Is it possible for an 0mssd,eor y :gv0i .843 olkjlobject moving with a constant speed to accelerate? Explai8.l0 ,0 os:gmyej43kisro dvln.

  Consider a particle moving with constant speed such that 6+hv9.op ,+dxbv15r to yffaeits acceleration of constant magnitude is always perpenr+ .5ftf xd,+6vpoyhbv1a9eodicular to its velocity.

  An object moves in a circke7g;mnqqy* uw)3 r6mular path at a constant speed. Compare the direction of the object's velocity7uw)mr;q6g kn y mq3e* and acceleration vectors.

  When an object experiences uniform circular motion, ;;ms/zngu6; 2cz)bjszfd(l e the direction of the accele)bz nfdsz;zl/je csg (6;2mu;ration is

  Consider a particle moving with constant speed such that its accele jp1p2d3lo4ixvb 9,ni ration of constant magnitude is always perpendicular to itsb9dlxn1i vji4pp2 3o , velocity.

  What type of acceleratic4g/jg b7v4g( 2igagjon does an object moving with constant speed in a circular pa g2(g ggjg/cib7 4jav4th experience?

  What force is needed to make an obj,8of:rba1 u lazwne 79ect move in a circle?

  When an object experiences uniform circular motion, the direction4qhc 9x-whs6aw8 c fsy* 7:b4(nu lhrn of the net forl9h47b-uqfn4 hn: ss (8w6yhac w*rcxce is

  A roller coaster car is on a track tha*vlt2kxn i.7i8g lrk2 nnpl 69t 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 in22i*vgl 6nl9.r kxn8lit 7pkts centripetal acceleration at this point?

  A roller coaster car (mass = M) i +mxg q2( 0wqr(bt-ej1q 0viqts on a track that 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 theq 01qxi(qe0tbr-m tvg+2 j w(q minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circuzpjgpsoct1 eo7a/ x28m+;e3h m4xq z;lar arc until it is going straight up. Just as the plane is at its lowest point, the force pqcx ja13 oxm;/ogtz7 hp8z;e+e 2ms4 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 cwqffss*q;i4a78m9dtr go 3 dg.g-1x 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 it goes arc*c4,m q v-bdvwnfq96k( 4sii ound the same curve at half of the original speed. What is the centripeta4s-w k qv9qfvn64c iibd*(,cm l 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 spee2g5d4amsf ec o5 z ehf.qxnz7w2 e,),vniqp-:d v. Then it goes around a curve of radius 2r at speed 2v. What isgx,qfsn wz4 )po- 2,.7edzna v2me5e5:ifqch 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 xx1f 3j8s ;qqd rxt-.09uwlgobanked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negox 10qd9jtsxlq .w3grfo8-xu; tiate 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 k r*pb*rqb *o5st u58uf ,1hfgare banked at the same angle, but one has twice 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 speeru, ph5bb tu*rkf* q *o1s85fgd on the larger radius curve?

  The banking angle in a turn on the Olympi/3 (homcg4 cpkc bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team (/m4co h3c gpkwill intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to have both c 0)koi* m)cgqhvnav7 2fn2m z*entripemm) )nc2fnvk*aoz0qg7iv2 h* tal and tangential acceleration?

  The gravitational force b cr) x5 dv7mxnx/0+yp. jim)*( tfabbeetween two objects is proportional to

  The gravitational force between6 4slhefihl 73h2bqrii3i.o+ two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distancz1/b*zd 6ayv op ()3(ozgg *yfyl:eoue between their centers is cut in half, the gravitational forl*( yz/g) d*6fua1ozg3y :yobopz( evce

  Two objects, with massyrjpba6 oyfff(tzo ( g:j:e 0.81+clces $m_{1}$ 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 mass; be8kscwn;z +es $m_{1}$ 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 gravmyvh4z.bk9+w 4aj 3akg4q y 7titation.

  Compared to its mass on the Earth, the mass of anl qh-ak7 h2oi16r:pijo5,f tu object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earopt.2 +lbe .sxth. An objse2 .p.xot+ lbect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the/fc- av2 f a8mci;xb;l Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is/cg 7pks p vkv2 vfa,q-u:q3r( it beyond the pull of Earth's gravit-p7vv :u(, qqv gkc2k/arf3ps y?

  Suppose a satellite were orbiting fcb - -7gww*vomxp0g 3the Earth just above the surface. What is its centripewbx-m- 0*p cog3fvgw 7tal acceleration?

