Is it possible for an object moving with a constant speed to accelerate? Ea ovhir . ip+id6 xh8fspv0h;2tr z9-/xplai;9 h0 ihfavrs/8ixrz vh t2 .d-pp6i+on.

  Consider a particle moving withdc kp iaz-*)lof-ag5, constant speed such that its acceleration of constant magnitude is always perpendicul dlaz g-op*)af,kci5-ar to its velocity.

  An object moves in a circular path at a constant speed. Compare the dit5 y(sly(wp)erection of the object's velocity and accel( pys( tley5)weration vectors.

  When an object experien8fm uqji ;01pqd1cwy1ces uniform circular motion, the direction of the acceleratifqu;iqw m c8p111d0yjon is

  Consider a particle moving with constant speed such that its acc; r2;he)vm rcc w:1juij(eh3eeleration of constant magnitude is always perpendicular to its ve3 v)e ewrhr 1(hm2ujeicj ;c:;locity.

  What type of acceleration does an object moving w n)mgetnf7tf175mrpg4ynb x lw+ 9b 85ith constant speed in a circularfexplt4)yb8gb +5951rfnwn n 7 g m7tm path experience?

  What force is needed to mak :hh+n ev+8*okz:mcry :frru9 f/q 3hge an object move in a circle?

  When an object experiences uniform circular motion, the direction of the net kxm iv4s2ofcbop e6vg:( 7gs5/(lxk6 force ixo:ixksv6 fglbmo 64 /e5 (72 c(gpkvss

  A roller coaster car is on a track that forms a hyev g12hi;gshta2/ ) circular loop in the vertical plane. If the car is to just maintain contact wi s1yg)e;2ghahvih2/tth track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (massfy2y4kiv c0i:-k vgp+ = M) is on a track that forms a circular loop (radius = r) in the vpv+-vi04: kcyky fgi2 ertical plane. If the car 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 a semi-circular rydk;ecv r0bn-. b) .hp vf7(rarc until it is going straight up. Just as the plane is at its lowest point, the n.b-. 70rpvrfb ;h)(vyre c dkforce 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 radiusz:rp nb,9nf ,b $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius rp5z sh.:4 eguh at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on up gh:5sze4. hthe car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radi bx2xvyjev sc uh x hu2-70nh75 4./ukwpc7e0pus r at a constant speed v. Then it goes around a curve onh5h-jchpwbxs 27ue4xp27.e u/ y0u v7c 0xkvf 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 a banked curve of radctupp9 g2) c)qius r with speed v. If the road is frictionless due to ice, the car can still negotiatpccqt9u2g) )p e 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 auo8 wm4d1ee p6 bobsled run are banked at the same angle, but one has twice the radius of the other. The 8pm 1e6duo4we 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 curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, +m 6ecg1z1qci 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 t i1e q1z+ccgm6his?

  Is it possible for an object moving around a circular path to have botho;wxlp0(7ptvzz,y1 x x2.il x centripetal and xpz1v0lo;xlt wx yz2i,x .p7 (tangential acceleration?

  The gravitational force betw0kvwz3a k3 wm2een two objects is proportional to

  The gravitational force between two objectsshp/v 5q*rqeag;as9 5 is inversely proportional to

  Two objects attract each other gravitationally. If the distanch z yx+h;ul9w*v1u c6+/h (eevv vhmj.e between their centers is cut in half, the gr9h+ uv6.lx;z1/c uh+hm vv eh(*e wjvyavitational force

  Two objects, with mas dr8 x6xd1ey r/iwnxaie8( 0ey+d3za8ses $m_{1}$ 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 ma iov/yk:lzo .ur a4*0usses $m_{1}$ 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 gravitati8w; clt)h6yn eon.

  Compared to its mass on the Eartefcj4 3u5cnd3r 9d6cl h, the mass of an object on the Moon is

  The acceleration of gw4c(;b/ qbgedlmh1 m72oe q4eravity on the Moon is one-sixth what it is on Earth. An object of mamd;beo47eh14m q( blc 2ge/qwss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, th 4p.m)0ekvng be rocket's weight

  A spaceship is traveling to +ob2 2nft ,w9qg 7ycfathe Moon. At what point is it beyond the pull of Eart2qngot27bc y9,+f aw fh's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. What is ay:o /xb/nb 1bam zfw10,ua1e its w axfzybb/ e 10 m:/o,uan11abcentripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of g64dvka a l83itwice that of the Earth. What is the accelerat6v3alk da4 ig8ion due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on tp-.iw0mi .)nc, wasx1j*s5wln8 v mpihe Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass c.mcjpx0 i nlw1iv85,ss m* iwaw.)-n pompared to the Earth's?

