Is it possible for an object moving with a constant speed to acc.n3 6z p1nj gh 6snx13*pyooudelerate? Explain.nzdp6n6 n113hyjog* xpu3s o .

  Consider a particle moving with const-obqdh i 87;cvn2 vz/yant speed such that its acceleration of constani/yqonhvv; 2c 7b8 z-dt magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the directionwrsl2 a-ssq31 of the object's velocity and acwsrq2lass - 31celeration vectors.

  When an object experiences uniform circular motion, the direction 3 blg6l1/*c x b bvnmdin5:-mcof the acceleration nx3 v-5l bm cli1dcb*g:m/ b6nis

  Consider a particle movwrw5 c2dqcou-): o-lqing with constant speed such that its acceleration of constant magnitude is always perpendi2qc5uwod -r :c)qw- locular to its velocity.

  What type of acceleration does an r( cht96 / lz(zwhf1dyvm nn:1object moving with constant speed in a circular path ehl 1zfhznv9wy/ 1d(t:6rcm (nxperience?

  What force is needed to make an o65q sn q2 vrvstqqm5+3bject move in a circle?

  When an object experiences uniform circular motion, the direction of o4b p71klqed/ the net forlbq4e/ p7dk1oce is

  A roller coaster car is on0mm s1p-pinv+ 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 for its centripetal ac p0sv-ni p+mm1celeration at this point?

  A roller coaster car (mass = M) is on a track that forms wworz :rh7o7m.ze 13,ayqn.ta circular loop (radius = r) in the vertical plane. If the car is to just maintain contact 3t1o rh7z.eyoa.mz:w 7,nwrqwith the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertpznw78pmgj4 t 8w y51wical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest p 8 4wpjw17ny tmwp5g8zoint, 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 , zqvmw q f.x)wx2;n)eikmb o3hg:29jcurve 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 xtf.,q0jktd-u c+u*l1 ih(bl a constant 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 tkxl*,t1tj lb -q+i f(0d.h cuuime, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Th0n g60l/wocpdjz8;ny en it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, n /pc8w0gnd 0jzl y;o6compared to the first?

  A car of mass m goes around a banked curve of radius r wipo(v k(*p:u q6rkg+ pdth speed v. If the road is frictiongko( u +*vprp(:pkq d6less 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 banked at the same angle, but one h ;c06/zjrqfuf d78jg c/7nk xuas twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the safe speed on the larger radius cuku fz7cc j 7ju;xdg8/6frqn0/rve?

  The banking angle in a turn on the Olympic bobsled track is7e kpur4,v;c6 o **iq1snvxpx not constant, but increases upward from the horizontal. Coming around 4;1p*i* c6eunpx qvxk,o7v rs 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 aro7wsboynz.j1iwld(k 0m* 1qp:evxl *)und a circular path to have both centripetal and tangentiaklwps*j ()qxow nzy7d10e*i1:. lm bvl acceleration?

  The gravitational force between two objects is proportionkcg 4nm oai3u* qv(s5u0sfujbe*+3t 5al to

  The gravitational force betwhctop8f27 7)dm lvx y,een two objects is inversely proportional to

  Two objects attract each other gravitationally. If the di3n41ygud l q00yqp 1zdstance between their centers is cut in hgdpq0 y1q4n1l 0uyz3dalf, the gravitational force

  Two objects, with massq6157r(b(uzoyqgzn u5r; ek x es $m_{1}$ 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 massesi7ft3a-yx0fgqp+t x) $m_{1}$ 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 univ7j*u 5l wyl2q*(+)me m5e,ycszq oljfersal gravitation.

  Compared to its mass on the Eartd; qeeif;cc1 :h, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it 0 6p;1rqbr (dtkg*8af rcu+p fis on Earth. An ob0+6 t fg; rac 1dfrr*qkpp8(ubject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, th0/z tm s)us ,5w5insvce rocket's weight

  A spaceship is traveling to the Moon. At what point q -7oeq*2yjy1hf kktj gb54g2nja 9h- is it beyond the pull of Earthhybkjhe4 j-q1- 9 jg *5227fnayktoqg's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Whh v5/dco0 aw1pat is its centri5p o1a hwc0dv/petal acceleration?