  A hypothetical planet has a mass of half that of thec:pt fyond+-2 Earth and a radius of twice that ofc t2:ypd +-nfo 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 is on Earth bymx, ,bg9h7s x7s oprz/y4w(. The radius of the Moon is one-fourth that of the Earth. x,mssz7oryg wp /4x(,y b7h9bWhat is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius ,kic k:bjp.8atj0k.v t+apk*of planet A. If planet A has mass m, what is the mass of planet Btvi, t kp+.pjkc aj80b*ak :k.?

  Two planets have the same surface gravity, but planet B has twice t- wss)2;8xrzwdazd ),ya+h5jxtnfp :he mass of planet+dt)f,as dzh8x5wpwaj rn-zy;) 2: x s A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite movinni wps,iiv31 k+iw(cd ws8.(vg in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellip inc3 wsii1iv.dkv ws+w,8((te's orbital velocity?

  Satellite A has twice * )j6oqbgjwa,the mass of satellite B, and rotates in the same orbit. Compare the two)* j6a w,jqgob satellite's speeds.

  A person is standing on a 5vefh ,f8o6+x;,1pg,thxtwr j:si ae scale in an elevator accelerating downward. Compare the reading on the scale to the person'+v; g1fw ,i5rs ep6eh8,xtafj t,: hxos true weight.

  Who was the first personoh3t x,gkt2 6uv+ka u- to realize that the planets move in elliptical paths arounvxuu -g 2o6h ,tkk+3tad the Sun?

  The speed of Halley's Comet, while traveling in its ellipmw c)gna)e16h tical orbit around the Sunnwhm) c1g6) ae,

  Let the average orbital radius of a o ok+m)+pr1ht0b 7 mv-qyn--ur+ hkd5f.ukms planet be R. Let the orbital period be T. What quantity is constant for all planets orbitingds-b kmrh +.m0) vktnuofuy+r - +k1ph-q7om5 the Sun?

  A planet is discovered to orbit around a star in the gaj. u zayrag jk e78x*/g:1kvhg (,-bdnlaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our k-jxgv1:.(8ekrd,7auzh ggbnj *y/a 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 defined as ocqxy :/+i fuxa k,mi 6h,*yv7mne "astronomical unit" (AU). An asteroid orbits the Sun:/hfau kc7 qym6vx+x*iiy,m , in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.n6d+8fu:e8:ya fuwdos h kk(sg 4:zn:

  List the four fundamental forces ilp/r)(c aupg v+k0q o fg/ys+/n nature.

  An object moves with a constant speed of 30 m/s on a circular track of radi;,1j2 5chj zyu gsh0fmus 150 m. What is the acceh5 suz0,jg;hy 1 jcfm2leration of the object?

  The maximum speed arb* yv-tdk,bbi. jw )*wz*snz8ound a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other fz. ) ,wby** ksb8 jwbiz*v-tndactors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle whdxk5kakb/; jz t0:e 9seel of diameter 70 cm when the bike is moving 8.0 m/9d e s0ta;/zbj5kkx:ks?

  A point on a wheel rotating at 5.00 rev/s 6 duwjmwr5v+l6oud 8/ is located 0.200 m from the axis. What is the centripet6jru5mwu/ dl6o8v+ dw al acceleration?

  How many revolutions per minute must a circular, rotating space stat(; (/ehzh 51mrsg3m/car b wmtion of radius 1000 m rotate to produce an a1wsr5m//(tmag r m3z(bh eh ;crtificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a3toj+: g7j k nvuy)a 4sx)q1iv 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcyckj yn3 :7v+svat o41 qgu)jxi)le?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The systeb g+)ul.uz xrtq. jx- u:ji*+z/ ;edsxm is whirled in a horizontal circular path. If the maximum tension that the string can withstand iu qsl;* +x:z jei+d t/g.xbu-.xjuzr)s 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is gtymwq n;j9hw w 5q n3u3:(t/ 3t.crrvattached to a strong string 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 stone's speed at thi:3(/n3 5nrvhrmcwwtuq9 yt3 ;w jg q.ts point is given by

  A stone, of mass m, is attached to a stro0d ag drs*6b4ung 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 thisg rsu0a6d*b4d point is given by

  A jet plane flying 600 m/s experience6;d*m.dw yz o5rvi8pk )w ch6is an acceleration of 4g when pulling out of the dive. What is the radius of curvature ofw68iyz; .crvwidmk )5 o h6pd* the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loc sr4yvh (jd71 x;d5idop 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 n 1c;ryiv 4djx7s(d5d hormal weight. How fast is he going?

