Is it possible for an object moving with a constanpee9v.w9jd xx 0*nx n,pzr45qt speed to accelerate? Explain.xv0 xzedwne9q,n pxj*p94r5.

  Consider a particle moving with constant speed such that its acceleration of conps9l (npmivq/r9 0xr;stant magnitude is always perperv lrpi;n (9sqxp9m/ 0ndicular to its velocity.

  An object moves in a circular path at a constant speed. Compare ao, . q+xmh60mm; avt9w t1wdsthe direction of m9ths1q om;,.av awt+xw6m0 dthe object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accelvynax,v7x.fh8e s l78eration x7v.nxahvy8 87les,fis

  Consider a particle moving w*71jwdc ob7o a*t kmcqw(v ;r(,idl+l ith constant speed such that its acceleration of constant magnitude is always perpendicular to its velocitykblo*j7(c +w mv7q rco,t ad1wl d*(;i.

  What type of acceleration does an object movingekx sx2y wn-th rh;6+ snq8io7p+. 7im with constant speed in a circular path experi oh.st;wr myxkxip8 776nqei n++ sh2-ence?

  What force is needed to make an object move in aq mw8/ivw-d9*0n a)5/eag hs 6cz wumk circle?

  When an object experienceubs2 5rzuk6/ is uniform circular motion, the direction of the net force is urizb5u k2/s6

  A roller coaster car is on a track that fo j 8s4;lzdta-j yu0ec0rms a circular loop in the vertical plane. If the car is to just mai - 40al ty0zdj;cju8sentain 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 (mass = M) is on a track that forms a circular jbn483z(ie ikmkj w;;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 minimu(z 3eki;i 8j; mkwj4nbm value for its speed at that point?

  A pilot executes a vertical div k7e (0d)l0gyncnre 1(qwmj96mk; lqve then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, thel9neqy0kwl; jcqm7)rkev6 0g (dn1 (m 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 ofg)fhf+)(s l 4gy8pw+ ;lp0iqmin l/ve 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 constal q.c06a -lmk zl7a9cjnt speed v. Then it goes around the same curve at half of the original speed. What is the 90mll k6al7-q cjza c.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 constant speed v. Then it goes a 5 8 ,uufyp5b5;gkxs6ng( (lg0haalvcround a curve of radius 2r at speed 2v. What is thg v(h8x5n(a6f, upb ckg uls l0y;55gae 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 with speed viava0; m4 ,t3 bbk1ehxg8s0 hy. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the no0abthx4gm0 a yhe1,ik; 8 vsb3rmal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banke*d vt*9l8bo ujd at 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. Wh*tu8vjb*9 d olat is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled trackp72/.8 je 6v v4w o3pzg*h2pz z;tbwc4vcxjgw is not constant, but 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 th 84pcw z*jtv2p26x ; z4e.vvgp3b/gj 7c zohwwey do this?

  Is it possible for an object moving around a circular path 7no2 buc72f dzto have both centripetal and tangential acceledzou fc22n77bration?

  The gravitational forc l)ex/rs;f:t he between two objects is proportional to

  The gravitational fobnj8/d +hmk ,/5byku drce between two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distancerq4.iy /exhf mr:nju4),yfx- between their centers is cut if.hu/,ij:4rxfex y 4 mr)q-nyn half, the gravitational force

  Two objects, with masses uytfenq,;vd z ,:x*x;$m_{1}$ 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 maqc+0e) j)yw5 .)emovccgn ft4 sses $m_{1}$ 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 universal graviynqkoqsm) xw--3, 2jktation.

  Compared to its mass on the j u42sjmtk l6b)0-xgwEarth, the mass of an object on the Moon is

  The acceleration of grav4flhtuuh vlhu155.i8 4r3 ) e xv,mtym7(stlxity on the Moon is one-sixth what it is on Earth. An object of masseui(3smmvfrlhlxxth5h u t8 )u5 1,.y44tv7l
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earhgjr.g0)s kt4 v3 ocv 9vybs(*th's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyondjg2vz k+)h-cmw- xgyj. v nqa,/x6y y4 the pull of Earth's gravitma,)x 6hv- -/2njgwq.v 4kg yy+czyjxy?

  Suppose a satellite were orbiting th:ne; /:e*espk pq*xdde Earth just above the surface. What is its centrenp *k s:xdq/ped*e ;:ipetal acceleration?

  A hypothetical planet has a mass of half that of the Earth x. .w* .v fue:*wa/ jfis 1dtjhx63ctjand a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceler vet. .jdtw*jfhi3jax1fw .:/6sx *cuation due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is y*8ipwyt*g5a z+d 0(w9 ab rzdon Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the dp0(*w w+gad98zazb*ytyr5i Earth's?