  A hypothetical planet has a m+wbr.laj), qk ass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravia,+j)r.lbwq kty on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is o.s kr r xbhy ig:8b60q0ic8nboeg6x04ne-sixth what it is on Earth. The radius of the Moob:68gb0gi s.b8xhynk6 rriqo4xc0e 0n is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same sur,y -a q(5e5 xcoq1hu gf4rbc.yface gravity, but planet B has twice the radius of planet A. If planet A has mgc b.o-qc, u q(5re1yhyax5 f4ass m, what is the mass of planet B?

  Two planets have the same sar -o9d7ojr e1urface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of plroa- e r9j7d1oanet B?

  Consider a small satellite moving in a66d njntd(0 k zbv 0px-er3v3q circular orbit (radius r) about a spherical planet (mass M). Which expression gives this sa03 v b evtd 3(nzjrqkxpd-06n6tellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same i4pf78weew n*orbit. Compare the two satw ip nef*84we7ellite's speeds.

  A person is standing on a scale in an elevcd9y *dr2+e0.uxaf7jc zg /ak ator accelerating downward. Compare the reading on the scale to the per. zk xcd9ga +/e 7r*2u0cdyajfson's true weight.

  Who was the first person to real(+vyrf+a)kbz0k l0ldg ;w + bvize that the planets move in elliptical paths ar+vy agf) 0++b;vbrlkz0k dlw(ound the Sun?

  The speed of Halley's Comet, while trathfy,c -8va3yveling in its elliptical orbit around the Su83-cat y yv,fhn,

  Let the average orbital radius of a planet be R. og093h bi yfqm0qi9 -hLet the orbital period be T. What quantity is constant for all planets 0qigoqb myhi0 -93fh 9orbiting the Sun?

  A planet is discovered to orbit a x f)zp4us,ex2yaylib7h 55b 9round a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our 9xhx 5s,lb5bz) p27a4ieyyf uSun. If that 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 the Earth to the Sun is defined as one "astrkmbd8 ) e.,fwqi/ qw)honomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average m)kdb/ qhwfe8i.qw ) ,distance from the Sun?

State Kepler's laws.i q -0f,wdpcdmz5x 98z

  List the four fundamenta*ig7r z 0 .8nek1mzokkqr 3(kdl forces in nature.

  An object moves with a constant speed of 30 m/s p asbfk6wv0( 4/oqnk) on a circular track of radius 150 m. What i(aw q/skb0p4o)nkv 6fs the acceleration of the object?

  The maximum speed around a lnyj1-scga2e3 evel curve is 30.0 km/h. What is the maximum speed around a c1jae 3nycsg2- urve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleracr9h-dvogs9hx84( hwi ;r zb.tion of a point on the perimeter of a bicycle wh -dh94r 8x9 bv(rh.owz;hc igseel 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 from the axicmnt2bs7 m:.x; nm0 wfs. What is the cennb; c.0sm2wm fmtn:7xtripetal acceleration?

  How many revolutions per minute must a circgtct l h77cg21e+:ukyular, rotating space station of radius 1000 m rotate to produce an artificial grcug ly21c g tkth+:e77avity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 2nr 2df yck5:;o50 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force ; 2yc5kfo rn:don the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-qoy *t l2pd6f,m string. The system is whirled in a horizontal circo6f2d y*, qtplular 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 break?

  A stone, of mass m, is tmqb h9*ig9e/kmp jf**/(lofattached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path tfoe **(gl*fq jimb99t p/ m/hkhe 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 a verticnkepf. n9r - qnm(:gk/o:ayy/al circle of radius r. At the exact botnf:k9:-k/ q yn. ry/manepg (otom 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 accelerati g8ta3od cqqc9w7g/m (kktv2,on of 4g when pulling out of the dive. W/tdc7c2goaq9k w8gqv3 t ,km (hat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical l;fs )i61svu bjoop (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 going 16)u fji;vsbs?

  The maximum force a pilot can stand 78k hyvfqw d5u*r24ke is about seven times his weight. What is the minimum radius of curvature that a jet plar2 y kfw7h4de* qkvu85ne'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 with the tires /2bmc q+x pmh8cfv 7z.on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the sv/h pcm8+m.2f7 xbczqame coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat ckp(; j*fzzuo7b m 8xb2urve of radius 50 m with a speed of 20 m/s. The cenm;xu2(zkb 8 7fbpzj o*tripetal 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. What mk c0y d,:1xeiuust be the minimum coefficient of friction between the tires and the road for the car to make the e,d ck ui1xy:0turn?