  The maximum force a pilcnqy1ln3z; 8* hfmqs)ot 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 a1f yn)shzn;lm8*c q q3t a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve w/ oflkntpf4yvss2+-n +n4l+pv,7c gwith the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the snsvg+p2 -+,kcyv47os+ lpnfw tnf/l4ame coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve oi, kiuen/ * 6(qb axjcmlrq/;6f radius 50 m with a speed of 20 m/s. The centripetal force provided by friction crq * e,nxi l(bakuijm6;//6 qis $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cv j j q+4 xpe9-yohv1yz5y/t/furve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between th ex9jty+ p 4y5yfzvqj/h -v/1oe 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 coefficie u159xn aston;nt of friction between the tires and the road is 0.40. What is the minimuoa 1unxt 9n5s;m radius of the curve if the car is to stay on the road?

  What minimum bankingsy*opyx/y.4 * 5umr xz angle is required for an Olympic bobsled to negotiate a 100-m radius turn o z suy*45x /m*y.ryxpat 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsli,wz;ysvr* , i :-wadqjc32e yed 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, banked at an5m-t 3dh tt4pa angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80q-z4:qjs9 m mb m is banked 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 horizontal cirk h6 cdn 83eit()r pkhuu)4ab-cle of rad6b phk3eu8 )4 niadk(-tu)hrcius 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 uniform rate toz y 0z snc :*cd18qviar63u3ll a speed of 45 m/s rllnqz :i* c 6v81u zc03sday3in 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 protong/i 8pv)i: vhp(f(pm*kcpp2f 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 on a 70-kg person standing on the Eart:vavu,d01k,seen . ./if wr xth, due to the Moon? The mass of th :1unrf,at ./ xie.vds evk0,we 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 the3p,qhzg c/zr3w z)1cx 8ppz-tm3* ric masses are moved to half of their initial distance, wha*whpz/giz-mt3 z)8z1 c cprq3p, 3cxrt is the gravitational attractive force?

  For a spacecraft going from the Earth towardgp- jadirl 7-0 the Sun, at what distance from the Earth will the gravitational forces due to thelpd air-07j g- 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 ;)n1*f2zllnchw yp rcs7j:e:$7.4 \times 10^{22} \; kg$ 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 di/ f7jer8)os sxguo )+lstance above the Earth equal to the radius of the Ear)rso+lexs j8o u/gf 7)th. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will ta p ocis3.myxzb07n;i6ybw x 94.3 tfihe a7miy.;34b op ya 0z3xwxsb9cni tf .i6cceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal tgq2in g7 +uipk77w d-po 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, i7dg 7u-+pqn 7 p2igikws

  At a distance of 14000 km frrqum0k6 8t r/bom some planet's center, the acceleration of gravity i 0rmktu/q8br 6s $32 \; m/s^2$. 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 the Earth. The Earth has radius r.qjuevo, 96ui 24qdm)4 niof(a If the object is raised to aq ,ef( vuaj) 9umqn6 d4o4ioi2 height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg perff0uxp l d,))qson change when he goes from p),0xl) f udqfsea level to an altitude of 5000 m? (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 point 3r abd p- q:fmrw-(si1 6uvmove the Earth's surface. What is the- ifdp 61rm(vu-:qws m satellite's weight?

  A spherically symmetric planet has four times thexibd tc95t 1gz o))yk0 Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on bi1co0 ygkt x)9tdz) 5the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and 8 436ve ,phb (-dzzkamjone o3*o9 uqmSun all lie on the same line, with the Earth between the Mzpmj v6a 3ukem8d49bhoz*n3 q oeo(-,oon 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 pr;8mr7wt c8j is 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 civvmyv:rnf p8mg rg 4( pu 0zw,oesx(mq,,t/,6rcular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of t6 0zx :msmo, ,rv f8twe(n(/v,qp urmvp4yg,g he satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cir8ex5yaew4nq 0y 1:nddcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does yny8q0e4xd an w1d5:e 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 230 km above the surface of the Earthe(n7q ffd01- briph)zm +i zi;. It is observed to have a period of 89 min. What is the dph;)q+r7bfe-1n0iz zi(fmi mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital dia+u icqu x*rc 77y glhhht7* i1pt9-*wometer 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 0r(9q* 2fodsnmzyzr5 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 orbits. Moon A has orbital rad4, i8d)wc/qkxs*c bqdius 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 compw*sd4/id)c, 8q k xbqclete an orbit?

  The planet Jupiter is rar+kplj/1 y+$7.78 \times 10^{11} \; m$ 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 tob1 /6 jvk (v.j5cswxyp orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth jjxysbvp (k/wc6 v 51.to the Sun is $1.5 \times 10^{11} \; m$.)