Is it possible for an object moving with a con*u mb/s gb whyc4;h5u3e: pyr:stant speed to accelerate? Explain.p3gh w:u/:eyyrb ;5m*bh4cu s

  Consider a particle moving with constantq j+qgtjism1 g a0-xm8fq+.5 a speed such that its acceleration of constant magni0+.x mf8ggj-mjaa qt si+1qq 5tude is always perpendicular to its velocity.

  An object moves in a circular path at a cons4ab;ifzbrjv 7o df ; d(05 p0)vbo.zeytant speed. Compare the direction of the object's vel0b4zbaj7vp;(d. ;de)5ovf0 oif rzbyocity and acceleration vectors.

  When an object experiences uniform sj*dx tj/s *go5t; w-ucircular motion, the direction of the acceleration jwdx -gtu*;o s*js5/t is

  Consider a particle mo,+s4ll*s(hj)bb8vq 6 /v4fsn l.jln pfr m5fu ving with constant speed such that its acceleration of constant magnituden (ms)b+vqf/6 hl*s.n8s lf4r5l4vjlp u,bj f is always perpendicular to its velocity.

  What type of acceleration does an objecnfj+d(v8 x :5djz hkv1t moving with constant speed in a circular p:58xzhdn1vkfv jj(+d ath experience?

  What force is needed to make an object move in a cisubkw g(w +j(7pf6 86- ltaeo)tt5mkmrcle?

  When an object experiencq-+ wnp+tlbq, es uniform circular motion, the direction of the net forcen+ +pq-wblqt, is

  A roller coaster car is on a track tblrjp +07 jw-nhat forms a circular loop in the vertical plane. If the car is to just maintain contact with tn+w0 jrbp-7jl rack at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) istpgpupu *c07n4ob - 9j on a track that forms a circular loop (radius = r) in the vertical plane. If the cj9 uugt*-o4p ppc n07bar is to just maintain 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 mr*93 jqkq v4la semi-circular arc until it is going straight up. Just as theqv* r493jmlqk 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 curvc xz:i3f/hs7l;:ku djj 9jgv: e 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 radic.qz0a tq wwn: 9b9rk8 )hbn+lus r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal f) qwlba:hcnq 90+r k.8wbt9znorce on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a cu i opq4+azqg9:pv1yq8rve of radius r at a constant speed v. Then it goes around a curve of radius 2r agq oqaipv9 41yzq: 8p+t speed 2v. 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 around a banked curve of radius r wit41 tl/qatntqza g,9,ph speed v. If the road is frictionless due to ice, the car can still tap, tnq gtzal/,149qnegotiate 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 banked at the same 9b7 ueinobxwt. c yrzq 5+:yn0 c1-.vxangle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller b9 vyc7 c+1.:b i-noqzxeyrt.0 5unx wradius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olp5h 8 ujk0yxv4ympic bobsled track is not constant, but increasesjxp4y ku 50h8v 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 this?

  Is it possible for an object moving ar 4y6ws7 +wfv6m02jvo,p qyamhound a circular path to have both centripetal and tangential accele+ wvmw6yp j2hyosf6v7 q,a 4m0ration?

  The gravitational force betwee;:m 1 0jkgxlmfn two objects is proportional to

  The gravitational forcaopx1zpjlwp (f r840)e between two objects is inversely proportional to

  Two objects attract each other gravitatydslc 1b8v0q15ni tj /ionally. If the distance between their centers is cut in half, the gravitational for1bjy0s/ln1 ciqd 5 v8tce

  Two objects, with masvpi;hjy : +d/tses $m_{1}$ 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 masses .w *5a zvx*l:uy f9,cx;fvlxk$m_{1}$ 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 ukb( 5tmtz2, gpniversal gravitation.

  Compared to its mass on the Earth, the ,xu(f6 hx7ddfmass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it *r4ru4/dbuda. 4pro o is on Earth. An objec.4 ua/4bdu*4rrodp ort of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surl*zt3wtydg pl1-idi 5+u4fjb+:u* h mface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond aw(lq4 q/7m fkthe pull of Earth'qqk/7fl( 4amw s gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Whatp1 ,l.srco, dz is its centr,.od , cszpl1ripetal acceleration?

  A hypothetical planet h xb7/s:dr:p/ocbm e.aas a mass of half that of the Earth and a radius of twice that of the Earth. What is the ac::oep /xd/mca sb7.r bceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity onzs ek* ,3w/mwk v)58zuicsw l8 the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth tle k*s8uiww),/wkz583m szvchat of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surf 7 f1w:.rmgn/ngi yc3face gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of plannm7:fcwg rf n.y3i /1get B?

