Is it possible for an object moving with a constant speed to accelerate? E3pp)r0-kpmf f xplain0)pp-rf3pfmk .

  Consider a particle moving with cool.76yk /k q 8tii-oxlnstant speed such that its acceleration of constant itl8kk qx i. 6o7y/o-lmagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dik ja5+/gs:c1dzg pdk5rection of tg :adk5zkjcsd+15/ gphe object's velocity and acceleration vectors.

  When an object experiences un ij5v)c7h2ibh uw) xe4ib+:jgiform circular motion, the direction of the acceleration 2wbib c:4j+7)ghh)5x vueijiis

  Consider a particle moving with constant speed su2515xk9c ,fzwr scmbp ch that its acceleration of constant magnitude is always perpendicular 9z 55mpcwfr1k c x2sb,to its velocity.

  What type of acceleration does an object moving with constant spe8zx(8/g49jplf 0u avec : srxked in a circular path expe ve :jc8lxfur8/azk 9g4(xsp 0rience?

  What force is needed to make an object mov3,bvc( 1qwvz ue in a circle?

  When an object experiences uniform circular mo;bm8 3fou7 w6bfjy3 tztion, the direction of the net force i67mzw3t8j3uyofb; f bs

  A roller coaster carl- .aboz o3:c7l1fuyq is 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 fobaz3l7 o lcouy.1q-f:r its centripetal acceleration at this point?

  A roller coaster car (massn zbi yy i:5r a::lfr5-eyl;-z = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just mai: :n yeifz55liby- :-l rar;zyntain contact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it i :*12yckry-b yzms 6mns going straight up. Just ak b cry1 6:*-sy2zmynms 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 radiuf, ht+ay lm)6v6tglmz;v4 x r7l;wr*ks $r$ 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 cone1 5bz/qf8m brz jr h2gml8e+en2(vw 7 (3nweestant speed 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 time, cebz 2lhn ( 881 w2mbz3 mne/ rege+7jv5fqrw(eompared to the first time?

  A car goes around a curve of radius r at a constant speed v. zj*ie b+t/ /48xwhzvq0umts 1Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as zuse8/z*0h jiw1tx4vbm +t/q it goes around the second curve, compared to the first?

  A car of mass m goes around a banked c,b2,8 ysai cidurve of radius r with speed v. If the road i8 , iy2ic,adsbs 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 magnitude to

  Two horizontal curves on a bobsled run are bankeco+cm e1cwqr i6:tr44d 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 th6ro 4c 1crim4w+q ct:ee smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympx.m vq6 o,lq7eic 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 coming out of the turn. Why do they do tho. qmql, 7v6xeis?

  Is it possible for an object moving around a circular path to have both ceic3d 66.ml0xs7yjtp y:35jglzr8 fewdl )4 ubntripetal and tangential acceleration?7slpt6d ) mje8x:br6 jy.4c0i 5gdyfl3zw3l u

  The gravitational force between two objecjvr4l)4aw9 h 4yg ez8gz ,w4vfkn(c.ets is proportional to

  The gravitational force between two objects is inversely propes;-gsyy lc r(76 i(jnortional to

  Two objects attract each other(9y dwozcr 1/jin1.db gravitationally. If the distance between their centers is cut in half, the gravitay d1jd9 ow.br(1zi /nctional force

  Two objects, with mas)rmdfgoqg y1owe/:/3ses $m_{1}$ 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 masjbe w k;k2b;0yses $m_{1}$ 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 gravitati-/sxiejb9x1 3vwtt2 d8sb31 ++ujvt 0 rxze tgon.

  Compared to its mass on the Earth, the mass of ann-) ioqr6jn r302mgia object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An obh;-t3zs;sq4z ;un venject s;n;te4nz; hu -3zsvq of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earhipr lw1i2-b8l- g* viu 5on.ath's surface, the rocket's weight

  A spaceship is traveling gxt9doa.v2oa+5 noduqn8 f ++to the Moon. At what point is it beyond the pull of Earth's gravit8oa qdo+ ftn92gvn udox5+a.+y?

  Suppose a satellite were orbiting the Earth just above the surface. Whfzpeq -c;chu34y,cy; w 3rkk4at is its cent;-h3;crq p4yc y wfk43kc ,uzeripetal acceleration?

