Is it possible for an object movinf-fq7a x(eiv,g with a constant speed to accelerate? Explainv,a7f f-xqe(i .

  Consider a particle moving with constant speed such that its acceleratio.lrc t+ f bg,/:dzj-3uwa*hven of cons/:* fuvdz3lhw.-c, bejr g+ tatant magnitude is always perpendicular to its velocity.

  An object moves in a circular path at n8 * qzorzbkw(d8v2,da constant speed. Compare the direction of the object's velocity and acceleratd(n2 r z*oq dvkz8bw,8ion vectors.

  When an object experiences uniform circular motion, the direction of th f, t uio;h,e2oj8jr.ze acceleratio hej u 2oj.tfi8;zr,,on is

  Consider a particle moving with cor6j 5i. fczm1rnstant speed such that its acceleration of constant magnitude is always per mirr56jcf .z1pendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a cirx r;h:qe kj..bj6v*zs 3obnd9cular path exper 9v 3.r.bbh;xjde*o s:nkz6qj ience?

  What force is needed to m /-ydifjez6 sx6f5dyi h5gc +,ake an object move in a circle?

  When an object experiences uniform circular motion, the direction o4jxwhg il(b*z:. yf. sf the net forcexy(hwj*4 gzb.sf il: . is

  A roller coaster car is on a track that 5hd i:v*9mgs0eur*teuvg9; nforms a circular loop in the vertical pl ug5s:e *m;u0nr*9v hdv9t igeane. 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 ojaq1q9;d z.vbldy.l ;n a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain cona 1zdj dbv;9yql.q ;l.tact 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 follgnbtl,j )o/e; z (nrnal:q pd94/oh1qows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on jn dl r/:)opt1qb,neq ;(a 9nho4gl/zhim 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 gtiihk( gz))siliqv :l8cj,.24 dla 6curve 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 radius r at a constant speed)ue(uouab g9anu4 z. 1 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, compared to ub oza9.ua(nue4u )g1 the first time?

  A car goes around a curve of rows9-zz8a l (vadius r at a constant speed v. Then it goes around a c a-zvz so(9w8lurve of radius 2r at 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 5d+bdt4c5gsm tvyv* *egb8g3a banked curve of radius r with speed v. If the road is frictionless due to ice, thevde ys* bg5b4cmt 3+vtg 85d*g 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 banked at the same angle, but one ;7ny tllpfvr8 8,,*t :z* luu jvlx-yuhas twice the radius of the other. The safe speed (no frictionjvy l:nlpt* , 8t-fl, xy7ur8;vu ulz* 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 bobsled track is not constant, y1ymw (( w/xdsbut increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climy wsxy1 /d(w(mb 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 t0u7x44yk, r buufjj0d o have both centripetal and tangential acceleratu7r 4jj4fxyk0ud0b, uion?

  The gravitational foyy1kp- ,sx.euzr 5 i/brce between two objects is proportional to

  The gravitational force between t...e mlcsqzd ihj2zmf26tm 3y.e4q0m wo objects is inversely proportional to

  Two objects attract each otheqmx4*14b- reatpi 9x ont9q: gr gravitationally. If the distance between their centers e* 1t4o 9mx:ri-4 9qn pqtagxbis cut in half, the gravitational force

  Two objects, with masses my/.wxlk8z70zco4 bz$m_{1}$ 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 massesc xxxjh43 *(veci9 w/u $m_{1}$ 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 univdao/1 -jug8tgu/z +npersal gravitation.

  Compared to its mass on the Earth,kyuv7d j*haaa 6q :0h1 the mass of an object on the Moon is

  The acceleration of gravityx43be,ta *zwu on the Moon is one-sixth what it is on Earth. An object ou ae3ztx*w4, bf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface,uugq4-d f.dm9xug 4oj(y2 rz 7 the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beu)4qrs vk.0- q8nt8jeqo0v y 1+sqzhk yond the pull of Earth's gravityo)y8 .q-t1nqs sv4rh+0qjq08v eku zk?

  Suppose a satellite were orbiting the Eatl3j7 s-iioxl0h0o l*rth just above the surface. What is its centripets*hj7xlo0 0i tllo3-ial acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twinrt ufw 15 h( o/uou1;7q+ihxpce that of the Earth. Whaux 5oh whuu( 1+f/17 rot;nqpit 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,ql yt5:e7zfkz;u gi; is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's makuezqz y7 ,: lt;g;i5fss compared to the Earth's?

