Is it possible for an ob. lj /ik;j0hy8tjktf;ject moving with a constant speed to accelerate? Explainfl/k0;y jj.;tj8thik .

  Consider a particle moving with constant speed such that its ac*yys wqr ,kk(2xqh35 lf;fy *kceleration of constant magnitude is always perpendicul yqfl* k5y h3,k;kfsqr2w*y(x ar to its velocity.

  An object moves in a circular path at a constab+.apeiw8q:w nt speed. Compare the direction of the object's velocity and acceleration vect pei8aww.b+:qors.

  When an object experiences uniform circular moti2h1p/5gb chub on, the direction of the accelerh/c b2hu5bp g1ation is

  Consider a particle moving with constant speed su,o (gxhs07w pbch that its acceleration of constant magnitude is alwa07ps, o(g bwxhys perpendicular to its velocity.

  What type of acceleration does an object m a*kmnxe/q ;l( 7*bzd /x,xiiroving with constant speed in a circular patm /*ax 7(,kqdzxri/b ;xniel* h experience?

  What force is needed to make an objeyae*w5e47(x f/wt k d8aarn.y ct move in a circle?

  When an object experiences uniform circular motion, the direction of the net fo(gvws slxn91tk :2yly) dbg: *7opp 9grg9blkdvs:l )x1 n s gy(pp*tw2oy:79gce is

  A roller coaster car is on a track that forms a circular loop in theud7l i2y 8oyg pug0).9c+ucs i 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 acceleration at this p2c dyo . +)9iggs7l80pyuciuuoint?

  A roller coaster car (mass = M) is on a track that forms a cipdug* ;m.g/bx bo*pl98j/vv ircular loop (radius = r) in the vertical plane. If the car is to j .x 9/pm;gb/ v*8givd*poulbj ust 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-circula r5m jzyb4ht8 rnek1ll jt8x+ 1*5(vgwr arc until it is going straight up. Just as the plane is at its lowest point, the flm 1n8j ezbhtwv r5ly*1t4g+k8(x jr5orce 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 radiw.5cz qm pt :58* ef*h3v6 pqneh0bigwus $r$ 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 v. Then )m b2mbx6v(*k 1yibhant(l)c it goes around thekhb2v)a byml tc1)*im(b6 xn( 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 the first time?

  A car goes around a curve of radius r at a h/.ja zu*:1n(owqsj(xpk g: d constant speed v. Then 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/sjn1gw(:(hjkqa :u opdx.z* , compared to the first?

  A car of mass m goes around a bank3av5f)ml b4 *bh2i )jj bo,dzeed curve of radius r with speed v. If the road is frictionless djdbae4i fov*z l5j,32)bbm)hue 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 cdb5pe2/3i(c ub c(q(dzu6i3 qe)fyn are banked at the same angle, but one has twice the radi/ 5bp 3cnbzf u(6icc)y3qeq ed (iud(2us 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 curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, but inqd(0owxcn 8 j7creases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wal7nqc x j0wd(o8l," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving arf- xjey(u )2w3nb-d-ul0 c pvlound a circular path to have both centripetal and tangential acceleratio)y0-l puxv3 cdf uj-e(2l -bnwn?

  The gravitational force z+:)u31w1mqu7 kk:ec g qjukqbetween two objects is proportional to

  The gravitational force between two objects is inversely proportionauqg2 5y:g+ l9h0drzb5 uh;vmtl to

  Two objects attract each other gr *h55q/y bio5dh tnkb6ktf 1e 0-(datiavitationally. If the distance between their centers is cut in half, the gravitational forc6kbh( 55 /y*a iodikhtd t5f1q-0tebne

  Two objects, with masm d8c-of c,ia6ses $m_{1}$ 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 y+4k/ewhz9 o kki50;t5hrr qu$m_{1}$ 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 gravitationb 6yhv 2rh;6fr.

  Compared to its mass on the Earth, the masvyb:te * +vhy4s of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An ob bxj)k//:augu. q f0vhject o/xfb:0v)u ag u .qj/khf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rockelr jrw02i zd oxa:l:,-n vz5*j6x2km efvm4-it's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull o*ri0a;rek;2hq8 g qnuf Earth's g*uq ke2 hqi80ngar;r; ravity?

