Is it possible for an object moving with a constantvj:j9pi:)cd-q kewfp)bsa9 fl54o zw p4;a g: speed to accelerate? Explaigf9epv s: ; kpqwjci5dwl4 4-aap )jfb:zo):9n.

  Consider a particle moving with constant speed such that its acc-j7bt2;y8l )mz wru feeleration of constant magnitude is always perpendicular to7b;y8t eju f mw)l2-rz its velocity.

  An object moves in a circula+p4 ax w(v6dwur path at a constant speed. Compare the direction of the object' +(ax wpuv6d4ws velocity and acceleration vectors.

  When an object experiences uniform circular motion, the dii dex-9obgx+.7 cz7vbrection of the acceleration isx9de.vib+7 zb-cgo7x

  Consider a particle movir g t6/-d.qcw0dtzqy5ng with constant speed such that its acceleration of constant magnitude y0wg-qd6 tzq5./ctrd is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a s: do/+qjq 5u.zr*zotgzj69x circular path expergt+do:zqqxojrj*z z 9. /u 5s6ience?

  What force is needed to make an object movyoppy5/ ey elin03s m*+b 9/ave in a circle?

  When an object experiences unifor io)4o fmkq -bxz*+dk+m circular motion, the direction of the net force )fbz +mi*kqo- kx +o4dis

  A roller coaster car i6*rb +ob zqh2us on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its cebb6uz2orh+ *q ntripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track tha;unb;a7 f;l vnt forms a circular 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 minimum value for its svn;a;; n flbu7peed at that point?

  A pilot executes a vertical dive then follows a se(ab p ;ompfxq mh**8j*mi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on 8j m fhb**aompq;p*x( 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 rad/,);2biaq o xsbkrv5x crdc5/4x/ psgius $r$ 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 c70 w -labjnk23bvzo1tonstant speed v. Then it goes around the same curve at half of the original speed. What is the c 0obnjb21v7tw3kaz -lentripetal 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 7*wzaqui 20 (4vrapgqa constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car g 2qqvurwp07i*a z (a4as it goes around the second curve, compared to the first?

  A car of mass m goes aroundoi0 -tf:.wm q cn)v9jr a banked curve of radius r with speed v. If the road is frictionless due to ice, the-)rj w c .9fo0n:viqmt 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 arowno2 p) y6-* j f1heika67cnve banked at the same angle, but one has twicf-a2cv6npy)e6 h7io n kow1j* e 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 bobslo7ecojxr-f2)e sd5 x.ed track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "c 7)soerf.2e x5c-x djolimb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an tm+ 1a:eowak; object moving around a circular path to have both centripetal and tangential accelerateao:1wat+;km ion?

  The gravitational force between two objects is propo/q7 ewuhzpmvigm6hdm w/gw x)5 /8(0 jrtional to

  The gravitational force between gag+ t,+5 sxog9ivqx7dsn : qg*+cj+ itwo objects is inversely proportional to

  Two objects attract eacho6eosw5 s)x6mz2( xmmzh:k)n: oi34 r m, fmxg other gravitationally. If the distance between their cenix)z w:r(geo6s)mmmh mn ,34:6kz2xx 5oosfmters is cut in half, the gravitational force

  Two objects, with maslscar5pf ,nh: a*6yd/u0t.bu9 qg.z oses $m_{1}$ 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 massess)(3zui el 8k k)amx(e $m_{1}$ 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.fkbz,::)mw7m.p rh k p

  Compared to its mass on the Earth, the mass of an j*f mk0j );caw6 gnjrfxgl(: 0object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An* j/70,oiepb*yzcxef objecxfi0*je eybo7z ,c*p /t of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from thenua+h bg 35v.hcfwg:7 abl5j 6 Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what pointo2ww cosictl /8soom/38sn( , is it beyond the pull of Earth's gmcs, sn8o3w8 o/o2o w(itls c/ravity?

  Suppose a satellite were orkgk n ;49v5;hkjgoyuc)z4 o9obiting the Earth just above the surface. What is its centripetal agyjokz;u9 k95k44g) hn ;ov cocceleration?