  A hypothetical planet has a mass of half that of tv. yxb4 7,wfnwhe Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the accelerati,.vwnbyx47fw on due to gravity at the Earth?

  The acceleration of gr 8a:abym n7/:4nazt xzavity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-n/:xa:amz7z4bn8 aty fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gr 0iddhgv2 vb05avity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planet B?vh002gbd v d5i

  Two planets have the t -h a fop*ryfb9sio8:.g +3gusame surface gravity, but planet B has twice the mass of planet A. If plane-gsi o+bpfhoy* 9utg fr a8.3:t A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbiy w4hwh1g ;y +8cz+ogjt (radius r) about a spherical planet cy yggohj;+ 1w8z4h+w(mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. e) n/4auexm 8-gsbz7b Compare the two satz bsg8a um)4- exen/7bellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Com n073p:f if9qszlqjk6 pare the re i 6kp:7lqszq0n3 9fjfading on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical wz:)hw s5zt8 spaths ars) s8hz5tw:wz ound the Sun?

  The speed of Halley's Comet, while traveling in its ekflt: 9jk*zu d/f6 cy-lliptical orbit around the Suuy*cz/tk9-kf d6l: jf n,

  Let the average orbital radius of a planet be Rt.a itt61cu2g . Let the orbital period be T. What quantity is constantg .ttta6u21ci for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Androy.;h ;go- viqdmeda, with the same orbital diameter as the Earth around our Sun. If t -hqd;i o.gyv;hat 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. oabumq0v+u9 the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one +m9qauo0 .ubv-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.sdz:z(cx-3 q l

  List the four fundamental fo 8q pqopv/1 daf6 6m,o2spub0trces in nature.

  An object moves with a constant speed of 30 m/s on a circf.jpk * 7cv8 uhtg6f:bular track of radius 150 m. What is thpff jvk7*.g c tu:6hb8e acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the mag+4kin tup+7*p*a+w9 o txyg4xesv9w ximum speed around a curve with twice the radius? (Assume all other factors ++ o tpikn+9wgu*tgxe*py x 9 7sav4w4remain unchanged.)

  What is the centripetal accelerationjwj(w)nmz-s 0cfuoou mi2*)t1q c i26 of a point on the perimeter of a bicycle wheel ofj6(i zc f)2utj c2onsmq)-m0u *woiw1 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 from the rb23ak-k a1j 2smat:eaxis. What is thesmbk32ae2 :aa-k1jrt centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of rae7fffx1,b( w ndius 1000 m rotate tonw7 e bffxf,1( 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 turn 3q7jg/16xg( pa dp 9ig*nxbsm at 96.5 km/h. What is the centripetal fo3/*p(6gdbqgixampj71 gn9s xrce on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system0filp,3cz l2t is whirled in a horizontal circular path. If the maximum tension that th2li3t c0lz p,fe 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 as vs5ifxd9 )qqqfg7)me.; +mr strong string and whirled in a vertical circle of radius r. At the exaqqg5dm)+ q;fr e79sf mvs ).ixct top 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 stone, of mass m, is attached to a strong string and whirled in 3b38kn h hiyt+2xlur6 a vertical circle of radius r. At the exak2i 8yuhlb3r t+6x 3nhct 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 4g when pullin k;-etj4fj q*ig out of the dive. What is the radius of kie * qft-j;4jcurvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loorgdca*dvxz 6oe7p- /7zbou *(p (in 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 with only one-half of his normal weight. How fast is he d6vurcd/zo(g7ab e ozp*7*-x going?

  The maximum force a pilot can stand is about seven times hil) xfyx*zg4 : pqdgtq 8jjjv7jy w20kyxy,)6- s weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a spy,j q-gy60qxxtp xv8k)dj2:fj 4yz*)y l7 j wgeed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tz5d n 0rgt94lrires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficiez40l5 tnd9 rgrnt of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of t2o)i:fz umaa 16fnl2 radius 50 m with a speed of 20 m/s. The centripetal force pr2fto:faa6u n 1 l2zim)ovided 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. What must b5aq kyyb dmku8jt+ r8*o-3k 0te the minimum coefficient of friction between the tu 8tb0+kk mo3y5j qr-d*ak 8tyires and the road for the car to make the turn?

