Is it possible for an objedx+wuli p: h i-3s 62rbw);cract moving with a constant speed to accelerate? Explain -rh )+2d 3w6csi wi:urb;paxl.

  Consider a particle moving with constant speed such that ae p na(gw/ sc1z:r:y:its acceleration of constant sn1acy:zw:ar /( eg:pmagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dire8u84 ucmjjg9euot h+-2yfzn:ction of the object's veloceug:un+ - 829mf 8ytzh u4jojcity and acceleration vectors.

  When an object experiences uniform circular motiouycwywj1ts-e3 4 ))a jn, the direction of the acceleratiwj a1csu-t )w4jye y)3on is

  Consider a particle moving with constant speed such that its accec,d:,k qs;n( s g*erfhleration of constant magnitude is always perpendicular to its ve(n *qf,s skhg;red,:clocity.

  What type of acceleration do)o9v tuwr)- ;*wjb*m0f fbw wby5jbw7es an object moving with constant speed in a circular path experieb)*t wwm;*wfbufyr 0jvo )w597w-b b jnce?

  What force is needed to make an object move in al 3 u k :hcwq9(y,)y-nkgfcjx sg,w(h- circle?

  When an object experiences uniform circular motion, calx+ 0 xeoy3+p89oy9o lhf3rthe direction of the net for 93aor8ohol39f+lx+yey xc p0ce is

  A roller coaster car is on a track that forms a circular lo:-2fbu uwce2gwgp*ebk - w51 qop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, whatwpg-u:kb1cewfueq2 wg-2b*5 is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a cirm n:6 px3sxe:acular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the tx:e:m snapx 63rack at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a veie il2a 7/;b*ny4 ulsvrtical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on himlv ys e;lu/4ibn* 2a7i 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 curvr 0xs8+)uptr we of 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. Then it5* xz 3(o/s7*ed9 )dgzlwztzhr.b m yh goes around hy .w)d dt*s73 *zgzxeobz5/zr( 9mlhthe 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, compared to the first time?

  A car goes around a curve of ra d8o.qw4, )ha hg1fxzwdius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. Wh a8hx)oqwhf ,41wgdz.at 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 bank23ehe/ chl5 mhed curve of radius 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 from the road is equal in magni/h3h 2h5cem eltude to

  Two horizontal curves on a bobsl enwvde ut:9/1ed run are banked at the same angle, but one has t:vn/euw9te1 d wice 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 speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not const9vvakq0al ku xz(1l;4(l nn6nant, but increases upward unk41 vl0nal( 6k9xqa nl(;v zfrom 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 object 1opm:vks vhj(cj0m 94 moving around a circular path to have both centripetal and tangential accelerationvhm 4m 10kscjv(po j:9?

  The gravitational force between two objects is proporhho:j37zokym5/ jeq1hww(k /h :bki/ao(1 sttional to

  The gravitational force xy6tff.b;0t mbetween two objects is inversely proportional to

  Two objects attract each other gravitational(;3coai u, *egb q5n:5 wyhubuly. If the distance between their centers is cut in half, the gravita3 55by(;eauon w:bchi* ug ,qutional force

  Two objects, with ma0ox gvg781 f7q 0l;/hn6lz uidl.ujr qsses $m_{1}$ 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 massesg(*f/9e yru-rxe ser9 $m_{1}$ 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.5yo( ;*rm setyvl f2f-

  Compared to its mass on the Earth, the mass of an object on the Moon zde -zj48i 7spis

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An obzo s 1wf/x-3a0 pjckl9jectz-soa3 jf/c0 1pk 9wxl of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's smw )o7cr :0vksurface, the rocket's weight

  A spaceship is traveling to the Moon. Aev;ijvqmzv z*sgd6n7-13x c- t what point is it beyond the pull of Earth's gravity?v3id-zjn6x-*7egvs ;q c1vzm

  Suppose a satellite were orbiting theyei* qul o2cn1c 8,h*w Earth just above the surface. What is its centripetal accelerationnq ,2 wlcucy*1oh8*ie ?

  A hypothetical planet has a mass of half that of the Earth and a radius of twio3omd*;f ur ;oce that o;o;oud*omfr 3 f the Earth. What is 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 it ish/ 5l6pas2, cad)vnij on Earth. The radius of 62lcs/nap adhi 5),vjthe Moon is 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 plaq94ggj) fxr )* 7lwpwbjublp0l 13r7wnet B has twice the radius of planet A. If planet A has mass m, what is tg 47lxrjru)gqlb)p wpw9w7bj1 30l * fhe mass of planet B?

