Is it possible for an obf2 ;* w.a,3mom5nuqs ix4z bfbject moving with a constant speed to accelerate? Explainfofqz4;bbwn *.us x35 i,mma 2.

  Consider a particle moving with constant speed such that its acceleration of * s g bfxi/qcxl,-5/fkconstant magnitude is always perpendicug c* /xf/iqlfbxsk -,5lar to its velocity.

  An object moves in a circular path at a constant speed. *+un: pm. laiuxd ,y-vx7f *erCompare the direction of the object's velocity and accelera nyir+d :f7pxv,e xu*a-ml* u.tion vectors.

  When an object experiences uniform circi20aw()+qxgmy+xw -m5 miqhdular motion, the direction of the acceleratim5 2w0mx( di-ygq q+)xm +aihwon is

  Consider a particle moving with constant speed such that its acceleration of d vkr-b)x/unz-;l ;m mconstant magnit kvmr-mu/xdb);z- ln;ude is always perpendicular to its velocity.

  What type of acceleration does an object moving wc9ufo 49- tgr.lyca w2ith constant speed in a circular pat9cocy-r9 u lw.f g24tah experience?

  What force is needed to h ua0i3zqt*t:make an object move in a circle?

  When an object experiences uniform circular motion, the gxso w :ct-8 g*.stduvhbl* /9direction of the net forces.9 sbvo-l*h dgt x8u *cw/:tg is

  A roller coaster car is on a track that forms a circular loop in the verticql34dh)jpv mt1: 7tojal 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 acceleratio4mjd pj:3lht1ov t7q)n at this point?

  A roller coaster car (mass = M) is on a track that forms3t72 oiu-5c+ k mvsayr a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the tc-52 +v7uitymakso 3rop of the loop, what is the minimum value for its speed at that point?

  A pilot executes a ve rz) xr+zj-)-q blp xh9+iyf1urtical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forcqh1lir+xz pb -x)9yuj-fz+)r e 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 w( 8mgqpi16wyradius $r$ 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 constr0f x+/ph7w,u*2 lvh-tadrz t ant 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 time, compa/0 l-xu z7rw ftvt*a+,p hhr2dred to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goerhi rxhw* 6:ui ods6oam.z(*/s around a cu* r.xhh r6*dmi(6si/uwoaz : orve of radius 2r at speed 2v. 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 banke0)5cie kjut 5mlc7i8yd curve of radius r with speed v. If the road is frictionless dl )yuc5k i0jc 7ei8t5mue 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 magnitude to

  Two horizontal curves on a bobsled run are bi 6p9qz.r6lx 7tqa/ys/fym: panked at the same angle, but one has twice the radius of the otheis axq py6lyz//rmp9q6:7f.t r. 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 f30l,tc3c phrx-lx z3n xxu3)1-hxjy a 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 lower comi3 -xcy-l1, xhzl)x 0 tc3n33xpuxrjf hng out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to have both centam,xgl +*,*5ukjsuu- fhu :syripetal and tangential accyfu-j,m:lus+ka *,g * huxu s5eleration?

  The gravitational force between two objects is propormu /j / ,sksr7swn)h,ztional to

  The gravitational force between two objects is inversely pa2 s4dnk 8fap0roportional to

  Two objects attract each other gravitationally. If the distance between theiz5ary44ef5,ke o4zn hr ckaef5hnr4z, y4 eoz54enters is cut in half, the gravitational force

  Two objects, with massey6 l4rmy45rb 0e lmw6es $m_{1}$ 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 lt0x0;oalq4jg+ p i2y$m_{1}$ 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 )ksjh*f 4ved/gravitation.

  Compared to its mass on the Earth, the mass of an object on th sux/j io,w2fmp//7 nee Moon is

  The acceleration of gravity on the Moon is one-sixth what italqbz2 x +2f4c is on Earth. An objecafxcl422b z +qt of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's su,tiyxx e+/.y nrface, the rocket's weight

  A spaceship is traveling to the Moon. At w*8 n(kgq*jpvwhat point is it beyond the pull of Earth's g(q*pwkvg8 *n jravity?

  Suppose a satellite were orbiting the Earth just vkgppf w l:5a;mm+ uxi84rk*x n r+t10above the surface. What is its centraxk krf+p+xwm* 0un4 rtg8l15 mpiv:;ipetal acceleration?