  A car is moving with a constantp o)r8qrf.l iy (u05uh3:vr rn 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 rri 0(:l)85nrqvyhou pru 3. fcurve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 1 s)2 q;flg-0-uhb znaqpa0w;z00-m radius turn at 35 m/s without-fz-bh0lua nz;q p0wa;2s g )q skidding? (Ignore friction.)

  A horizontal curve on a bobsled ri5)* axhv05sz wuf h:;eu7ul+ ppu8 qyun 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 r 84h1/*ardaco* yb; 9 nlwgpzcadius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 1te 94lt i3hj(qpb /b 4yfm/azm 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 ak 5px .coz a8 7c94qo1muwg,hd horizontal circle of radiu,p5zdmcoc 7x1 wug8qo94h a.ks 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 t*cs1 jt10i,lg-q j xpdo a spe, 0qdjlxc* 1jpigst1-ed of 45 m/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 cok 67wgp5;/ck pvnafd /nsists of a proton 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 standinq6dlmbaa 8k ha10 2.hxg on the Earth, due to the Moon? The mass of the Moon is a02hl6 1qdbxaa mh 8.k$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive forcedjstlmb r1:kt ):b-j4b-yj 7 l between two masses is F. If the masses are m)7j js4ll:krdb1mbtb t:y -- joved to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun,-qka,v8pi* 8z*rdaxa at what distance from the Earth will the gravitat,ava*r iaq pd*8xk-z8 ional 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 hq9/apqzl t1f6: kc p )*lonj:m ot/wr8lh6:g$7.4 \times 10^{22} \; kg$ 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,+v7w/ vid fpv above the Earth equal to the radius of the Earth. What is her acceleration w/idvpvf7,+v due to gravity?

  The radius of the Earth is(q sme0vzr-qbir/e 6avdv, )+ R. At what distance above the Earth's surface will the acs+e0(z iqrva6) qre,v dv-m/b celeration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its su cx;gk 503ji q.au;inhbn +mw5rface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of xgiq +5cbmi 0 .u;;wk 5nah3jnMars, is

  At a distance of 1401ug .xzfg*8ssca yx,6 00 km from some planet's center, the acceleration of gravity 8y.sa 1*f uxcx6gzgs,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 of the Earth. The Earth s3+ kl 5 7ovf4t9u2vsz,cdb; xjqpiz .has radius r. If the object is raised to a height of 3r above the Earth's surfa9sk s7lf 2xz+ .;bc3v ,qtzo vujip4d5ce, what is its weight?

  By how many newtons does the weight of aedc-q+5 q(i(4jqavk n 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of theqqec4+d ajn ( qi5(-vk Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r abovar c- kqc wf/.y569du2wxnid2e the Earth's surface. What is the satellit qaf2c5k ur/ycndd w 2i6x-.9we's weight?

  A spherically symmetric plvsdaf3 h:u d4y4j,z+zzwb)* wfzxos * eye;:6 anet has four times the Earth's mass and twice its radius. If a jar of peanu wzz4*:+jy:e6zv3zh x ueao*;4sb ffwdd,) s yt 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 liezask(3fp r (t0 on the same line, with the Earth between the Moon and the Sun. Ther fpz3k(0s (at 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 Mosethabqt.qt4.vg 4n*yqa * 55on.
(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 982rzd fzl8 7eawmeb,low circular orbit about the Earth (i.e., it just skims the surface of the wf289e8dmb zzel 7r,aEarth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a lo vxe 6 6piam0k(.wd8o. 1kncmiw circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (ik1 .nk epi.8avmo6 06dwmcx (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 Earth. It is o 70b g)lkuvm.qbserved to have a period of 89 min. What is the mass of qg07blmkv.)uthe Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamet 2o5 )pl( oa +rb) 7+/cymybdh/ymdvller of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Juphg3uey5) kc uws8t: )titer orbits the 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 plan9:t 1vbya2e c7dvz ;h(k kn)ynet 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. How1:n92aznv k(kh; cd)y7 yvbte long does it take moon B to complete an orbit?

  The planet Jupiter ish5 muu lc 05(ad4md/ e2hzlnvoo16zd 5 $7.78 \times 10^{11} \; m$ 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 average in) og cgyywj/5s/e)h.p0z 6cdistance from Juz)y n.c0jwg/h /gi c)eyo p5s6piter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)