  Two planets have the same surface gravity, but planet 7l/lag.(k/7l tn6t2zhfg j5 uk x/pni B has twice the mass of planet A. If plg zai7 p (k5.j2 6lunxg/l/7hlk/tntfanet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circulah 42ysj-ueau5r orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital velo 2e-j shy4ua5ucity?

  Satellite A has twice the mass of satellite B, and ro00kc3 8pql8 l ,unnvuhj 3l(sqtates in the same orbit. Compare the two satellite's sp vls883qun0h3kn0lcj uql ( ,peeds.

  A person is standing on a scale in an elevator accelerating downward. Compare 8b wwtlf,/4r:vmj*e k the reading on the scale to thewmerkbt ,v*:w4 lfj8/ person's true weight.

  Who was the first person to realize that the planets move in ell-0:;qtm p ne2nw+vgn giptical paths aroum2ggw ne -0n;nq pt+v:nd the Sun?

  The speed of Halley's Comet, while travel-j.* y0tbp-j: zgfmqogtl cr:j0kf b9i:,/mring in its elliptical orbit around the Su::,rbf:j lbg-my-ijz0 oft/kqg.c9 p*m 0jrt n,

  Let the average orbital radius of a planet beb6 :jhwx r(;hh R. Let the orbital period be T. What quantity is constant for all (6rhw;:bxh jhplanets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromedn d*x,lym 9 hgau4nsd/. oo/8xa, with the same orbital diameter as the Earth around o,s *axld9ud hn8x4m ./gyo on/ur Sun. 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 from the Earth to the Sun is ner 3go,cg m05defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from , reg cog350mnthe Sun?

State Kepler's laws.cyuy0g2(7qt3h, / cxxbj wi 1o

  List the four fundamental forc:wr/d/ gilft:+ff 2 4nbnb yx0es in nature.

  An object moves with a constant speed of 30 m/s)xt,gt (oiny a i:+n93 3,lfui)eyyg v on a circular track of radius 150 m. What is the accelerationt3ni+3yeu,ay :(,oxg ) fitg )9ylinv of the object?

  The maximum speed around m(7x4: ky jmwpsxmzu l4 7y7*ia level curve is 30.0 km/h. What is the maximum speed around a curve with twicej ykx:my7m4sl uwpxz4* (7i7m the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on sx0m*q qcg:.hthe perimeter of a bicycle wheel of diameter 70 cm when the s g.*xmq 0q:hcbike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from thehy 0e07 rm8r9notvp8q axis. What is the centripetal n9ot 80h7qyremp08r vacceleration?

  How many revolutions per minute must a circular, rotating spa-xe6ywabi0 o7klbi:2;;zkqo ce station of radius 1000 m rotat lk wi 2;k-ai6y:bozb0o7qe;xe to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes agsfcrf ;6s()u38e iefround a 13.7 m radius turn at 96.5 km/h. What is the centripetal force onf ce3s e uf;)8s(fgir6 the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Thewnf 0or9 v0/dw system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maxf9nr0o/ 0dw wvimum speed of the mass if the string is not to break?

  A stone, of mass m, is attacp4ql7kf xctkp f*0./thed to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the ten0l q.f*ptkkxc47t/fp sion 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 whirl *7dl(9klvydlyx3vj 7:wy s 1:wzg:lbed in a vertical circle of radius r. At the exact l wxkl9 y*v1gyws 3:7yjbz(:ld7vdl :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 m6/vxjo.lmh xm ;in9g1i rny07/s experiences an acceleration of 4g when pulling out of the dive.miv0/igr h;l ym7xj16nxo 9n . What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which t4d gm9 ow1 a:cyw2cpq3he center of the loop is beneath him) of radius 3200 m. At the top of hi1do2qwg :cpy am9w 4c3s 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 p s9k*ae33bra uilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speeuk3ab*a9e3s rd of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radin+ w7-m3hiq dxus horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume 3+mdhw-x7 qni 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 s3zq6y r3f b,vv/g3m z b5/qylm/s. The centripetal force provided by fricti,lv fyy6 z5qbb r3/g/ms3q3 vzon is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of ra;0jv owrwyn).dius 50 m at a speed of 14 m/s. What must be the minimum coefficient of frio)jyr w;nvw.0 ction 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 cur*ym 2fdu9 7,x5h1m3rybdip9*rs a m olve. The coefficient of friction between the tires and the road is 0.40. What is the minimum3m97r moh2b*apx15rmy,dl*difs y u9 radius of the curve if the car is to stay on the road?