  Two planets have the same surface gravswu*bd o t;c9 ;,fnja.ity, but planet B has twice the radius of planet A. If pl;t;.w jas9nd,ouc b f*anet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B ha:txj1 :fz hatom p-/k/s twice the mass of planet A. If planet A has/kxot ta:/ j1pmfzh-: radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheribt0stj nz-w4 -cal planet (mass M). Which exn0tsb-tw4 -j zpression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the say 30 vc u.r1-tbkkjb+tme orbit. Compare the two satellite's spee u -t3b1tjck.v0+ kybrds.

  A person is standing on a scale in an elevator accelerating downward. Compar5cetux 0 5evk4 u1em4xe the reading on the scale to th15ceeuktv0u m x445xe e person's true weight.

  Who was the first person to realize that the planets move in rbg9c5v ,m(fwelliptical paths around thbc 9v5mgw f,r(e Sun?

  The speed of Halley's Comet, while traveling in its elliptix)oe h3-7 5*xlgwydma tlc0-oc1.mimcal orbit around the S 7lwoxcy )mdhc30*i.1mx l--m5gat eoun,

  Let the average orbital radius olc 5nr w pvwjej1a)j.r;,h*m:l +tq;qf a planet be R. Let the orbital period be T. What quantity is constant for all 1wjq; vam tq.j n*lwh +r;jlr5 :e,)cpplanets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with ni eafq2b4 js-wed fmvht7+* wj(/(3dthe same orbital diameter as the Earth around our Sun. If -ew d 3nh7qfma/(+j vj2(dfbw*e its4 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 defi8xe +par+ r mefy o,00g 0jquc/83abskned as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third o08+f0q/j8 k + 3srxpe , ageyburmc0aof a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.a qir9i*/31lkgvlw h c4i-y2y

  List the four fundamen st(ytl .mtz4u jtem.wf y4p-50dmm4 *tal forces in nature.

  An object moves with a constant speed of 30 nc973d:lu ;foo5 ifcbm/s on a circular track of radius 150 m. What is the ac don loi9bcf:u53c;7fceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum speed:ou//yc m o.f1x c5wap around a curve with xm.fwopc ya15cu o /:/twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of hfmc5 r32 /v sx-fpp5da point on the perimeter of a bicycle wheel of diameter 70 cm wh/s5xhm 3-pvr2c d5fpf en the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.0t7hkaa2hza .p /l-y+h0 rev/s is located 0.200 m from the axis. What is the centripetal achz y.a ap+k/tl2ah7 h-celeration?

  How many revolutions per minute must a circular, rotating space statigff/f55n sfx t 4o/8ozon of radius 1000 m rotate to producef 4/ /s xnf8tgff55zoo an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around ,e)-7qxyfbll a 13.7 m radius turn at 96.5 km/h. Wh7-lfbelqyx ,) at 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 xi,6zf)v4x9o lsw +9j7fuwg d is whirled in a horizont x,f4)f wwiv j9oxslu+dg6z79 al 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 break?

  A stone, of mass m, is attached to a strong string and whirlewymd. oo.70 fqd in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the sf w.m yood7q.0tone's weight. The stone's speed at this point is given by

  A stone, of mass m, is at)lx4 n3tfad8 ctached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the dt)xnla 43c f8stone'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 oucd3.cg9e11c gd)f nmz m e9ny;o;vc7xt of the dive. What is the radius of curvature of ;n cz3de79ce nmy1c;g mgdf1vo9. cx)the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of 3hfa hrqw9)fd+3rf)s2 jr4yqrbgu ,2the loop is beneath him) of radius 3200 m. At the top of his loop he is pu4shrrufjw qayd,+93b g2 )rhff3 2)q rshing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a bya8m6 - -y)z+*xed.+brmbtun 2idwlpilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of bb l* itx -+yn.+2 mbrm6)-wdey8dzua a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius hoz nz/.: fs9s6, hzeomnrizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume then :nzsh6.z9,/emfos z same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 h zyz*k wjrj .3zv-.2zm with a speed of 20 m/s. The centrip 3yjh z.*-rvzzj2 wk.zetal 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. Whatx /bqd k+oh2z54fd. kt must be the minimum coefficient of friction between b5qh/k 2ddx. zt ok+4fthe tires and the road for the car to make the turn?