  Suppose a satellite web okjf-/tx+mm41 fol5( mzju2re orbiting the Earth just above the surface. What is its centri/ lfm-1(t ofjomz4mx25u + bkjpetal acceleration?

  A hypothetical planet has a mass of half that of 9n atz fl:hytr4,28y*dto /qx h5nj1cthe Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in termhyd4q t9,a tr2 y*n/x5hltjz1fco:n8 s of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth.r scuyzpgf38h j-/ld*vwz(oj f: 5k80 The radius of the Moon is one-fourth that ofzk d0o5 vpw8cjl grj*(8:u-3y f /zsfh the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but.eid6jnl t d-x5wjo(c)ea 1 1v planet B has twice the radius of planet A. If planet A has mass m, what is thvcex5 dld(6.j1e- i 1njwto )ae mass of planet B?

  Two planets have the same surface ghme;bko ; l,:jravity, but planet B has twice the mass of planet A. If planet A ejkb; :ho,l;mhas radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abou alo kdpo,v;(: xa6,i-lop/vst a spherical planet (mass Mavpao(, kx 6loi:,ld/o-v s; p). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of samnen7z 5wh0k+ tellite B, and rotates in the same orbit. Compark70 nzn+e5hm we the two satellite's speeds.

  A person is standing on a scale in an el1 w g/6mb xc9aal (dcvi)x)(ytevator accelerating downward. Compare the reading on th)) mtcvxld iac /gxa9wyb6 (1(e scale to the person's true weight.

  Who was the first person to realize that th(2i jxhj3p;opndoy64vp7lr/uv 53v ce planets move in elliptical paths around the Sunxynp4v opo;733vi u2phr5 6(ld jvcj/?

  The speed of Halley's Comet, while traveling in its elliptical orbhs mi(ee:34mxit around the Sue4(i sh:me x3mn,

  Let the average orbital radius of a pdtylq; s;ni1qc g q*7,lanet be R. Let the orbital period be T. What quantity is const*g1d7s;;qqq, icl tyn ant for all planets orbiting the Sun?

  A planet is discovered to orbit around a ,cqm9ad - p 1l(dn in3scyd17vstar in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star li9 dpdn1acnc7(sy1 q3mv-, dhas 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 x: wtr)1 fm0tk/ef; uxto the Sun is defined as one "astronomical unit" (AU). An asteroid fum1 xxtf0e ;)k/: rwtorbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.mvnn y, z,:np.

  List the four fundamental forces in nature.280 fspvr -bg2q3 pos /mvkyt8

  An object moves with a constzhke y /1q(a m3da -je:tu:adlp9q 2,vant speed of 30 m/s on a circular track of radius 150 ty:(ma2hk1,z pd-eje/9a uav :q dq3lm. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 mkeg(.i if yb34x2m /lkm/h. What is the maximum speed around a curve with twice the ra3gme mi/xk.2y l4b(ifdius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicy82e1z(mbna8 9 qp kjt)gtd/pycle wheel of diameter 70 cm when e)8 jg8dybktqn9m/ (1apztp2the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locaa i0o;zit)jg +ted 0.200 m from the axis. What is the centripetal accelia )0oti;+zj geration?

  How many revolutions r3vf c ws f5k0tr9yx82per minute must a circular, rotating space station of radius 1000 m rotate to prxc98vtr3 k f0 w2frsy5oduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 139enwpm;,*i e 6fxbml2.7 m radius turn at 96.5 km/h. eb2f9ep ,; *wni lxm6m What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attachejv) +-i(t jbq68ig kvhd to the end of a 1.0-m string. The system is whirled 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 i8i (kjvi)vgjq 6t- +bhf the string is not to break?

  A stone, of mass m, is attached to a strongh rd*a*hk e(5;9klz2k hw( hdz string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone'kha;kke*hzdlr5( h 2dwz 9(h* s weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong s m4sg8q4)q iegtring and whirled in a vertical circle of radius r. At the exact bottom of the pathg ieqs8g4m )q4 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 acceleefjw)6honl; + 4eeba2 ration of 4g when pulling out of the dive. What is the rad2+bwe afenj;)lh o64 eius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the (t ux)+w7 yte;n2puio ,5vvztloop is beneath him) of radius 3200 m. At n w)ot uiyv,x 2+vtzp(5e;t7u 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 can stand is about seven ti6 xex ryx,zkx)zl0/ s9mes his weight. What is the minimum radius of curvature that a jet plane's pil 6 xxl0/ szr9y)ze,xkxot, 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 tire*0 tf*53x /smszc3vftr* (x:onzrgml s on the verge of slipping.z0(*t xlt*s:xro/ rsfg fm3* mvz35c n 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 radius 50 m with a speed of 20 j5m+ h p r1*7k1cxmo6unr)inlm/s. The centripetal force provided mjr5lmrnox7i1ukc)p 1 n+6*hby 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 (tr lx-y+g7hj m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tire-7 +rgylt jhx(s and the road for the car to make the turn?