  Two planets have the same su age,9+3y6sz3mcakr8a un/ic rface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radingsrcc y6i3u 3ekaz/a8 a,9+mus of planet B?

  Consider a small satellite moving in a circu:s l lg muuyro55o --fap1saf0,d( hu2lar orbit (radius r) about a spherical plane51 agpu-mh0f o sd:u alo-uf(l,y52rst (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates inv1ur4y: w-vpo the same orbit. Compare thvwr:1opv-uy 4e two satellite's speeds.

  A person is standing on 3cp+e-ez0zrr,m 5 e2usob 0 qya scale in an elevator accelerating downward. Compare the reaq+,0 5 se3rz-2pyrez0em cuboding on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical pathscaq1aw 8r fokr774 v;a around the4 w k7a71vqf8rcoa ;ar Sun?

  The speed of Halley's Comet, while traveling in its d guo *qe31kn/elliptical orbit around the Sun3e o/q*1 nugkd,

  Let the average orbital radius of a planet be R. Let the orbital p9hwtznksg vr.*8 *-ba sii*v +eriod be T. What quantity is constant for all planets orbiting zv r *nvbik-a+ g9 s8**w.thisthe Sun?

  A planet is discovered to orbit around a star in them kv -1pi qbr)gtu1v84i5g ai4 galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the period of revolution of that new pla -itrva igb1184 v5 qipm)u4gknet be, compared to the Earth's orbital period?

  The average distance from the Earth i3mz/l:, )ryjgoz*bi to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroidriyi3 *ol /zj:z,)mgb's average distance from the Sun?

State Kepler's laws.bf 5 e/mmz(dct:m 0yi9

  List the four fundamental forces in naturyz7z)x+;ied qrl/ah;i(o o-we.

  An object moves with a constant speed ;ko0x ;wozze8of 30 m/s on a circular track of radius 150 m. What is the acceleration of thko;ox;0zz 8e we object?

  The maximum speed around a level curve is 30.0 km/h6zguntf +1: mqnaz4e4. What is the maximum speed arounz4znfta n+6qegu :4m1d a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal accelerationzv-qfz85 *be ke m.0ot of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bi08fb- z*z eo5 ekv.tqmke is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locatx)au ffrjt9;8 kpzs9lo +y95y b2m5z jed 0.200 m from the axis. What is the centripetal a9pxy y9jf u )9;8skaoz m+rjf25 ztlb5cceleration?

  How many revolutions per min (mix-2q bbv5ij2 waa4ute must a circular, rotating space station of radius 1000 m rotate to produce a- m5 jv wia4xbi2qb(2an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiu*meltxq(xd/e7dgk .nzc 8x9oc:y 7y:km::rc s turn at 96.5 km/h. What is the centripetax*rt.cx( gxcce ml 7qz::m: y78o9ke /kddyn:l force on the motorcycle?

  A 0.50-kg mass is attached to the e7ydl m6(h(u,,trf+ wlxmfr e cx24z9jnd of a 1.0-m string. The system is whirled in a horizontal circular pate2 d fux (4l +7yx6z(rc,mjmhlfwr,t 9h. 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 string and whirled in e(c: ogaa-/vh a vertical circle of radius r. -oh(aegv: /ca At the exact 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 *b* olvaib19erfqod05 )uy*r a strong string and whirled in a vertical circle of radius r. At the exact bottom of tbv e**yo*df0qa9bi5 ) 1r rlouhe 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 acceleratio*ym7)k5xkmst6 ad nyrq6su) o3w8jp ;n of 4g when pulling out of the dive. What is the radius of curvaturekjxmtd6kp8; 6yor5mq3w snsa*7u) )y of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the osezv.a+bq, g 1m- jx;loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat wiezv+m o-. ,1bg ja;xqsth only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can gxm:,/, qyq/i ;fs suk n6k2t:uqcse2stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a ver i,x; q m :k sy//q:,tgsk6usen2uq2fctical 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 tijs2a1 w-m5lz hjg,06tn eev.gres on the verge of sliphmse-jv.n1j 2gzewgl6a0t, 5 ping. How fast can this car 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 raasqyrqv2dx1o iu/8:96z6s hkdius 50 m with a speed of 20 m/s. The centripetal force provi sz2ohaxd q8vr/ ykqu:i16s69ded 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 m6i-fvq yg:l: ch-o2erust be the minimum coefficient of friction between the tires and the road for the car to make2vcg::6 oe-qry lhf-i the turn?

