Is it possible for an object moving with a constant swd 3g3 (7lzl l7vgj5tpr rd9f-peed to accelerate? Explain j z-d9wtl7flv3gl3gp r5d(r7 .

  Consider a particle movbup i0 v*,m )ub;r(ntcing with constant speed such that its acceleration of constant magnitude is always perpendicular to its vbum0pn)u*c b( tr, v;ielocity.

  An object moves in a circular path at a c8mhw ln n2umiyx5ed(/ b+cj +;lyq,-vonstant speed. Compare the direction ofc-wjln , u/5ybhnvmm e8 xi dq+(l+2;y the object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the acxo: x35j(jps ( *kcprwceleration iss:* jo3xp( x(krpcj 5w

  Consider a particle moving with constant speed such thahy fh6 wh(-;jd(lxr c;t its acceleration of constant mhl6 ;jf-r(wh ;yh(xdcagnitude is always perpendicular to its velocity.

  What type of acceleration does an obj k zrzdr(01y2cect moving with constant speed in a circular01zc 2rz(kydr path experience?

  What force is needed to make an object move6kmp i(d7oh5dw1 zsf y2 (z*ac in a circle?

  When an object experiences uniform circular motion, the dicf kfv 30+2eaprection of the net force isfpfcev k+ 32a0

  A roller coaster car is onbl4es qjsh:ia0u6. , 2z3dgko a track that forms a circular loop in the vertical plane. If the car is to just maintain6zjsdhegi oa 03:uq2. lk4,bs 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 a track that forms :zm/*w2msxaz9yapc . 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, wha* xm9p.:w2mcs zzy /aat is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semiq/r nbldx/6v* -circular arc until it is going straight up. Just as the plane is at its lowest point, the for/qb* /vrdl6xnce 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 curo8 z;8n+fr1j4a8l4 u govlz ltve 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 constantv*gvrvfda9h p:3 n0 +o speed v. Then it goes around the same curve at half of the original speed. What is the centripetal gh3 va+v0:np 9dfor v*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 speed v. Then ita9sd+w)yw ipx-d2q 4o goes around a curve of radius 2r at speed 2v. What w9od)awy qipd+ s24x-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 x x87m :dlp.eccurve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if th 8ld:mpxx. ce7e horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curve s/dkr*az*u ue1+2.iioa(rdbs on a bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (id/u+*ek.ubis2 1( daoz a*rrno friction 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 con ,m:r)vgj: 6pdf 0wng6mzkmc6(;hj jvstant, 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 6)kvjg(r nmp:w6j:zh ;, mmj fv 0c6gdturn. Why do they do this?

  Is it possible for an object moving around a circular path to have both cer i8b(tz1+ ymentripetal andze8 rmt(+y bi1 tangential acceleration?

  The gravitational force between two ona3yufv5ocol+* b* g/ bjects is proportional to

  The gravitational force between two objectsdirh6b4dxf tw wwb :wsp 7-) knk1f-:: is inversely proportional to

  Two objects attract each other gravitationally. If thegx2q/ :fj/dsbqsypr.pi *bq0s23 3jo distance between their centers is cut in half, the gravitational forceq*gf x2ysp i3/ :sb 3/.2soq0 rqdpbjj

  Two objects, with masselr/0cdwg: p7n s $m_{1}$ 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 ma7chuc /4cao n6sses $m_{1}$ 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 gravitatefg3d- lu(p*3 wxlpj8 ion.

  Compared to its mass on the Earth, the mass of an object on the Moon is c82 zno./ bpqo/45eowlg r .d2ke:9iub tkza4

  The acceleration of gravity on the Moon is one-sixth what it is 7awoilh *i 89xzrt:)won Earth. An object of mass r8axwi9*)thi :7wzlo
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth,h5fevz:kwt3 d :i(/rh 3jyxi's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull of Eavz3 2zg 5 eag:/wq3c*xl,cn;3cy q itjrthcwzz;:/ 3q acj*,3vq5xn 2ticlg3g ey's gravity?

  Suppose a satellite wer0) ph4.5toezmipvwk6-1b om3c2 ixbj e orbiting the Earth just above the surface. What is its ceni i )hv p3wbmjke b2cm14.tpx0z 6-oo5tripetal acceleration?