  A hypothetical plane r*pf8e9lp5v /li mj2lt has a mass of half that of the Earth and a radius of twice that of the Earth. What is l8r5f vl2p9 lmije/p* 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-sixtx zpvd) 9-3cgnh what it is on Earth. The radius of the Moon is one-fourth v9nx)-pgcd3z 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;6.d,1w l ivesc1 cdzn has twice the radius of planet A. If planet A has mass m, what is the mass ofs1 .1eclicz wv6,; dnd planet B?

  Two planets have the same s uy6oi7l4ikb f7dioza9t0ey1 n6s:8uurface gravity, but planet B has twice the mass of planet A. If plan0b tz7 yluu o:i idkio 9a6e47sn16yf8et A has radius r, what is the radius of planet B?

  Consider a small satellite movi)8c/zttpqnq * ng in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellitt)znp/* t8 qcqe's orbital velocity?

  Satellite A has twice the mass of satellite B, and rota vuva9,w: m2:bj9 gnorf.l+nttes in the same orbit. Compare the two sat9jbu:tn lwg,:ovfnvm9a2 +r. ellite's speeds.

  A person is standing on a scale in an elevator accelerating downwarg;8u v3 rfsdy5d. Compare the reading on therg5 u f3;yv8ds scale to the person's true weight.

  Who was the first persos .r oj;9:hoqcsvn kqh m 8+p-ph5:zo/n to realize that the planets move in elliptical paths aro /;.m8qn osrvq pcoh+9 js:z:h-pko5 hund the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around thexd *g7( atvpa;s8ef(g ea( 8adfts(g 7xg*; vpSun,

  Let the average orbital radius of a planet be R. Let the orbital 0mq8nynga9tt 38g+iqperiod be T. What quantity is constant for all qtg0q8m n9ty 8g3+nai planets orbiting the Sun?

  A planet is discovered to orbf 9var n/te2w5it around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of 95vrwa 2tefn/our Sun, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance f iw42zwp8q3:- a4tr apfw1+)bsux xk ha lta9-rom the Earth to the Sun is defined as one "astronomical unqa:s+)p- i wtwz4 -ah41p9bkxaat ux3 w2f8rlit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.*2hejn: 4z bdr

  List the four fundam79ct*0ha ;( od*y qqy+8 mu aphadtw9mq3hl5i ental forces in nature.

  An object moves with a constant *d 5*wrxd9lnl speed of 30 m/s on a circular track of radius 150 m. Wh l wd*l9*rd5nxat is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. d8,-0fwhdwi2i etf5k What is the maximum speed around a curve with twice the radius? (Assume all other factori2wd8f,h kitw0-ed 5 fs remain unchanged.)

  What is the centripetal acceleration ;cjv /5f; a69sqh-dp2x riv *hy rm;qiof a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.ir;y* ;mf65dhh/vcp2qx 9i-s rq a;vj0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. Wc3u u(0m+fq .wtekqn7hatf qmqek.(3 7u0+u tcnw is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating 9nl8 h p4g wgt/ft)pl(space station of radius 1lggpl (n/4wt8) hpf9 t000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It h6yx4nwh 8x ejxk7 *w+goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motow*4+x xhhyjk86ne7 wxrcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirled .y.wobphn,4+,xtfs v in ,,f.bo w4vpns y+xt.ha 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 to break?

  A stone, of mass m, is attached to a strong strin.m*xhf j3l b(wg and whirled in a vertical circle of radius r. At the exact top of the path the tension h(fbw x3.lm*jin 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 strn*v- 2uurk c1dong string and whirled in a vertical circle of radius r. At the exact brv 1uk2ud-nc *ottom 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 acceleration of 4g when pulling out ofs nw-lqz+t+c. the dive. What+tls w.+nqz-c is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside verticaldz5iyre 4s7 (o loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he i y(7izs5re4d os pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his wei sw+cih +s (w2qpjt-t nt1;1gcght. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a++stjs w 1g;12tw(hp cqtcn-i 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 the tires on e/24ne5o71vcy cr(sg o,uo gqthe verge of slipping. How fast can this cay5v7uq1g42c( o eo/or,g csne r round a second 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 with a speed of 20 739 z g(ko/p(smk asmhm/s. The centripetal f /(spk (g7ko9samhmz3 orce provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flajz-nlz ( j5x7mt curve of radius 50 m at a speed of 14 m/s. What must be z-xz5j(m l n7jthe minimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with :f -ertid+:*bnup 5:f2ykvh ya constant speed v around a level curve. The coefficient 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 oe :vrynt k :uiy+2f:pb-dhf* 5n the road?

