Is it possible for an object moving with a constant speed to a.qo vhnwax+1uc +4o,z5 du5)dzra v k6y hg,i8ccelerate? Explai oxkz,)rd16 n+h.ayi8a4oq5vw + zu dg 5hcuv,n.

  Consider a particle moving with constant speed such that its acceleration of c2*a mhtn v14bzou 9+cionstant magnitude is always perh9n21zi o ub+c*vm4atpendicular to its velocity.

  An object moves in a circular path at a constant 5*evc.kr0 kb *ay5i pkspeed. Compare the direction of the object's velocityc. *0ekb5kirpa5 k y*v and acceleration vectors.

  When an object experiences unx2-z ; c:silkciform circular motion, the direction of the acceleration il2 -cksz:c;xi s

  Consider a particle moving with constant spet )8w((,vqsr yntth gr2/vs z8r 8w-qyed such that its acceleration of constant magnitude is always perpendicular to itn8rth) rvw8 r-w/sv tzqst 8y2,(qg (ys velocity.

  What type of acceleration doqkpwpskl /qflq/2w b688;e 7 oes an object moving with constant speed in a circular path experienc fpoq7 2el k8b8 /p6/swqwq;kle?

  What force is needed to make an object m):bi uxvka nf32 n9*ouove in a circle?

  When an object experiences uniform circular motionw-d0b/ p *pn55i wm54 fniadnt, the direction of the net force isp a4imwn5-p5n*w5n/0tfd ibd

  A roller coaster car is on a track that forms a circular loop in the vertic:z0omv qtz awsn1n76.al plane. 0oztv n7a:m 6.1qsnz w If the car is to just maintain contact with track 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 o(hs-z 4.ezms r6v/wlc.cvmfe pg 737a 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 the minimwrf c4mv moh c. lpg (6se-/e.z37sv7zum value for its speed at that point?

  A pilot executes a vertical diu ei( m:eej seq*kl4o(( 7g hum2hqm)8ve then follows a semi-circular arc until it is goilhsee 2* mkhg: m8u(ui((7 ee4m qqo)jng straight 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 of ra5i 5t mnd9dqg 7nmnyb4e5g;d7dius $r$ 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 speef0ops4vo 0pid ae: mqj2 8/cx2d v. Then it goes around the 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 ti/ 0c0d8 :j4paoxvoiqsfm2p e2me, compared to the first time?

  A car goes around a curve of ra b fb7yn1(qrnj2 */m+stk(eb:0za fsadius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v.r1qfemsk /0bnb yz( s:7(n2a+jfb *at What is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes aropur d 0i f8rwvs2/x(a,uh7od-2h *szqund a banked 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 ru,-2wds qrh7 /i2ou(rf zdv80*h psaxoad is equal in magnitude to

  Two horizontal curves on a bobsled r j;(3q+k-l6 b2bt,rsty d+jrr eu+zyb un are 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. Whaezj 6,y2t +b-burlr( q3k;byj+r sd+tt is the safe speed on the larger radius curve?

  The banking angle in t anfg ;/c;3xva turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower c3tn/gca;f x;v oming out of the turn. Why do they do this?

  Is it possible for an object movivggl:u6/9sytto.q+3b/ umlb ng around a circular path to have both centripetalqvu6u+. 3lb/: my9g/ sbotg lt and tangential acceleration?

  The gravitational force between two objects is /0hk er/dxvl(d h+6f hptdsxy.:g0r) proportional to

  The gravitational force between two objects is inversely pr7 nu)wmq21yoo 0h4.mq 7rlb8dgixyl (oportional to

  Two objects attract each other gravitationunb iad8j.llmdu ;1.;ally. If the distance between their centers is cut in half, the gravitational lmdn ;8ab.ij .d1l; uuforce

  Two objects, with ma9/ig5 ck3wsxseze .,qb.v2k f sses $m_{1}$ 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 masse* x;bs n8-6wu7p8a pcg *kdnpfs $m_{1}$ 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 graviot, )d9yf0 ik+npsayl o j*3j/tation.

  Compared to its mass on the Earth, the mass of an object on the s pe/tg nq)eo3 .ti)(lMoon is

  The acceleration of gravity on the Moon is one-sixth what itapw beq, v,(2i is on Earth. An object vwb2ai ,(q,pe of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's i-.l;xeqhrvtp z+4*q surface, the rocket's weight

  A spaceship is travelingub w+jdblp c1naw4a g.8 ,lu7* to the Moon. At what point is it beyond the pull of Earth's gravj+w 4w*n aul1a,g uc.l bb8p7dity?