  A hypothetical planet has a mass of hadj 4/ ns9zh79 f6rv yw8;shsk-cw 5dnelf that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet - 7nwhd r9s694sh 5ecwns;fk/8z vjydin terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth wh l(xy1o-2 pwvgat it is on Earth. The radius of the Moon is onew- y2v1gx opl(-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the .k :ohe+laibe t9cx/b k)4s* zsame surface gravity, but planet B has twice the radius of planet A. If planet Aczx/hba 4.:ke+tlo b sk )9i*e has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass ob cqk+9j7dmvfgaiy:f96 sx4( f planet A. If planet A has radius r, what is the ra+j b(gkc 9d4s a7xm:6f9i fvqydius of planet B?

  Consider a small satellite moving in a circular orbit (radiu3l:gj1gg m6 imk a+h1ajw ;w+os r) about a spherical planet (mass M). Whj +ik3 laggog a;mj+1:1w hw6mich expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. z 8g5-i ze h3squ -91jx8bxrxmnq2 az*Compare the two1*qjm8xqiaxzx8-e-z5 rnbuhs 93 g2z satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compvad*do2w 7l+ wc .u7waare the reading on the scale to the persolu d77.* vwacw+ dowa2n's true weight.

  Who was the first person to realize that the planets move in elliptr/ofy,1 tw 6mbical paths around the Sun ,byw6tfo/r1m ?

  The speed of Halley's Comet, while traveling in its elliptical orbit aqowb9s8jp(2z g ;qv6 fround the Sun8;(2f sq9o zv6gjqbpw,

  Let the average orbital radius of a planet be R. Letkra oc8i+k vk 1;(f mye*nq8i9 the orbital period be T. What quantity is constant for all planets orbitiiq1+kky9 *mcrf;(vaen ko 8i8ng the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromsow m*8sq)0gd eda, 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 be, c)s08gosd* wqm ompared to the Earth's orbital period?

  The average distance from the Earth to the Sun is definede /zy 1 w *kle+cw;ww3tpm:m:q as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's awlwc ;1p 3y:emw t*kqme+/:wzverage distance from the Sun?

State Kepler's laws.;5 dfc0t *sed k/azcp)o3 dir*

  List the four fundamental forces is( -e5qe(xax/ ax/a l4lx e/kbn nature.

  An object moves with a constant speed of 30 m/s on a circular tjpk.)hwf(2 q nrack of radius 150 m. What is the acceleq2jn p) wfh.(kration of the object?

  The maximum speed around a level curve is 30.0 km/h. Whs7r)4j3ac 15ytbwl o7j2qnd,o c srg5 at is the maximum speed around a curve with twice the radius? (Assume all other fwj53rn7 24q cyagc 5 ,b oodl7rs)jst1actors remain unchanged.)

  What is the centripetal acceleration of a point on the per) niefld5(m qdk6r9j4su+yg: n9rj0simeter of a bicycle wheel of diameter 70 cm when)mdlkj 0r rsj:ei5n6( +u9dsny4f9 gq 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 axis47 ejntz*8e rw p ci6m/*io*du. Whate6ou7 * */84pm iiectz n*wjrd is the centripetal acceleration?

  How many revolutions per minute d whir9im 3.u/must a circular, rotating space station of radius 1000 m rotate to produce an artificial gravitih9wiu r m.3/dy of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96 lpx*y .c: ,xxnm*n 8ynoi.d+o.5 km/h.n*cxm on ox p..l *8:i+xdy,ny What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m st7gt(q cw6awp rw:5taw*l l2-nring. The system is whirled in a horizontal circular path. If g wwptrl* -nt a:65cw7 (a2wqlthe 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 whi qncsrnb,-;cp8xh;(jrled 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 speepxq-s cc8(h;bnjnr ;, d at this point is given by

  A stone, of mass m, is attached to a strong string and whirle1ctek) gy2yng( c5a db+1qpc1d 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 weightb1n ypce1gcck g5a y2(1+qdt). The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences a0k,wawa2 rq 7kn acceleration of 4g when pulling out of the dive. What is thear,207 a wkqkw radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in whictqs j3h5iyd+(kriv. ,h the center of the loop is beneath him) of radius 3200 m. Atijk.(t ,i+rvqd3h5y s the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot c ;r8shcfy3cv k tlq3b2y)0p yl(/;p udan stand is about seven times his weight. What is the minimum radius of curvature that a y;spf;b2q/ )ycldk8tc h u p30lvry3(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 horizontall6mu,0 n: y f3un m;opmy*adm8idr6g9v,l*yx curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Asso ;n,ya,l638xmvm0nlu u*9myipyg6r* m f dd :ume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of ohn qi24k:,bj radius 50 m with a speed of 20 m/s. The centripetal force pri,o4 k:jnbq2hovided 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 sp)*abz 3 a+ pc2fgs:7qq2 ohql9 pwivm-eed of 14 m/s. What must be the minimum coefficient of friction between the tires and the roadva+q92bgm2pio c fq *:hq3p - a)w7lzs for the car to make the turn?