  Two planets have the same surface gravity, but pla5 w6dqy z a3 vkl)3;jcw)c*lvh7kg (fxnet B has twice the radius of planet A. fyj)l6v a k wxhdczgvk)cl; q( 7*5w33 If planet A has mass m, what is the mass of planet B?

  Two planets have the b7/g4lgi(hgr.-tksp p m3 b0hsame surface gravity, but planet B has twice the mass of planet A. If planet A has radius .i/hlrg7gkb(p-m4 t3gshp 0b r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbi6.x /yj wd6rjwv;*f*p) m wpakuceber9*5 5mz t (radius r) about a spherical planet (mass M). Which expressiop dc eemy xwfj) 9b*56mv*r/rw;ua6p5z jk*.wn gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, aqmoix767lp0uv )a e4 and rotates in the same orbit. Compare the two satellit)4 qp67 ao7vl0ieuam xe's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compao,wb((53ssiif- dcczre the reading on the scalis53f,si(z d bowc-c( e to the person's true weight.

  Who was the first person to realize that the plane mlt9x j0li15yts move in elliptical paths around the Suni 0j91lm5tylx?

  The speed of Halley's Comet, while traveling in its ehu ;c1wy qr3fav hp-.7lliptical orbit around the fph .1-vhru;qwacy37 Sun,

  Let the average orbital radius of a planet be R. Let the orbital period be T. qn3i5x nhoh xem,l4/l.4 cec-um1x. z Whl 1m4c zh-cin. m5 .xueh4n /,e3xlxoqat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to org;n -lxu p- fxe(zfm:5bit 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 our Sun, what will the period of revolution of that new planet bz :fxg;np l(5-fue-mxe, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronos( eqwyi:,ro e/fsp 8n)v9t .fmical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the S(s .8fwteysqi ,9) vfern/ :opun?

State Kepler's laws.2 bct;trx/c cf6a g4d:p3d6;e3p bsx d

  List the four fundamental forcesf,(vljdbf 1 7l in nature.

  An object moves with a constant speed of 30 m/s onpc hgrc*-/ yl*5s2 zpi a circular track of radius 150 m. What is the 25 *hpplcz-ys rc*g /iacceleration of the object?

  The maximum speed arotid) ytw +oj2su4)8i gund a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factogw )s4dy+jt82ot u)ii rs remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a biceadjuqu:8kcrme4 2rf, 3*tmxe7v )4cycle wheel of diamete2x kd3,rmua :remtv4* 7)cjc ef8ue4q r 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.0qvapbc1 yuxn,-. b7nl/kq -t(a sl. 5j0 rev/s is located 0.200 m from the axis. What is the cen( ,bqlua..bs1at qnjxnp5l-/c7vy k-tripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of7: 1 bznds *s9z)signyyq/2d y radius* z9gi zbnqy:7)y1s ydn/ds2s 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 mdlj/-u7*qz crd+t-;udx )a 0ek( exkp radius turn at 96.5 kmxq-u rd+e e*dl/z7k-pdtxj)u( ; 0cka/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirledo y;d)tfmh) 3a in a 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 dyt;3f ah)o m)break?

  A stone, of mass m, is attached to a strong u izn6sipy83 9string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 t36pn 9iiyu8 szimes 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 l4d k:9 r9cehnwhirled in a vertical circle of radius r. At the exact bottom of the prc k:de9nlh9 4ath 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 o 0 01;/ aaabvd ztgnl(tr+eo ey*jxr4t*j e55lf t *(eb4et rye vanz a0lgtl51a;/ 5o jxj+0r*dthe dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the l5l ptnb.,e2c745s5t vf wv +kig nfai2oop 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 goin5v5bw 7+pc f.t2k52sgt, iia4nvf lneg?