  A car is moving with a constant speed v a;-pc kxpgi vq(1dpj. 8round a level curve. The coefficient of friction between the tires and t x c(ipv8ppg1k-.djq ;he 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 bobslez0bccv05;aib(oc c4k d to negotiate a 100-m radius turn at 35 m/s without skiddingo 5zc4; a(0c 0ckcibvb? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at hk5br *nqc1(x) t5urta $45^{\circ}$ 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 ct+74qa4jezm.k, ecg -6no o uof $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 7(au c/u0xu gr$45^{\circ}$. 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 e/c , 9:en8 op(lfkwfgznd of a string is revolving uniformly in a horizontal circle o8k /ow9gl:fze np, fc(f 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 race car accelerateq+w* bro g bgf1s*+v .h/lyv9zs at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in tfqg*r 9l+*b +ozbsv.1y/g hwvhe 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,shkmrr2xcmnd ,e(.- tz-/ cg 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 o; w mtdi0y b.kzm99w1an a 70-kg person standing on the Earth, due to the Moowd0y w mk 9;.9mazb1itn? 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 massnuuom8cdo1 p n ifhz)c(9 ,-5les are movu-,no1 zl(c iho9 5pu8cdn)m fed to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at whazrgby:0sm .4rad -lw.t distance from the Earth will the gravitational forces due td4 ag0b:sw-rmrlz..yo 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 i h s*.(dvew wylbsg7:f)6(lcgs $7.4 \times 10^{22} \; kg$ 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 vea krr0x(vcq2)jfkr.w5v/ 0arth equal to the radius of the Earth. What is her accelerationvr fc)j2r/xkve.5(k qar 0 wv0 due to gravity?

  The radius of the Earth in o3*a3u+elvy9t+ar gy v0q0bs R. At what distance above the Earth's surface will the acceleratiou lqoy+r en0 +ba*g0tvv 3ya93n of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal :aqe 3u*x0nm. pg) irbto 3 times the radius of Mars. The acceleration of gravity of ther.3 e xa0pb*qium:ng) 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 acceleration of granr ,/b1, l,w oamhewop/nn(e 7cs.; p qqql,j2vityle1a,ps n /w nn 2h/ e,p7qlb.jo(wq; ,qo,crm 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 Earths4 8k0m0o aobs0mnc e0pb4k 2zpo;ps- has radius r. If the object is raised to a height of 3r above the Ea0ms-44sck0e ps0npoo 0p;m 8 obabkz2rth's surface, what is its weight?

  By how many newtons does the weight of a 1jakikw.bw82 ud25 ww,00-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of.2w,2j bu5 kiwa 8dwwk the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellit)f7h2i mw/2kttqk4lze of mass 100 kg is at a point 3r above the Earth's surface. What is t2/tz kfhk2l7)itm 4qwhe satellite's weight?

  A spherically symmetric planet has four times the Earth's mass au 6**r)8aazcwh *nz jond twice its radius. If a jar of peanu* * wzh ca)jo*6an8zurt 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 zzzj,u p3 yj nu+:7,1idn vnz/all lie on the same line, with the Earth between the Moon and the Sun. The Moon , : 7 y,z1jiu zzpn+nnj3zud/vhas 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 n+xqd84lz9 - d5v3vcjhc s;r aMoon.
(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 Earthiw7*x f sajsp8sx,.+ gy0o ig) (i.e., it just skims the surface of the Earth). What is the speed of70)f s gs,xyi*+ xwg8osj.p ai 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 just ski;9bu(1t bh dftms the surface of the Earth). How long does it take to make one revolution around the Earthdf1ub9t; t( bh? (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 wxcwz: j-zu,b - x5n9mmhp- d3is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Eah5 mmpd39-zxu:w,-z-nbw x jcrth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of pkqqq:lb, od58i 6 5bw$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet withr*)tb brx w32k 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.p98d7w x0dhpf Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to comple7whd 98p f0xdpte one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ism72tj qtb lu9) $7.78 \times 10^{11} \; m$ 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 th2wn 4myhc6at 3e Sun once. What is the average distance from Jupiter to the Sun? (T634ch2w anym the distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)