Is it possible for an object mov e*-sg;j4 eltqing with a constant speed to accelerate? Explaits *;-eel qjg4n.

  Consider a particle moving with constant speed+ rnqsyop+1n 4 such that its acceleration of constant magnitude is always perpendicular y4ons+q n 1+rpto its velocity.

  An object moves in a circular path at a k7tuuy lj310ta/pc sew4e9/gconstant speed. Compare the direction of the object's velocik1 ey4pl7utew3 /c s9ua/0tg jty and acceleration vectors.

  When an object experiences fxam 8i9+p0nguniform circular motion, the direction of the acceleration is 98 ig0nmf+axp

  Consider a particle moving with constant speed such that its w9t4 q(0xnl1psa9i ,wwy9cec acceleration of constant magnitude is always perptcxn9w 49a 0 iwp9,(wl1cqeysendicular to its velocity.

  What type of acceleration does an object moving with ceuc./hk8( ks konstant speed in a circular path k8(sueh.c/k kexperience?

  What force is needed to make an 62x*th ch* kxlqv1, unltl.*oobject move in a circle?

  When an object experiences unvj n01 accv:1aiform circular motion, the direction of the net for n:vavjca1 c10ce is

  A roller coaster car is on a track th+x)cd og8xvv i2lhw:1at forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top gxow2l)d8+icvv 1xh: 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 c0vvfihjsk mvtj,;y,+ :dn 9t+ ircular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track s vjnfv, +:iyd+tk;vh,09mt jat the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then followsn/80rgo- tdvo a semi-circular arc until it is going straight up. Just as the plane iotr/ o8n vg0d-s 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 curm gw1c 5+y2meive 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 conswiy wmm x2)m 08vz2c2ztant speed v. Then it goes around the same curve mmvcz wwix)0222 mzy8 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 radius r at a c r*hdfs amh63dpt( 2e b*nojy9ki(t5) onstant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the p)k*96bd if ae5rmsdto ((3 njt yh2*hsecond curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If the rbo9 bt6j sq+3dvy2 /aeoad is frictionless due to ic e63b+oa2/qj dv9 btsye, 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 ad 5 c,,iu-jcpire banked at the same angle, but one has twice the ra5cpicju , -di,dius 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 constuc lr7frf9 +36 aw+xshant, but increases upward from the horizontal. Coming around a turn, the bob7xc +hflf+ra3rwu9 6ssled 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 movt* +tm+/bizad/5f jy4ixij+uing around a circular path to have both centripetal and tangential acceleratii fji/5x+4z*/by ttuim+d a+ jon?

  The gravitational force between two objects is proportional 0l(u9nyrd 5 bsto

  The gravitational force between two objects is inverse4 z m.vqnb/(uw)ub7rely proportional to

  Two objects attract each other gravitationazgns*0eluw3 2 w)/fd ally. If the distance between their centers is cut in h 0a f)e/*u3z2nsgwdlwalf, the gravitational force

  Two objects, with masses 6e2rjtf:v:mwor yvf+06 s4 y z$m_{1}$ 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 massesihc23mxr2ju7 7u sr v9 $m_{1}$ 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 q 7w ft8(pp9:lnlgrs)l5ni4m.f65i+jkrel e gravitation.

  Compared to its mass on the Earth, the mass of an object on t m 4bvw66gspf8bg+ita:ybrg r*m8*d7he Moon is

  The acceleration of gravity on the Moon is kwmwwnqf;290 c p2:ow one-sixth what it is on Earth. An objn2 q:f2wo9c0wp; kww mect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'q,/6hqhqsn: 8v)+ixq jw4fsn s surface, the rocket's weight

  A spaceship is traveling to the Moonzc9xz:w3ditbe 4,)kg*8 c+au/a ucqf . At what point is it beyond the pull of Earth's u,xe:c/ c3 gwu)8*bdqa49zaik zt +f cgravity?

  Suppose a satellite were orbiting the Earth just above the surface. Wharxlz . 7a g.g af1(,licb2c(ugt is its centripetal accelerat.xg((2,gfa bgi7llcc 1rau.zion?

  A hypothetical planet has a mass of half that of the Earth ayx(3z:d1 ygzz3p/d nxr8:zy snd 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 gravi3s1:3ydryzg: x z y( pzxn/d8zty at the Earth?

  The acceleration of gravity on the Moon is one-si3gre ih /h+1mmxth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass comph +m gri/13emhared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius m:+5j2yy+eazy +-jgw6xtapiof planet A. If planet A has mass m, what is the magip-zea j+:++wy6y5 2tmjaxy ss of planet B?