  The maximum force a pilot can stand is about seven times his weight. What is n y(l1qcgcfo(l+d yl(0k(;wy the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at ao( +ln(yl y(l1wgk(fyc;cd0 q speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires onhmhe5h*0ym a( the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction hm5*( mhha ey0between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a sp( ;yy ziszy0x(py(mo t/hv88keed of 20 m/s. The centripetal force pro vztmzyx;(8s0o(yp(8 /hk yyi vided 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 11odk6m3vdu 2g4 m/s. What must be the minimum coefficient of friction b2u61 3vkg dodmetween the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a h+5o0xqz84k ) va p.onwp4e kwlevel curve. The coefficient of friction betze+h o.kp)8 aqpxkv 454wwn0oween 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 negotiahrln0::( jzsi-yalz /r5qic* te a 100-m radius turn at 35 m/s without skid:ir lchs q* /5r(0- az:lyznjiding? (Ignore friction.)

  A horizontal curve on a zdqd643r1u,esoh t3n k;q(m p 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 curveev:s)3 h mi3k d rus/iu13rrj( of radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m imx f22rk e8ji7xg)-n f/rtx8ssb79zis 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 cfvky1 f/k7ko9 ircle of y7kk /fvf9o1kradius 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 ungl/ p5lre;i+t iform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical/gi;lp+lr t e5 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 t )x:aqbzb+g9of 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 -6hgid1g .0tdw ct)la:7g trmstanding on the Earth, due to the Moon? The mass of 7ag0-t. g)r 6whd:td il1tmgcthe 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 tw:3guhy ind qq8aiwc.0 w:oblp, 0ry-/o masses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive f/ whcli,q 0oi:.wua08 bqr:ydp3- gnyorce?

  For a spacecraft going from the Earth toward the Sun, at what distanc1*ohvir /vn:fe from the Earth will thovhi v *1/frn:e 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 Moonxw9yku;jr hbkb; 86g srxqh o20o22x( 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-1-+8z aj xnfvlwalk" at a distance above the Earth equal to the radius of the Earth. What is lx vnj+8-1fzaher acceleration due to gravity?

  The radius of the Earth is R. At what distance above thzvt ):dg g -40cuv jojyw;6.ars**igle Earth's surface will the accelerat4gi .;slv: rzv*a tc*0y owg)g j6-djuion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times thlajn(o: *vha 9-x8cqhe radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfac :9olanxvh(jahc*8- qe of Mars, is

  At a distance of 14000 km from some planet's center, the accele)s85egg .z6pka0g 9 pk ,bca us2mm*flration of gravity is as)2 gfa lm egku*g6, bmp59c8s z.0pk$32 \; m/s^2$. 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. If 64 )a9z un. e(tpijqhsthe object is raised to a height of 3r above h)p4 (.i6ts ez9a nujqthe Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg personb+5jhnro or700 kk4rh change when he goes from sea level to an altitude of 5000 kh +7on kjorrb4 r5h00m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 10.1kl 9tj1z yxbfk*9o tw:t2xw 0 kg is at a point 3r above the Earth's skbowwx.t 1 * 9jtl2tkf9y:z1xurface. What is the satellite's weight?

  A spherically symmetric planet has fo m9xtsq bdll76k. ii+2ur times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the sur d26kli7q i9sx.l mtb+face 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, whom 3pzo12yb1 ith the Earth between the Moon and the opz2m1o3h y 1bSun. 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 v;70fc y h4zby9l-mccsp( xp .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 orbit about the Earth (i.e., it just skims the 9us,s 9 yx8xbksurface of the Earth). What is ,b 9sx8sk9yxu the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orb48gsu t;t4r)zv7n 1fj m;ok( bq;atgnit about the Earth (i.e., it just skims the surface of (4 ak)j4gt umsqgbt;; 71zt8vn;nf orthe 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 orbit 230 km above the surface of thwni w y65 d8t-q )jtr6r 9cw-8zssfdz0e Earth. It is observed trrf0cw8d 6sds8q6zjz9wt)y -i-5wtn o 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 orbital diamei t)lpzdfncar.3 h* u 4w/*xk8 9ln/prter 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 orb 9lve,w1:7wtp hu ufqjs978qrits 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 planet in nearly circular orbits. 4s 5w3srhwkqjq36l8 x Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A tlwr s83hq6j5k xq4 w3sakes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ij2 66uorst:cm s $7.78 \times 10^{11} \; m$ 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 averag;fr c-bu* 5ue;ap g)zre distance from Jupiter to the Sun? (The distance from the Eart*u ra-c g;r ;pue)bfz5h to the Sun is $1.5 \times 10^{11} \; m$.)