  Two planets have the same surface gravity, but planet B has twice the ztxo b 6i,ph 63c*n4rxradius of planet A. If planet A has mass m, what is the mass of planet tphni bzco*r63xx64, B?

  Two planets have the same surface gravity, but planl6c. hcl2owj hyjc .x4p9j zc);a8-idet B has twice the mass of planet A. If planet A has radius r)cli 9 jh462hwcj py8 oa- dlj.xz;cc., what is the radius of planet B?

  Consider a small satellite moving in a circulag-xi;bvz 87nlg2ug ur 7hzfn,9 9yi8fr orbit (radius r) about a spherical planet (mass M). Which expression gives this 8y7fb8u2zzu ng;99ir hlf n7gv-x gi, satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotatkr 0e-2 .hxoztm-4)fe ez0yzues in the same orbit. Compare the two satellite's spezu)my0hf0t.kx ez 2 oee-z-r4eds.

  A person is standing on a scale in an elevator accelerating downward. C hk2zzq mk2(4dompare the reading on the scale to the person's th2zm 24qkdk z(rue weight.

  Who was the first person to realize that the planets move in elli0hnu5m; a yur(qt)ersu8hl91 ptical paths around the Suuuy me9)rh8;ls5a n u10hrqt( n?

  The speed of Halley's Comet, while traveling in its ellwmhl fz(j ;pphs47j jr(59 z /qg bk;.hgjok0)iptical orbit around the Suqlj ;()h 7 4omfhs9k/5hp(b.pzgkj gj j0z;rwn,

  Let the average orbital radius of ak ;*2x4gd)x/r 1.yzk4ov/ pdpfing ea planet be R. Let the orbital period be T. What quantity is constant for all plane xv44fe1xz*n;a k ori/d)2ypgdpgk. / ts orbiting the Sun?

  A planet is discovered to orbit around a star in t +uf k2tz :uta3fux9d.he 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, c.3adu tfuk2:u ft+z9xompared to the Earth's orbital period?

  The average distance from the Earbr:;5t1wb3 awgw;t neth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-1t 3wtn5g ;r;abwew:bthird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.z og2(mofua( *

  List the four fundamentaycnz-ek92u: qhxe ea zy-(z, 2l forces in nature.

  An object moves with a constavp yqxon 2/s;+nt speed of 30 m/s on a circular track of radius 150 m. What+pxo;s2 nqy v/ is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum spee s()qc t;lr7nbd around a curve with twice the radius? (Assume all other factors remain s;7t( lb n)qrcunchanged.)

  What is the centripetal acceleration oq0 tn.en+ ut9mf a point on the perimeter of a bicycle wheel of diameter 70 cm 0nmn9.+et utq 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 friwc+hz zlu 22 mw(ugfe91-t,tom the axis. What is the centripetal accelerationemwhtl ,gut2 (91cfz 2 i-w+zu?

  How many revolutions per minute must a circular, rotating space *d6 :t2 tondl--4ymcdzk,y c7jtk6i ystation of radius 1000 m rotate to produce an ar*yy,t7d4c:micl2z6kdy -- d tkn6 tjo tificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass n4jnox /g8as2d1h0bo of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the mo1 8h4/nbo s0 2oagdjxntorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The systjsj37e76,c5ik+j 2 xn ;aeth3pz rhxc em is whirled in a horizontal circular path. If the maximum tension that the string can withstandhcsnz x+7;kj a j327e6,3rh ecpi5xjt is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is atta+mpuhwl*j a,( +d +iebxmie3 (ched to a strong 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 g+ju+he3(,pmli axb*id (w+ emiven by

  A stone, of mass m, is attached to a strong string and wzr *v.sn*ja7knqj00 )tth ; ugh-r:sohirled in a vertical circle of radius r. 0nrjo:-).g0jrzkut hnt 7 *s*sh a;q vAt the exact bottom 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 jet plane flying 600 m/s experiences an acceled/ ha:wcl4t zw; o2g(iration of 4g when pulling out of the di/l hwto w(2g:;ia cdz4ve. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vtco z59ia hs0sn9sq0f7,.zp uertical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his op as9ht0 9i0uzsz,5fqc.ns7normal weight. How fast is he going?