  Two planets have the same surface grav,6oj :ag5suz,45 y)dv31ib wlzhq w+ufdmxs; ity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet B h;xgu d)1 ,abjqwi4d:v+u56fw3 slm z5o,syz?

  Consider a small satellite moving in a circular orbit (rad4jtch.yg5 3 z3e/ ixegius r) about a spherical planxy3ge4j 3cze. /5thi get (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and r.n2s yy sjslcc+6z/1 z2q9vzootates in the same orbit. Compare yncv l2zszys 1c q.sj2+zo9/6 the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compare t ssb 7ajf cmwl6-f;u e87;rmvrq3k n3 c2f-t,ahe reading on vns3mjf3bc2akf6 mw7t a -r;; 8s-rc 7fq,e luthe scale to the person's true weight.

  Who was the first person to realize thamo t nk0m y-*c44/epxgt the planets move in elliptical paths ar*k-4yoge0xm/ pt4 mcnound the Sun?

  The speed of Halley's Comet, while traveling 4 od0ku*r/xyk in its elliptical orbit around the S* rxkd/you4k0un,

  Let the average orbital radius of a planet be R. Let the orbital period be T. xh 3py+8ua3v2chbb y4 What quantity is constant fo3y xch+2pbuv3y8a 4hbr all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galf1c(zz br8) neaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that cfez)rz18n b(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 to2zp 6ynk9aw* +sc ;ayhe Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a yearz wyy;ca a+6s9np2ok*. What is the asteroid's average distance from the Sun?

State Kepler's laws.nn iu+;w9,o4eszj o,g

  List the four fundamental forcesf( lj wk*(s,qv in nature.

  An object moves with a constant speed of 30 m/s on a circular track of ra(q: n-yizb 4fxdius 150 m. -4nfby:iz x(q What is the acceleration of the object?

  The maximum speed around ahqlz3i5 g ux0 q1 )cazpnx27p* level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchaquix ga0c2 7)l35zp*x hpznq1nged.)

  What is the centripetal cxfk f l+l vt3.kpnw(8cc5js*8f3*v dacceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movincc j cdx*tsk f8(8w.fl k5f3+v v*3plng 8.0 m/s?

  A point on a wheel rotating at 5.00 regm+hm77 3b wemv/s is located 0.200 m from the axis. What is the centripetal acceleratio hb3g7e+m7mwm n?

  How many revolutions per minute must a circular, rotating space station 0e1b6g+,v pe1cd 9cvpvo k7h t q4p,ukof radius 1000 m rotate to produce an artificial gravit,qpc67+ep 9hv0v okt1e v41ckgpu , dby of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes a6.orup;1o snj+ 5 b pil.wjp;wround a 13.7 m radius turn at 96.5 km/h. What is the centripetal fo1julo. ppw jon b;iwr.5p6+s;rce on the motorcycle?

  A 0.50-kg mass is attached t /o9ybwwmea9q2b v ,4wpg5lj8o the end of a 1.0-m string. The system is whirled 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 theo2b48 g9 wwy/ ebljpwv qm,5a9 string is not to break?

  A stone, of mass m, is attached to a stronbr u4w4g4by1d hhk 3rcxy-b30g string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 timer rh3uy d4140whby 3k4x gbcb-s the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a st1 pj8wrwbvd ki-v rrd.38 g7/hol q9*irong string and whirled in a vertical circle of radius r. At the exact bottom of the pa j.w9qrb87/*d3 -ri wgr1ilvhdv k o8pth 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 acceleration of 4g wh*m y .tqs-l(epen pulling out of the dive. What is the radius of curvature of the loop in which tm (el y.q*pst-he plane is flying?

  A pilot makes an outside vertical loop (in which tr3tx/ j.tv 3xe d (1:eoht8;grvna(kuhe center of the loop is beneath h auvr :8 3gv3kee(/n(rxx;ht d.toj1tim) 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 going?

  The maximum force a xq0: qbo w(2d mo.x4 1*mnqdn7fscdh9pilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilqsw0 (qnm1:9 x2d.d*mfo7dn oh4cqb xot, 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 horizwsrwdu -6d xd;q2lh*ie6 9 a6r1su/d xontal curve with the tires on the verge of slipping. How fast can this car round a sec6i9eddu6l*1hdr x ud 2;q/ sawwxs- r6ond 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 curve of radius 50 m wxrwltmzb/ uiit2l+1v -.z)(sith a speed of 20 m/s. The centripetal force provided by frictibv1i-r2 ) +mt(izxtswl lu./zon is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius b5eg3e8 eus hj ,7r,an50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the turue3hsa, jeg8 e7b,r5 nn?