  A hypothetical planet has a mass of had8w ;ug)5 fgevlf that of the Earth and a radius of twice that of the Earth. What is the acceleration due gg)vwd5ef8u; to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on thl :pk3x +m,mhfxh1 g:il) w8tze Moon is one-sixth what it is on Earth. The radius of the Moon ilm xp3 x,):ilgz+kthmh:81wf s one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twicrq7wt2j65alp c db53te the radius of planet A. If planet A has mass m, what is the mass of planet57 52 atpjdqcw trlb63 B?

  Two planets have the same sur nfafsql7q6k7pg7v 4/face gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is pv 7lq7fnk7 s6q/4gfa the radius of planet B?

  Consider a small satellite moving in a circular 5dh3irc9i:pmxn1r,(m4 mwsn orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's pr3hciw,5:dn rsm91m inm(4x orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in cu2z 6;sa:n4me5n)ae5eqvu1on0ja +x,x jdythe same orbit. Compare the two satellite's speeds.eqxd:anm6nyv;4xzjo12)+ne s ,a 05auc 5jeu

  A person is standing on a scale in an elevator accelerating di 1fm3o7 p; z,ygjw im:rekg5+ :2znazownward. Compare the reading on the scale to the person's true weig:g, j+:znw mz21y rfmiizg5 3ao;epk7ht.

  Who was the first person to realize that the planets move i0/x,fqhy3e3 .e rrqn pe54vazn elliptical paths arournfxhqzy3r/ 4ae5e e3 .q p,v0nd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbim )bmv lgxcnj8b((fas(+,4e86 bpguj t around the Sux( +,a8sf4 bb8v lbu)6c gn(pjj(gmemn,

  Let the average orbital radi )x7gc7a ( 4w7qhlkas:qz m.hmus of a planet be R. Let the orbital period be T. What quantity is constant for all:7 lkc7(m w7.xahmz4qhs)agq planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wiv*4sl4jbdcxbds3 ( u /th 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*4b(jd/su 3bc xvdls 4 of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Eart 4/fn fv +s9.oxqffk kpe./ot+h 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 kqot. np+fkof9fx+ /s4evf / .distance from the Sun?

State Kepler's laws.;z y 80m3cbvbv

  List the four fundamental forces in h1i76-9u j3(pf6 l4 j(todlquoploqx nature.

  An object moves with a constant speed of 30 m/s on a c,.*ijf)-o6al611 nhn w8vba:w g3cy zoi di gdircular track of radius 150 m. What is the accelinow az6gdiwh l,.1 )af:ny* 136 bidc8oj-gveration of the object?

  The maximum speed around a level curve is 30.0 kb- l5qss qb:*tm/h. What is the maximum speed around a curve qqs5b*tbl - :swith twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on twr 73 g5df 1nbd4df5uahe perimeter of a bicycle wheel of diameter 70 cm when f3da5w7un1g 5r fddb4the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m fromoz 9dq-so*xk2 the axis. What is thex9qzodk-o *2s centripetal acceleration?

  How many revolutions per minute mu8yasmsb.y 2yc; +1pykst a circular, rotating space station of radius 1000 m rotate to prodkac1y.s+ys yy;b pm8 2uce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1chso 2bb)dsh13ajr pn+, vh84 3.7 m radius turn at 96.5 km/h. What is the centripetal f) 8b,jh h12p bvdca4n+s3 horsorce on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirl, 8sswd coihw6*t0mp*ed in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maxish6mdwi0,w poc*8 s *tmum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong strin xyvlc9w1,nd2c b0gm;g 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 stol1 bn, ygm d0xcw92vc;ne's speed at this point is given by

  A stone, of mass m, is attached toapz(mc65m9*o ia2 itz 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 weight. The stone's speed at this p ai5*2o6a mmztc(zi9point is given by

  A jet plane flying 60+z sltcmda5xs8,g 43z0 m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature x4z,+ldgs c 3 ma8z5stof the loop in which the plane is flying?

  A pilot makes an outside f r l2(kz6eu9z 5bcu2(eq59ihi)bvja vertical 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 2lb9j 5ruq2 6 (kivazhfc)(ze bu5ie9 with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is aboun:gewm 6it2i zq)2)ni t seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolwi6e :q 2zimn2))intg erate at a speed of 250 m/s?

  A car traveling 20 m/s rounds a :dpqj3v57j7tbotfz ,n 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the samj5obvp tj3d7 z:7ft q,e coefficient of friction between the car's tires and each road surface.)

