Is it possible for an object moving with a cofbfdby5e0sf ; jf3 1csd4, 4vhnstant speed to accelerate? Explai ,50ef3b fs14 bcj4f;fsyhdvd n.

  Consider a particle moving with constant speed such th)lm*6o ,yq-oe07gt7.x0xam0 r7apfq xltyl gat its acceleration of constant magnitude is alwala0yr)q po gx6oa f07lem,t0.7l7 *yqgm-xtxys perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dir4ul t(arxh9 (eection of the object's 49 h((ruaeltxvelocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of thx;s8x 9yyx0u dl:kk;*ptle3ve acceleratiyx 9v0 p3kx l; t;d*usyexl:8kon is

  Consider a particle moving with constant sg( f lylj5(ff9peed such that its acceleration of constant magnitude is always perpendicular to ( jfy9fl fg5l(its velocity.

  What type of acceleration does an object moving wiw8 ralciu/ed+) mh-a (th constant speed in a circular d( /uwmir8+ a-a lehc)path experience?

  What force is needed to make an object move in cq/df wv1 6vb/a circle?

  When an object experienc+7mthhtq -x)/jw*a k bes uniform circular motion, the direction of the net forcht)qj+ abkwtxhm -7/*e is

  A roller coaster car is on a trawvl0b92 w1 o-j/jfaqymohc eg; 2m4x7ck that forms a circular loop in the vertical plane. If the car is to just maintain contact with tfoh;wb2 o4- e9lmm j17c2vxj /agw0yq rack 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 )n5u n+ma) eq7(jme3 vcie,yc that forms a circular loop (radius = r) in the vertica(e5yjemeqn7i +m,ca) 3u n)c vl 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 foll8n-1yl0sfaug 0o q0a ncln. (fows a semi-circular arc until it is going strai8 0-afc l(unal.fnyso0gnq0 1ght 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 ofda:86*,9 d meg asimvn 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. Thensmsyw 040zt:w 7 vejj, it goes around the same curve at half of the origijj0w :s, wm ye4s70ztvnal 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 constant speed v. Then it goes avzevt4 -urn0) g28gqmh5ept d47u ri)round a curve of radius 2r at speed 2v. Whatmig-08)n7getp5q ) d uur4v rhzev 42t 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 with speer6.g2bx g tbhp9v2q+b d v. If the road is frictionless due to ice, the car can still negotiate the curq6b xb b2.grp9v h+tg2ve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves o6y x8, lvwei3bn a bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (nbi, wxy8 vl3e6o 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 turn on the Olympic bobsled track is not constanta9h1a3uftxi 3v /x1ss, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower com/ax1s93 13h tvxiu safing out of the turn. Why do they do this?

  Is it possible for an objectb7s-w9c 8ac*v: xa)q( 2loaslfy n-lb moving around a circular path to have both centripetal and tangential accelera-w (c a8:sa l2)cv*bsl-7qyf xal9bontion?

  The gravitational force between two objects is p: s7x0-kb 8 r )3giz+kues xtugiucw0z-nc 3k*roportional to

  The gravitational force between two objectsnj6ykjs 9c73c is inversely proportional to

  Two objects attract each other gravita+oxeq q: hlmf- y4b.6uo++hlptionally. If the distance between their centers is cut in half, the gravitational folxh6 :+qu+hfl om bpq4 +.eo-yrce

  Two objects, with mass.,:tc bd*atxvmlk yr lx44ga*-cnf30 es $m_{1}$ 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 massea 5n8nuq;qi :v4jzcj4d8qj 3ws $m_{1}$ 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 gravitation. whk1agjgiy m -p(ym sqbk42*,9(z d2z

  Compared to its mass on the Earth, the mass of an object on them c2c(n m2a5s8giq 12s, mkdzm Moon is

  The acceleration of grav -m+4zcf j4zxh8 dnyj6ity on the Moon is one-sixth what it is on Earth. An objectm z6j+y-zjxf8nh4d4 c of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surf;qo51 ljh-al rl 7(zgface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull of 14 cib(s:8qb(pphm,x yl5u1 vuh3jfqEarth's gm 14(uq5hbulbh(fyx,p31vqs j ci p:8ravity?

  Suppose a satellite were oe63btgrec33 1xrgu.u kt0z6frbiting the Earth just above the surface. What is its centripetal t3b3 tfk0u. g ru663zeex1grcacceleration?