  Suppose a satellite were orz nkfbio .5ynf,v7 g8;biting the Earth just above the surface. What is its centripetal an8b7;gi n zy.f5v f,kocceleration?

  A hypothetical planet has a mass of haco:8lrxjw9.ynvf p *4lf that of the Earth and a radius of twice that of the Earth. What is the acceleratw.r*9ljcxvn4o p 8:yfion 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 itvbqybtxhhraqde )5ec7 / , )3i.8rn*s is on Earth. The radius of the Moh*ca 5qxhit3q by7)dr, e srev).8n/bon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravir i9xts-i(csu u 2n;1tty, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass i( xu t 1u2rs-ni9sc;tof planet B?

  Two planets have the same suxr5up m2)j03pdmf wt4rface gravity, but planet B has twice the mass of planet A. If planet A has radm4dt)pu w 50px2j3rmfius r, what is the radius of planet B?

  Consider a small satellite moving in a c1q9 g/yg r*jgm --gvp eh:i5lh5 g,opuircular orbit (radius r) about a spherical planet (m5o1- 9j:ggu gp-,rqephy5l/*hg mi v gass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and r. cu5tghp8reyt7:j+ votates in the same orbit. Compare the two satell7 h5.rug e :t8vpctjy+ite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Comparexulu *+hw2g v+ the reading on the scale to thu+g wlu 2xh*+ve person's true weight.

  Who was the first person to realize that the planq t:0*3dnmoz yjdu)r)ets move in elliptical paths arou0dnqtuj)o3m: y) *rzdnd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit arouo3,sqqwhi5z8 o;3/jtkc y4 zxnd the x35oqh,zwk j8iozs4qt; y3/ c Sun,

  Let the average orbital radius of a planet be R. 5 2zws mo-j7 +w1qovcu Let the orbital period be T. What quantity zw o 7juc-+25m1 wosqvis constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a sc qm9ejoth 7+7tar in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun7e7jhmo qct+9, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth k)7h een263ex:m x xrc/cw m:ato the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteh3:xc ke6m) mxa7:e c2/w nxreroid's average distance from the Sun?

State Kepler's laws.c /x;8 x)ytymu

  List the four fundamental forces ijylc4v v(mos1 pe) ,**aj/xexn nature.

  An object moves with a constant speed of 30 m/s on a ciry :6hgwuz*r 1vcular track of radius 150 m. What :uz6 1gy* wrvhis the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum zu4puj9jl xvp/b+fe8-j ks xl9e 0.s9speed around a curve with twice -kpjlj9/.ex8v0e 9sj+ pf4 lz x 9bsuuthe radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter00 aggu hpbk//eaz( hxx9c6l 6 of a bicycle wh( 6zak0 phaexxc6/lguh 0b/g9eel of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m fr20hmysp 5a;a8fq pb /x+o7lj9sbos-tom the axis. What is the centripetal accelera89japslqbo s;7-sb2/0m+ o 5hxftypation?

  How many revolutions per minute must +c, -tbe0vq5aj yw4ep a circular, rotating space station of radius 1000 m rotate t0q4 jeetv b+ap -w,y5co produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turxhvr )l;p8 1h ju+mi5a,pmqd1n at 96.5 km/h. What is the jpdv5h1mpm;,a ix1 r)ulqh8+centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.;k9gftv5vr nce6v 6 q-0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. v5;gr- q 6 cnvtevf6k9What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a;1jb1r 0y hiec vertical circle of radius r. At the exact top of the path the tension in the s1 jiybhe;rc 01tring 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 an vz.vxe3qhpf0*g x 8dtu9;+*5n tlmih d whirled in a vertical circle of 5+pe*mh. 9d0vlvtixf *z nq;g3 hxt u8radius 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 this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4 cy.z,x6ig)d 3 y0epfzg when pulling out of the dive. What is the radius of curvature of the loop in which the pxe igp6z)d03zy. cf ,ylane is flying?

