbit the Sun once. What is the average distantyth,cqvxho0- am0 6ovb4 ,2sce from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)