  A car is moving with a constant speed v around a level curve. 4x+aj486 zv en t92 bcvtifim* 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 on the road?894nit4+bmvji f*avt 2exc z6

  What minimum banking angle is required for an Olympic bobsled to negotiate a 100pc-u2/reetu8 )t a b5z-m radius tur/8ctur bea2-tz)p5 ue n at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobs(sruygtl 2 n eum6;8 m()mrdh6led 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, o+ j78xs*p3 c/sbyj jsbanked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 w( rq b qod0,as/swtl3hi3ve6hn)/p 0m 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 ci/t 1i8kzcaiso60md:z o: 5szc rcle of ra01 ot:di sma/zi 5zc :z8okcs6dius 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, 1; )usrswbqq ; 2k mr5b;zryu2a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (oqm rb5r2 1qs2;s kywb;uu;rz )nly 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 o70g5u.qi s t06z-yo8jj vjy vvf 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 Earth,8l7 qn(oqpl,k due to the Moon? Th oqkn,(87q lple 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 force between two mass5 6xkb8ge):gdw ;lyetes is F. If the masses are moved to half of their initial distance, what is lx b g);tdk6 wy:eeg85the gravitational attractive force?

  For a spacecraft goiblqj5.y+o z,d ng from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and th yl. o5,jbqzd+e 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 Moonx,0a;orlstp ujyd iy) n- .+ nhct*y3; is $7.4 \times 10^{22} \; kg$ 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 t ,gq;am 8pko:1c;oanEarth equal to the radius ao cagkpm;o8tnq ;,:1of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above theogzqx8 /l.3j /sjbuv1ei (kb 33dfz1 l Earth's surface will the acceleration os13kgo vxqz bu1/ j8ll.f jb /diez3(3f gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface y8p7c 1czhferue0j8l rivpr0r43+,u; 4qu ev equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as c u,crr3ucrvlv f4 zyj ;+7e0uq4pr08ep e8h1iompared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from somezmx-fz u5zrt)xj*zrk zo/ c3og/ 0..g planet's center, the acceleration of gravity is 3z)mf u/. r /*ztckz0gzoz5oxrx-.jg $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N onsfnuhfj ,t zi/u9*( 6k the surface of the Earth. The Earth has radius r. If the object is raised to a heiff(ns 9/,jh k6u *tizught of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes fromi q-xo9xea+q rxx :cj*1v,cd- sea *dqv+:j9 -q a,crxci xoex-x 1level 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 above the E xpah1inscgwi ,2i 29oy63o.k arth's surface. What is the 39g 6,hs ii22ckw.xpan yoio1satellite's weight?

  A spherically symmetric :5/3*d cvu wtkl3ooo b4rj2 i*cjt 9rl4o0f ozplanet has four times the 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 the surfaol0ol wor29jzi 3 jf/4vd tc:k 3u*oob *4rct5ce of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lh ,9 uc9bvvv/*n u5ev-p86oxy (wyd+rx*ewcbie on the same line, with the Earth between the Moon and t cb- *8p(y,u9wxevo + e vxbv/cr9 yhw6u*5nvdhe 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: eupk;uce 7s mkc(cx,5ndo)4 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 circular or p/9 v-n)zx:y melwe2gbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? mz)l:2egp- y newxv/9 (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., 32uzfnt c (6nj 3 8wspsj/c:dls8y-bm it just skims the surface of the Earth). How long does it take to make olnbyu3j8( sndtc6 w:m-sc2zpfj8 3/ sne 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 surface1v3*g7 lkyloe*zk:5tddic0 sb06 t ft of the Earth. It is observed to have a period of 89 min. What is the mass of th:og7blyf vli*t0ck3 de5td01t6* zk se Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameteth :i0h orzrqifcv wpti7w;*;c c.vn6p+2 s2;r 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 plane ru.)1tr qehuq l.o8pfbe3q/-y)mis5 t 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 rad:( tnqxo ch:z,-gv q2sius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B :o, q2gqvz: - tcx(nhsto complete an orbit?

  The planet Jupiter is/t 5.vq0: ke snvo(tf39e ykcf $7.78 \times 10^{11} \; m$ 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 S: loek0 dk0(( gwdpd*s;xbl-f7 x)samun once. What is the average distance from Jupiter to the Sun? x dd-0l((7*sl)e a0 bxkod g;sk:wfpm(The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)