  A pilot makes an outside vertical loop (1is86 qo; 5liw:myz rfin 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 w 1 rm w;zio:qli5yf8s6ith only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand4qc*s l 2s /l1sk fg;rdp.x yu*b8yr-h is about seven times his weight. What is the minimumyrf**.28x bllyq k1s-ps; gs/h cru4d 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-m radius horizontal curve withmpn23tcdvf4k, 6 tsa goi4+d 9 the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same co3,s cvtg2akmdo4in46df tp+9 efficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m wip: nnfom;y h;9zk -,0-g lm.eq7eqwzs2mkw3jth a speed of 20 m/s. The cenh.j ;3 mz0kemw9o w,;pk e2lnyzm7sn- qq-:fgtripetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a speed of 14 m/s. What0yg/j( b+t hovob*a- g must be the minimum coefficient of friction between the tires and the ho *-o0yg(vb j t/g+baroad for the car to make the turn?

  A car is moving with a constant speed js: :x ()bkko aziw n/)adkj28v around a level curve. The coefficient of friction bes/:2k8zi: a)n(jd) bxwk okajtween the tires and the 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 bobsled to ne kl8 owxj7p7yw8e: dl*gotiate a 100-m radius t8wy8p:e 7kd jlxowl7*urn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankeduu4d10hh q,sz 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 wx*/jba-s b*k;;ru qgradius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedq.j;+ kw(jlsn 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 strirew(av47z y.-ay9u6fl pc 5j2x p,qirng is revolving uniformly in a horizontal circle of radius 0.ru6ra(pl,yyw-7 vc zax2iej5q p .9f4500
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 atb(jst i2,6xit9qa * dq a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill qq j*isa9tid x b(t6,2in 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 protut ;puwnnce8*o wbi:e y/ z9*i2,rwo 4on 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 o5dy ,z( dtcve5n a 70-kg person standing on the Earth, due to the Moon? The mass of the ,vz etcdd5(5 yMoon 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 the masses ared 3vc,y )qi/. w)tnjkk moved to half of their initial distance, what is the gravitational attractive)djtn3c.kv) q wky/,i force?

  For a spacecraft going from the Earth toward the Sun, at what distance from tx mu- cb5qg:f;kr/4 nehe Earth will the g-x;m uceg5qkn4:bfr/ravitational 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 i fh;v ,y; )xsyremnz*;s $7.4 \times 10^{22} \; kg$ 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 Eandi rti. z(,tplqb h1e/k(16x rth equal to the radius e. i1tpzqbd6tlkxrh, /((1in of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above tm+cfl2e3w 7t( q0vdsohe Earth's surface will the acceleration of gravity be (flto+w20d7 m 3csqev$4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equgs cy -eb o4sa+(qf1uyi2v8hpt;k)lr6vg / (eal to 3 times the radius of Mars. The acceleration of gravitysh8ve) r-u ggs/ve(yco+p4lt ka 16qy2 bi(f; 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 acceler9 or: ns9(a4q7 shfkskation of gravity q: 9h fk(nsos 7k9ar4sis $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surfapb0-cyftnt3ll /4+ nr ce of the Earth. The Earth has radius r. If the object is raised to a height of 3+n0bttc rf3 l-pl y/4nr above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person u7cjlia hs,j u/70p tm2 gnz4(change when he goes from sea level to an altitude of 5000 m? (The m0atj uslh/2zu4ncg( 7j7pim,ean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satdi* bbs*1g nor+ky. +mellite of mass 100 kg is at a point 3r above the Earth's sun yk *b+g+1.dbs*m oirrface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its ra ecy+bfno4 ra63fu) a0dius. If a jar of pean6auf3fbne 0 cr4y+a) out 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, wi) fekp,0 ,ienu7bxxn*th t*eiufnpk ) ,e0x n7,xbhe Earth 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 tr6bbtfj,e6a9m4v p w(lz )4 vbtansported 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 mpwt 7z )cut*/low circular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean r)w*zt7t/ mpuc adius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth.76d myv2lec(da 3xe r8co o1h (i.e., it just skims the surface of v7(dc136.o xhyrlamoe2c de 8the 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 oa4lmv3+i n-(b8 h fyvarbit 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 radia fi-h 4v83b ylamv+n(us of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupibfg95 kljd()p o /;vphgi9i w7ter, 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 ,nifb 9p cdhx) n36kb)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 or/7r 7d oe t+o)9kzyy*hkb;gryl ,yp;nbits. 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 Bbky7y,g7rdn z yr p9lht e;ok/+oy;*) to complete an orbit?

  The planet Jupiter is 2.u- ap:s svm,,mlabo$7.78 \times 10^{11} \; m$ 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 the averagaxi z/j3f ainv)t: u iqh1 alrq/xm,c3r3(5l: e distance from Jupiter to the Sun? (The distanc/mhu 1 r)xz3(jv:a tirqa,xc33llini/q 5:af e from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)