  What minimum banking angle is requi* 2iw;bwh yukc ,bt 5p)wah:)zred for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s withoutb kwz: tw2*;ubhpi5) chwa,)y skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is ban2o3 )xf8nwruc i.fv9 sked 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 radius 100 m, banked at an angl)/+sd rb1h0+ k n/gu7bseenxee of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bank1c pi,d;oy+uif qfszyz*m* mit l:4 37ed 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 uniz 73ylh(4vkbmformly in a horizontal circ yl hv3bzm4k(7le 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, a race car accelerates yozdbcc2m4 .6lbep:1at 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 6ocmzb2bep1. d cl 4y: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 prot t j(p*cp;*.li-fk q emgzxc:6on 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 f0oqk)e fb764rc1bd f6x9asz on a 70-kg person standing on the Earth, due to the b0z s9qdfx k 4) f66rc1e7bafoMoon? 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 thmuv28 f;rwgcet a7 sn;:dw2j: e masses are moved to half of their initial distance, what is the gravitational at aj; twr8wefvgd 2:7n2mu:;sctractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance fro( s6*j)5ly+)pn k x8)xzjfh bdd1bi 2ijnrlj/m the Earth will the gravitation fp6k dnilxljx) hbs+njj1jy iz)r)d25/8(b *al forces 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 is j jgl v* 4tdvv1-42oemj :qe+t$7.4 \times 10^{22} \; kg$ 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 above the Ea7f,ujagj* u,7iv zntmq a/i8,rth equal to the radius of the Earth. What is tam*8iqnjz,ij,va7u f/7u,g her acceleration due to gravity?

  The radius of the Earth is R. At what distan(on p9 dg61bpwce above the Earth's surface will the acceler gpon9(b6dp1wation of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dis tmy7tkuaca ;20s 9s ut+yaw*1tance above its surface equal to 3 times the radius of May1uk* a +tm27 cys0w9taus; tars. The 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 planet's center, the acceleration of gr /vn/0 iyt,psmavity is t/,psmv y /in0$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface ouce997 cwj-r 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 weir- jw9 e7co9ucght?

  By how many newtons does th1lg gt d,./ ijlh.:qo/cr(dqye weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean r,:/ro1i hq tl gdqdjl.c(y. /gadius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a poi zyn3eg2 jvn 3g.my2f:nt 3r above the Earth's surface. What is the satel3 :ym zey22 j3.nngfgvlite's weight?

  A spherically symmetric planet has four timwv7;:uj0ni 05 f+vun q lauqc8es the Earth's mass and twice its radiu0qv c 8l7iw+vjn 5qu0;:anuf us. If a jar of peanut butter 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 same line, with h*0 ;r l*4o fdo,bocxsthe Earth between the Moon and the Sun. The Moo* f0 ;lhd*oxc,ro4sbo n 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 isl( zfn()n9tyycp .t 4h 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 orbitsi39 6x 1rb(vn sp9ukq about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satekvq 9px s9u(in6s3 1brllite? (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., kw;nmd72jx vc5m -t,;ic4tu bit just skims the surface of the Earth). How long does it take to make one revolution aroundn w;5ub;cjtxi d-74tm k2 ,mcv the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in ci2a r 1aizsagv:+kf7 y7rcular orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of thea7zkiy: g +2a 1sv7far Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Juja2 m(-,kot*ir uj 7njpiter, 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 zy2v 6om ta3* p02xur;s d,khw 1gqji-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 circulag6y 0i91zl plar orbits. Moon A has orbital radius r, paz9 1y 6gl0liand 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 orbit?

  The planet Jupiter is g(n ac /( y2x,fktqm(9gssxb6 $7.78 \times 10^{11} \; m$ 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 orbitg)dq zed 1) 7l)u6jmpn the Sun once. What is the average distance from Jupiterlme nqj )1p dz)76)dgu to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)