  A car is moving with a constant speed v around a levels3, s cd+g/bra curve. The coefficient of friction between the tires and ths bars+d cg3/,e road 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 bob1 vgui2mzl 1j,sled to negotiate a 100-m radius turn at 35 m/s without skiddingl1jg,mu2iv 1z? (Ignore friction.)

  A horizontal curve on a bobsled-dj 3 n-i-gt8r:eh.ujwgx0 sd run is banked 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, bankedlu(84twt m gmu,0ust5 at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ban)o a..hu-yox n l.1xdwvj qh7dw7 -j5nre:0wgked 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 ia6szl,b4+dy0rl g 5 min a horizontal circle, lr4 +bzy dam5isg0l6 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 acceleratet23pvxud18xq s at a uniform rate to a speed of 45 m8 p3q txx12vud/s in 15 s, moving on a 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 jqk 6)-ymg-86/ulf tvf 6vaxymass $1.67 \times 10^{-27} \; kg$ 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 per(mty 5xx9)s3bfq9 qz bson standing on the Earth, due to the Moon? fx)s35m bbz99tqxq(y 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 ste/ pwo59 4m4/ymr.pdji g6 nforce between two masses is F. If the masses are moved to half e tpnm 9rsgi6d4/.5/yw4opm jof their initial distance, what is the gravitational attractive force?

  For a spacecraft goi ,6e(0n6qoyz2b b.yzdf-hdcz ng from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the ocndqh0dy zb.6 -fe (z2z6y, bSun 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 61 x/ n of:mcnufp66rn$7.4 \times 10^{22} \; kg$ 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-walkj 2svqi7.ci4 4nn:rz k" at a distance above the Earth equal to th. jz7nicr44s:v2i nqke radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface wil3mw84hgqic)wg9h-- d nm;wxl l the acceleration of gravit;)xqh4 w lm9wg3dgw 8c--m nihy be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance5kc :23 -cjgs.h: phg klczl5i above its surface equal to 3 times the radius of Marsi5hszcg kcl 3c:kl p2-h.5g:j . 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 cent7ta7ap9h mg1wkgd+68 2w k6sq3v uxd eer, the acceleration of gravityh2xgq8kw sp a1vk eau g7wdm36d96t7+ 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 o1f x -jmva-*pb3xuj/n/ bpm 7kf the Earth. The Earth has radius r. If the object is raised to a height of 3pbbp-x/ a jkvu/mx-m7fj31 *n r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change okjzc5u w5+*ic4pmj6 when he goes from sea level to an altitude of 5000 kju 5*6jip4wm+zoc5 cm? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a poila+pu p2 /8 iz4ayya 5f2uxjt)nt 3r above the Earth's surface. What is the satellite's 8/ 5ai2 p)+ ytjuyu2apfzlax4weight?

  A spherically symmetric planet has four times the Earth's mass and t +fr9c2 y1tm .xpjk4ntwice its radius. If a jar of peanu2 9. pfty4 kctnxjr+1mt 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, Earthy z6 f*er,) 2m,(mwxbh:vwdhh, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass of bmy2w*v,weh d), h(fzrx m h6:$7.36 \times 10^{22} \; kg$; 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 trans:xt, xa. gl3*g +yivrcported 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 or3t(x +vjzt6iwbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radiuitx vz 6+3jtw(s of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about 8o jgy wqmy*gf)it(95m;o gx1 the Earth (i.e., it just skims the surface of theywgoq8f )mg*1j5tmxyg o ;( 9i Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 2;ndw ;g8m.uqd(; fzx p30 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Ea;(x8d .qmzug;w f;pndrth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, vq,53ik5)zzweqvurzux(v4; 8 bj m-p 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 ap b 2ckayq. hctq3(61lt45gxk radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a plan141hmv txpe4 qi-q,u ret in nearly 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 it tav hrqup 1tmq4,1ei -4xke moon B to complete an orbit?

  The planet Jupiter i pr:j.1y1)/ci ytfsp 4mu xh6khxml,x+4syi8 s $7.78 \times 10^{11} \; m$ 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. What is thl1k1hrpxh) t 9e average distance from Jupiter to the Sun? (The distance from the Earth to the Sun is tlx1hkhr)19p $1.5 \times 10^{11} \; m$.)