  A car is moving with a constant speed v around a level curve. The cz5:ip1hqp5th r bff7h z/ b,9goefficient of fric zz7h 5ph,fbp1t5q9:/ rfgihb tion 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?

  What minimum banking angle is requiredw2+jah4 (rr r(oefhtgac8-b6 for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictrj+htfr-e cobg( 2aa84r w6( hion.)

  A horizontal curve on a bobsled run is b pp9 pix.z0zr-anked 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 fog+xo;bmx7,4om 0 vtm ;v ;of$45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m istbv r pt03r6d5 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 u 2l rxloy 5so;emv,3tk2.e;mxniformly in a horizontal circle2 v y,; .elmmr2 xooe3kxtl5s; of radius 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 rz.s: xk *4)k i6m3llarcq :izface car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of :a*z4)3l.k :iks irfxqcm6l zradius 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 consis: 66dmdyhk( .vwrf1 trts 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 standing on the Earth, due to es4x,nu1xrk6 iu * i5 g1rtt/hytr7/fthe Mookriyixn u1t*u g1x/f4 r5,rtet/hs67 n? 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 forcmdkt76t l8 t 1fi0ycy9e between two masses is F. If the masses are moved to half of their initial distance, what is th7f yt1yl mi0k6tc 9dt8e gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from t )3;dawecyqi; m1f3 jjhe Earth will the gravitational forces due to the Sun and thwm fadec i3;;1yjq)j3 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 Moon i:1+y vpi /)qzpdb o8jrs $7.4 \times 10^{22} \; kg$ 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 E+w3 tbb*x try*arth equal to the radius of the Earth. What is r**tyb t xw+3bher acceleration due to gravity?

  The radius of the Earth is R. At what distance above the xbup;7nz 9-r+an* 24frftg wgEarth's surface will the accelerationw fpxb+an9t u2r z47gf g;*-rn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Marsbms05uk ffl5: 0qdjb 4 at a distance above its surface equal to 3 times the radius of Mad ubf5lj4b0msq5f k 0:rs. The acceleration of gravity 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 acceleha/khbrv*t(- .r s)hlration of gravity is h *hshv/k)r- btla(r.$32 \; m/s^2$. 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 b. y q)*e2nud; i.laemhas radius r. If the object is raised toi2 .nq.am;e* dbeuy)l a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weigy x o2mfx,b ok*w:r+i1ht of a 100-kg person change when he goes from sea level to an altioo+xbx, f wi*:m 12kyrtude 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 dn68 7vw.,cb iexw ,ke3r above the Earth's vxwieb 7kcwe8,n6 ,.d surface. What is the satellite's weight?

  A spherically symmetric planet has fourar066d4k /8pygz rvjt9:z+xwkyn 9d w 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 surface of this planet?9/pr9a zt6w wy86y4jr:zvn+ d0x g kkd

  During a lunar eclipse, the Moon, Earth, x8e2xg3tlxm:p;puqa4;m y+8 onxvyn3r/en / and Sun all lie on the same line, with the Earth between the Moon and thy2q 4tm8 xo/ nm uy;+x: 8g3p3ernl avpnexx;/e 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 transported to the Moon. o8q369db9qxf/ kh 0k-teczwi
(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 circuo4-6:kn3h-u lciysulg:n t n6 lar orbit about the Earth (i.e., it just skims the surcln 3lthu-o: :u ysn4kng66-iface of the Earth). 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 low circular orbit about the Earth (i.e., it jussr )mz,uz ,d.x+1ye cbt skims the surface of the Earth). How long does it tabcsdym,re zx,).1uz + ke 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 :h p7z)t3zlfx of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth ist7h)z zp3lfx : $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital d )wft9;ehf v,uiameter 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 rafk2 js14wn(sugixp -2yh 9pl/dius 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 radiuwfq2 c 7mfqo 86ipr9j8kjr(i/s r, qcpi88jo/(w27 6 rjrffmki 9qand moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isq6 ukmjs-j ,r, $7.78 \times 10^{11} \; m$ 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 we p960yanqmzr- -c/7su bdue.r(p b,to orbit the Sun once. What is the average distacyuen wr/p6(,p es -7bqrb9z.a-ud0mnce from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)