  A hypothetical plane yxlzo3b em xke27/9( ))sbihjt has a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to graviel /(zk 2 eybo9xih)bj)xms3 7ty at the Earth?

  The acceleration of gravity on the Moon is one-sixth 9h/a j1ici+ kkwhat it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earthji9+i k1h kca/'s?

  Two planets have the sa jjd6evh 22cvp:0.t gime surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, wh 0h2j2dp give6 vc:t.jat is the mass of planet B?

  Two planets have the same ur 9 /t8rgt(4y szrihg;o(k6c surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, r4g/ tg8(kt;r6osy hicr9(zu what is the radius of planet B?

  Consider a small satellite moving in a circuf 7 it:;8g1iatef *upxlar orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's or:f x g;eiuit7fa 81p*tbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbil-wv ac9morbl2c :d36 t. Compare the two satelll-wmbodl:r9 6c2c3a vite's speeds.

  A person is standing on a snsp vq2zm y87+ meb)s)cale in an elevator accelerating downward. Compare thb q yspm8v)nz2e s)+7me reading on the scale to the person's true weight.

  Who was the first person to realize that the planti7u2ty h6 q(xets move in elliptical paths arountq 2t6uy 7h(ixd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit aroundu-ggdr)bb2:stf3xd;h6 lti g/+;vpk the Sug2-u kg g;rbhp l)dt 3vx:; dsb/+6ftin,

  Let the average orbital radius of a planet be R. Let the orbital periu ,-s*3b:juxiywm 8qw g3cv)qod be T. What quantity is constant for all planets orbiting the S8c w3 by)uw,j3 q giqs-mu*vx:un?

  A planet is discovered to orbit xtjbvh n;k/*gm9j16 earound a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our S ebkh*6mg nj ;/1j9xtvun. 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 period?

  The average distance fromowc bh 4m sp1q,zy+l)9 the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-thirdz4h9+lpb)m, w1 coysq of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.hb +z;v yu01hr24vf xg

  List the four fundamental forces in natuia h +).* lwfffxz40bnre.

  An object moves with a constant speed of 30 m/sk0/ lljh9q8 8tz/ nh7pgo*s ffqbx40 v on a circular track of radius 150 m. What is the acceleration of jgqbns/ 9h8*zhf/ 0pql7o8vl0kfxt4the object?

  The maximum speed around a level curve is x7b 3sof )on/fj)l trj*(b)wk 30.0 km/h. What is the maximum speed around a curve wi (fw*)x/ toj jlf )br3obnk7)sth twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point gy uupr*2l/in36n v) con the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.6*nrn2 3giu p c/ulyv)0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0dtq*o l42l uhmu55f;a r5z 7cw.200 m from the axis. What is the centripetal accelerat2;o5rlz745cmu aul w*d t fhq5ion?

  How many revolutions per minute must a circular, rotatuaar o)z93v3ez+ie j /k2z lgi.lup+8 ing space station of radius 1 3/zlp.93)keuaiz2z ++vjleugoai 8r 000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a cjo.knboht *1lsb ;ta+s)(3k 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the hn31 )jb(aot.s okk;st+* c lbmotorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirledxe1xe9xf;s4 n in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is not e4xx1n;efx9s to break?

  A stone, of mass m, is attached to a strong string 0 0 h/ ql6bzutf4c*cneand 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 weun/ zfl0e0c46* tq cbhight. 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 vertical cir7gq)d)a l6ldccle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's wdd6)7lgq lc )aeight. The stone's speed at this point is given by

  A jet plane flying 600 m/s expesz kz9poc 5x48ps n 03d14lwgfriences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of lzop w35s 41pkx0f9n8 c4gdszthe loop in which the plane is flying?

  A pilot makes an outside vertical lga-fs( b2rgm qv*2 g1hp39uekoop (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 normal weight. How fast is he age*s r( gbh9qum22 gpk1-f3vgoing?

  The maximum force a pilot can stand is about ptpk f)t :7d 7mmd;q,zmtn9e7 seven times his weight. What is the mini7pm7;)meq:pt z, d9 7kmtdnftmum radius of curvature 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-mldyobv.b) pwom6) r:h*te.me3 mm 1kxov/ 5c/ radius horizontal curve with the tires on the verge of slipping. How fast can this car round a secon.od) mb/v:et3om)r / p *bwyo5kxe1lhv6m cm.d 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 curvjk .8ucoe65cue of radius 50 m with a speed of 20 m/s. The centripetal force provided by friction .5ujecu8o ck6is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radi g 0j2qkqgxxldu/4w;*us 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction betwek/gqg* u ;ld42q0wx xjen 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 coefficif:rr8po75 razent of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay onozr f7a8: r5rp the road?