  The maximum force a pilot can stand is abot xx3c/e-psg8ut seven times his weight. What is the minimum radius of curvature that a jets c-3x8g /xtpe 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 with xoftj)t(m2 2 xthe tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient x 2mx)(otf2 jtof friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 mj 2.uiy ipu8jhkmf2:4 with a speed of 20 m/s. The centripetal .8j4fmij hpiy2k uu: 2force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a f0/ o ysl*kx :o8n8alkwlat curve of radius 50 m at a speed of 14 m/s. What must be the mins ao0ok lw/y:xl8k8*nimum coefficient 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 coefficienterc*;7rskd e*w(jgc+l( quql ya/- +v of friction between the tires and the road is 0.40. What is the minimum radius s7g *lwrcqe/ jdyevr*qa+lcu+;(- (k of the curve if the car is to stay on the road?

  What minimum banking angle is required for an f kh,kw vr7ubd*0(rx7 g 3lnk5Olympic bobsled to negotiate a 100-m radius turn avwfk u 50, xbl(7*hdkk73rngr t 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at p wb:3+qo xd1 eql8syq30w- lna $45^{\circ}$ 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 o41//gf.g5 q cqm/cmuh ewiq+qf $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked rpd ,drpev4din,xqa:6d4 2b,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 horizontalvzu30+,srl, tprc5 sb circle of radiusvs0,+u, lr3psrtc z5 b 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, a race car accelerates at a u2 *) u;dqpzajyniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fillp)d2zqaju y*; 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 consist:.(m; gq7zcg yf6h ftks of a proton 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 2x2nsbe re z:r7y4r v5bs+m5hstanding on the Earth, due to t4rsmr 5 v +snb:rb5722 xheyezhe Moon? 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 attracti+uk1rlf,(y k g)rh goc8jf *(bve force between two masses is F. If the masses are moved to half of their initial dista 1kfck lfg8 +* rurbo(j),hgy(nce, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward thoh6/0 s+ /ojbtbl nt7,b7dg ; yu6x*dpplzzo9 e Sun, at what distance from the Earth will the gravitational forces+,obb79bdlynx60gup o z/ t6;tp s* 7 dhoz/jl 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 w /b,d-y8 rl77; q m)adnnmltwis $7.4 \times 10^{22} \; kg$ 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 abovn:s -u2mr m6qze the Earth equal to the radius of nu6szm-r: mq2 the Earth. What is her acceleration due to gravity?

  The radius of the Earth is Rg.+y g2gfo bh(duq5 :m. At what distance above the Earth's surface will the acceleratioy ob.g:5h 2(qdg +fumgn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfaoper/ m1q3 ;jpce equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, iq em/o13pj;pr s

  At a distance of 14000 km from some planet's center-ha gzwt3 ym+5, the acceleration of gravity is taz 5ywhm-g 3+$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surfc)3-pn+,tboj a5a fvn t*u00kxro1 b 0znp;yd ace of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is itbnpn bdzry 0tj cf5)*30x,po+- 0vk1; uanaots weight?

  By how many newtons doesobc)n .u7.e wf the weight of a 100-kg person change when he goes from sea level to an altitude o.u7 )f.wboecn f 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. *l6z+nprb*r d A satellite of mass 100 kg is at a point 3r above the Earth's surface. What6d*bn rpzr+ *l is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its radfs6 pz)o ,u9z8yzi5t qius. If a jar of pean yi)5zz fpsu69 o8t,zqut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipseay0(j 9i gj74vh x9dab, the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. xa dji a0(7gh9yv4j9b 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 d 6ypx 8qb;ke35v91+b okzmqtthe 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 circu* tzoahdm 9bvdtfb;b tehs 8f/-8z,5+lar orbit about the Earth (i.e., it just skims the surface of the Earth). mfesdzbt-85 t ;o98 *adbvhb ft,h+/z What 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 c l2 azfp2ep.ao(rxr)hw1.07 wtxq8 tzircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth?zx.8h.ofq7a l x(0te pwr12wrz) pt2a (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. It isaaz,c.1d9 1*w qi(tdoj-cgj i observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the iazd( q9tga*1j1.i w- odjcc,Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of ( r.0bq4szwc a$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jmmjfob4wp z)5f o 9p;h1tra97 4o mrp4upiter orbits 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 nearlyge5jr,dfj7 37fa otu/hf m *8w 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 long does ia,8umr3hg 7t e*f5jf j7dof w/t take moon B to complete an orbit?

  The planet Jupiter is bxbh:(q mp6h, $7.78 \times 10^{11} \; m$ 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.;-qh;qp )z mlj6 iuv:zqebl9 -1vj ;er What is the average distance from Jupiter to thev1jvel;q6b- emh;r: zuql -zq)p;9ji Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)