  What minimum banking angle 02 aw.jxckp-eis required for an Olympic bobsled to negotiate a 100-m radius turn ax-0 je wcp2.kat 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on -1e8 bnhanv7ua bobsled 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 radi(+(fydth+ 0h o(preq 2r8fvocus 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:)a lpmd/-pl 3 naac(v $45^{\circ}$. 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 iwx y9de,wks1.w (s8cos revolving uniformly in a horizontal circle9wdxwceys18k, o(w s. 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 at a unif5 2cc24 szt) ptw1wwidorm rate to a speed of 45 m/s in 15 s, moving on a circular tra2 c w4s5zttiw1d2w )pcck 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 proton7n( gc); rgywu 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 forxif5igsl u +o4* p,9qyce on a 70-kg person standing on the Earth, due to the Moon? The mass of the M *9 ig+ 4oxiy,5lpuqsfoon 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 thjm:dz rk q*sgar.g f)+z3n3gwm w( .;he masses are moved to half of their initial distance, what is the gravitational attr+jw;g )q w3sd*m a:3mzh(rgrz. g .kfnactive force?

  For a spacecraft going fromqx t-evz4r;cb0 bao60 the Earth toward the Sun, at what distance from the Earth will th-zq 0a;otcerb06b x4ve gravitational 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 xkqv5j r0h4 6qis $7.4 \times 10^{22} \; kg$ 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 Earth eq: mi egk6o fz,))gsh:oual to the radius of the Eart6i: zof)gheom)kgs ,:h. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distaobla *i0*x -gof 0z+t o+llpq5nce above the Earth's surface will the acfl-+a*+ il*ootp0gzl50 x b qoceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 timqi-5rg1umase9g(s v 1es the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars5vs1gmu9-1( a erqi gs, is

  At a distance of 14000 km from some planet's center, the acceleratiez ( h;mlmo)ymc)p.x 8on of gravity eo)(z;x)pm8ly cm mh.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 sq9 i 7ipa.8trgurface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's9pqit87 .igar surface, what is its weight?

  By how many newtons doesmb x -9k098g-m wizix/z+ ojze the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean rad9ek/ mgxi8 mo-w+9zjib0xz z-ius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r4p3 tp/dv (g.0 o8aghb ype;bw above the Earth's suhbta /egp.(;o8dpg4 vy b 3wp0rface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice 7: rigqejjfp 8o4 h(ccb/d*cdb13sz )its radius. If a jar of peanut butter weighs */1dj7)(g c48fpdjch 3bz ceb r io:sq12 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 allzitplli6 l; ,w 3ff6s5 lie on the same line, with the Earthpisi6 ;53fllf6ztw l, between the Moon and the Sun. 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 the / /kszc1e, ml5dmvl) fMoon.
(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 Ear )lw+sul flm.k7s, g, xw-gmx4th (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Eartxmsx. ,)l-kgwmgull4 s +w,7 fh is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about ,.)w lrd.mp0y .s.wmgeeczv*the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? ..pye.,wc.zdms0l *) mev gwr(The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surmqj2frh:7i:a p3q q 8nface of the Earth. It is obser7hq:rn 2 ipm a3:8jqfqved to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an ocr dqtk)4f93brbital 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 a radius3c xtxy )cq87hugf;2 ch6rxk, 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 nea. vw()yyq1v5d3tf8il*l o y krf5 uhd*rly circular orbits. Moon A has orbital radius r, and moon B has orbitf8 fyr**ot) 3l1 . v(5dwiylhqy5 vkudal 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 isz5 m 8/;7edgia p,tpgy,sd x;g $7.78 \times 10^{11} \; m$ 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 +z l 2+:*cupbyqc3sk n12 years to orbit the Sun once. What is the average distance from Jupit u2cn:yp*3qs cl z++bker to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)