  What minimum banking angle is required for an Olympic bobslem,v 58lis 1d0we di/shd to negotiate a 100-m radiudw08lsv/, dsi hi1em5s turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked yy e 97* tpk*9,xtiw,u)uyng8pm6hm zat 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 radius8mgnvmq91l t; 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 at(9jc 3wrf0f ,oz6o*kyyc mu 4r $45^{\circ}$. 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 whx 4jxvdq:lqq :0stncju-3 h8-w j.04v/ sqtrevolving uniformly in a horizontal circle of radiu q:0j-scww .quxvtx h30h/t8j qdjq-lnv:44s s 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 /hir-* gj9ugkcar accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only filrgguih-j /k9*l 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 mam7 cy5eb*bo )xss $1.67 \times 10^{-27} \; kg$ 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 7 /bn+s/ wo:7v5 j2esvtwyvbs8 0-kg person standing on the Earth, due to the Moo7v:8 s5/e+ bswvy2vb nwsjto/n? 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 attraccjso 0p3cwx56i9a v 70u;ybgltive force between two masses is F. If the masses are moved to half of their initial distance, whatcyl3iu9b op0xg 0s 7vcawj;65 is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at w8 y f0:0) 9e2b8 ijtfp bz4gjhkpwt)lphat distance from the Earth will the gravitational forces due to thkh )bf288 pf9) p 0y pj0j:b4iwetlztge 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 i x:k46qu f5zb4ntsc8e c-1yjus $7.4 \times 10^{22} \; kg$ 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 "s6yn8 o/hmx)dn pace-walk" at a distance above the Earth equal to the radxnm6h n/ oy8)dius of the Earth. What is her acceleration due to gravity?

  The radius of the Eart4.p kv b1pkvw7h is R. At what distance above the Earth's surface will the acceleration of gravity bb1kvv4pp7. kw e $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surf bf.p jyd7:t0face equal to 3 times the radius of Mars. f df jt.07p:byThe acceleration 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 some planet1 dl:hbssnf8- avdy)+'s center, the acceleration of gravity i -ad sn h)d+1sbvl:fy8s $32 \; m/s^2$. 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 tp75qhr m5hzk n5f60rz x zs31p d7auv(he Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surk 5zz5d xh7ruf 6shqmz7pv3( 5pn10arface, what is its weight?

  By how many newtons does the w,gapv1rl r wi9j1:+a/ (srtaseight of a 100-kg person change when he goes from sea level to an altrai+s / 1,r lwavg(:sjr a91ptitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A fz a*v7:inb(1a ly5kvsatellite of mass 100 kg is at a point 3r above the Earth's surface. Whana iz5l:7(y1 vak* bfvt is the satellite's weight?

  A spherically symmetric pl+, g .q4n myu0*cnb -qal*6qwzgiwko0 anet has four times 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 4w q zau+*qngnb. w0cg6qy -*,ok0lim would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie g0;t;48yfr :rvofsmdw er5r,on the same line, with the Earth between the Moon and the Sun. The Moon hegm;ysrr:w8,t;o5rd ffv 4 r0as 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 rqcjv 6),rr5ais transported 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.,x-18 v3yz2ivjf4hf ay it just skims the surface of the Earth). What is the speed of the satellite? (The mean radiua 42vh-v8f1zx3j fiyy s of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aw+kes2-,;vf lyxxt n ,bout the Earth (i.e., it just skims the surface of the Earth). How long does it takstwk+e,vl2-n x f; ,xye to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circulrrn f k-ei8k5vx:3o2e3(ms7sw3bxqz ar 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 Earth? (The mean radius of the Earth 5 7eex 3wkn2bs-xf3(z3m:vrkro iq8 sis $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametevl;5rkcom ad a9:w 7a-r 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 f45x:ahr-p: q0sdd n--konpg 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 orl.o9o * mn cdeyjee+ ww9g/)y0bits. 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 it take moon B to complete an oyewj* +egclwmo0)y e99 . d/norbit?

  The planet Jupiter is 0cd bb )sub.oetqv7q i 0,ha3-r)*uns$7.78 \times 10^{11} \; m$ 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 Jupiterhf(dk* vthc2* 12 years to orbit the Sun once. What is the average distance from Jupiter to th(k h2 d*fv*hcte Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)