  A car is moving with a constant speed v around a levq, 0sr kp nzr)oyy5z:6el curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the c5qonyz:6krrz)y 0s, p urve if the car is to stay on the road?

  What minimum banking angle is5o( e8wtxq0 i(s w.kjm required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skiddwmo qs0j ktw 8(5i(e.xing? (Ignore friction.)

  A horizontal curve on a bfwy x-ze l77v-rw2tj4obsled 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 an angle of hyy,awxue2*bu5a dgkg a 6u)3;4.rmu $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ba wr/ -bbi*x8lg-td m9anked 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 unvvi cw u0jg 25k n,9y;c7fb1cniformly in a horizontal circle of rcv2nuc9,cy0b 17gk nj5 wf;ivadius 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 toet g1wlryv-w(4hw h4+o9 r+r zdt4vp+ a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numetegz+hrr-19wp+ 4 lw(th 4r w4vvyod+rical 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 pea,1 rmdp0 t-kroton 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 omb9w:13 mnhd(kmfyc+.9 1 k 2x+ 4qxhqhtd squn a 70-kg person standing on the Earth, due to tm:u. c2 qtm+n1(wsdm9 qqhybk3h hxk9f xd+ 14he Moon? The 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 masses is F. If the masses aiimfnt9 n2 )k d 0gg3,gtyc,q5zf5do3re moved5, 5i39fg d,0qd 3n2yzktgonm ft gic) to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towajdyiczoxg -j/vn/tn( )d7x8+.q 0f g4:st ultrd the Sun, at what distance from the Earth will t z-. iy+7xd tjgtvu(o)s n j0lgx/d8f:n/ 4ctqhe 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 Moon 1iel2 qv7vgj s1;n k5xis $7.4 \times 10^{22} \; kg$ 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 abovkru6rf qe8(h 0/2emzne the Earth equal to thk82 ee/(6mur z0frqn he radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the eu 3lgbi 93y7rp-zwu2du v.w )Earth's surface will the acc-gdu2beu7. rv3yi9lw w3pu) zeleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars a cg;cca,m6,tct a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfacc,6, tgc;m cace of Mars, is

  At a distance of 14000 km from some planjm h7k j.13r7eh9 jqrwet's center, the acceleration of gravity ij7.j7mr k1h re3qwh9j s $32 \; m/s^2$. 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 tgk v7tsg977c nhe Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, whatgs9v nk7tc7g 7 is its weight?

  By how many newtons dov4kigw :75:h9 iwfagues the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius oa:9w 54ig 7ikgh ufw:vf the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite ,)ya8jmibuokr .p6x hq51 om8of mass 100 kg is at a point 3r above the Earth's surface. What is the8ou5qk o 8y abh rix.1mpjm),6 satellite's weight?

  A spherically symmetric planet has four times the E;e0qo-p+f*.h ) ycyh szxch ;oarth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the sury sq x;)-oheco.*+hpy ;fc0hz face of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, yfhq; m+k6p1n Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass o1kfy+;mn q ph6f $7.36 \times 10^{22} \; kg$; 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. :rh)hrkg ,dstprub:2m *k; gj:w+ xc 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 orbit about the Earth (i.e., it just skl1* ys 5hnvx:4:bt-cym1jroiims the surface of the Earth). What is the speed of the satellite? (The mean radius of the4hy*1n yt:bxr:ijomv15s lc - Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low ci: . flku oz*wo6my7m)ercular orbit about the Earth (i.e., it just skims the surface of the Earth). How long doesz* ) :wyuo6.em 7kmlof 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 Euu4jjuv *u,:k 5zbo2kxt(ol *arth. It is obsjuk,vx5 u *j bkt zuu4:lo(o2*erved to 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 veoyyd e4t i;m35:x s0orbital 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 planet with a 4g-wz+dz5h)xssc k x5 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+;a (f/lsd)rb/2 d*xxf)0 f nhhbp mjc8njz 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 mof ;+*h0fxh 2d/ szrlbdbxcmjnpaj () /- naf)8on B to complete an orbit?

  The planet Jupiter i6o0tvc:ipokxp wf n0 .fs8(j/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 12a8n8rvlzoa/c 7e:g:w zq4 t1 a years to orbit the Sun once. What is the average di:cat/g 7z evwz8a4o8rn: la1qstance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)