  A car is negotiating araet 2oe4hz5: flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided rt2:h4o5a ze eby 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 a1 /y02 bhs swz)x7lv,wg/pvmr speed of 14 m/s. What must be the minimum coefficient of friction ,xz1hyvwg/ws 0 /v)7rls bmp2between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a le*gip6a+pcf g f)i4gd1vel curve. The coefficient of friction between the tires and the rogc6i+p*p4gf df a)ig1ad 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 an Olympic bobsled to negotiate a 100 zu-x3n-m7r3fg;6jbux8c oz p-m radig7ur z- 6of zj3mp;bucx nx83-us turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a :j0q.*f:2gpw3 mr zfw kh y.dq$45^{\circ}$ 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 o g0881pebfux:gxmr8 at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankmi+3c vl0:ziy3qi4/0l ljf wjed 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 horizontx c*(5/pjk mh/ho, zyjal circle of radiu/y *hp/oj, x(zj5 ckhms 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 acci, xned3 p0 y2jjj1w-ezda06delerates 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 value in the blank0jdwx3j- 06i z peaynd d21j,es)
(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 mass;igsdhun.t4yfj5a9 ( h4) (k n bux1 epd5zk.u $1.67 \times 10^{-27} \; kg$ 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 Earth, dlq e--kjnz/w47dp6bhue to the Moon? The mass of thz4-hpk/d b7we 6qj -lne 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 massek3 6al4baf.biccr cg(,tsd )h e*gl 2:1;iz pgs are moved to half of their initial distance, what is the gravitational attractive force?a ipz1lcb6 g* cbl:2hfa, 4;t (g.sgr3c)ikde

  For a spacecraft going from the Earth toward the Sun, at luubloqrb bez*p8 9c97r;u9b)j; n b; what distance from the Earth will the gravitational forces due to the Sun and the Eal9o lb9bu;u)*pn eqbr; z c7b 8u;rj9brth 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 ;mon*ou,b,.0 clt ud0mts yx+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 a "space-walk" at a distv y3kbm il9dxy76n* o8ance above the Earth equal to the ra* 7mklxy8iybov3dn69dius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface6c g:el edk6p, will the acceleration of gravity e6decgkp,: l6 be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its suz lm;mev902 csiz)rcbv j*5o.k6:sbirface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to thz02brbomljsm* 6c):.i icv;e v59k sze acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gravizn4c pzr97 (rvty i(rp9rvzz7cn 4s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 th keyx0(zaq9c 7y(e vb*.nhqr+ p4 *qN on the surface 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 its weighk(4 n. eypa**+y0v qrqcx 9tqb(z hhe7t?

  By how many newtons does the weight of a 100-kg person ch bjoc2fb lq6,-ange when he goes from sea level to an altitude of 5000 mq bcl 2-6b,ofj? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satelly hj o.tdcd889m- sun4ite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's84j- tmsduon h.d98cy weight?

  A spherically symmetric planet has four times the Earth's mass and twic u p .aeq-;lqu u;7bd84sw;ewoe(lo b/ot9z5k e its radius. If a jar of peanut e;k loq/w;- osluz ;u.bwedatoq(b ue 4p5798butter weighs 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, Earth, and Sun all lie on the sspngxf8 ; m: or31 -l6ozkjlg-o+0uso2 eeva: ame line, with the Earth between the Moon and the Sun. The Moon has + zk u-f1s0 3pe-gv lr2:om:;8ajngolos6xe o 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 transportzyce;8fezd b-t1 7he 0ed 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 circulalnc+e.(foe6r9 ;+m7 xs+cx rrfza i;br orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Eoc+frib6 ( eez xm+ 79xn;+rar c.;fslarth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aboub+mf(quamz . 6t 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 mean radiubfm.+( mqau 6zs of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circula kbi.eglxsl 0;50hck 5r orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Ear.s; cl5b5l0xghi0k ekth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamete4sf*bbh; q7yer 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 radi/fuhn 71d5p05qg odveus 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 t.urrs i.2 ,h1az2bkmorbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How loasrum r. ,ib1tz .h2k2ng does it take moon B to complete an orbit?

  The planet Jupiter is +p,)zexq c 8ds -fgxh6xi .(jq$7.78 \times 10^{11} \; m$ 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 Jupitebg2ha w-yol l(vjbizw,*b. agl v-,(+r 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distan-a, b-y2bbilvl vg(gwz+hw l(o.a *j,ce from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)