  A car is moving with a constant speed v arounm 4nd15 6 hr5iaesh1ved a level curve. The coefficient of friction between tms5aheh 4d5 61v1nerihe 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 requirob,m ft9ieunm+f8m.59 zcmu3ed for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidd.o89n+ bzm mm5t3fi9c fu, umeing? (Ignore friction.)

  A horizontal curve on a bobsled run is banmrj+ r9n(q*wj ,+hr qkkwa 3vlw qj.grr)5.l+ked 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 ra*)luo7eor dfo )3k:rm e, gd.fdius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bank;m mhfzt0)-st ed 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 re4zfa:z din.1sbseq q/3+ 9 vdwvolving uniformly in a horizontal circle of radius 0.500 vqbds4zsqf nz /9a:3i+ed w.1
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 ite/ v,mf viu41/ d9wfms3ul 7on the pit area, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circularul4d37so,iw f/m vu1tefm/9v track of radius 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 consists of a proton of mass yj 7d7yrkyg* u7az sm6634i qp$1.67 \times 10^{-27} \; kg$ 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 onb4v a.)in3abti2 f xvdts0nrz c:- o)7 a 70-kg person standing on the Earth, due to the M)c 3nst -o 7nx)b.if vbzrd40a2itv:aoon? 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 dc; 21ev5vfr syut8+a3u fv-fis F. If the masses are moved to half of their initial distance, what is the gravitationyu13 -avfrvcsf8u 5f tv +;d2eal attractive force?

  For a spacecraft going from the Ea-)qx qmw qt86arth toward the Sun, at what distance from the Earth will the gravitational forces duemq6 q8)tqaxw- 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 ix68+oneb)l dig5zus1.an lo2 3mnn f5s $7.4 \times 10^{22} \; kg$ 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-wh8;r b 4fa2gbd7l2cgoalk" at a distance above the Earth equal to the radius of the Earth. What is her acceleratgghfb;l cao b 722d4r8ion due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfe198vm10,qgq/ bdv d j1bjt tlace will the acceleration of grtqb1 bmd,vt jqv8/d09elj1 g1avity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 no713z *f6pdk hf y;jrtimes the radius of Mars. The accelerati;h7fj1y pzkn3dro6 *fon 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 acceleration of)lmhmq2y2:d 6yg db(jwj4j1 4; oimoz gravity is h dibjo 42q(:yzgmjj)y1 ;m d4lm6w o2$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the sgap3m+cit/1 b 7 vmr m-c0ic3eurface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above t+7e1i-/ v3t a cmgi r0mpb3ccmhe Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goj fygzu9 ;*rou / qansh+4jb;*l. x(nces from sea level tu9xjycs;la +; * rgjzh4(unn.*oqbf/o 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 po p n-3c txez6;6hfs8f.jsir 7xint 3r above the Earth'sr3f6i;z xxe87sfsnt-6 .pjhc surface. What is the satellite's weight?

  A spherically symmetric planet has four ti s llk7zpuwm+dnv;j -knzn *:4k 9.xq.mes the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on szk* mzwj:n.n vd l4 9;qku.pk-7x nl+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 all lie on the : h(mwc i,nv:vsame line, with the Earth between t(:v:i,vwmn chhe Moon and the 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 kzzw4m*8.dwyd 1g*ls 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 abou o6y8lduij/)v t the Earth (i.e., it just skims the surface of the Earth). What is the speed of the sat 6v8ol ydj/iu)ellite? (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 ju vtqrh(: qh 54tc7j4ttor/6w tst skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of th /c(4tqvqr7tw4rt: o ht6hjt 5e Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above t*f u *9dir0ts*7o-act: / chhk3bg hvthe surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius *:t/bat duc0tkrvi7sc-h* 3f * g9hh oof the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, stbk 2j901cls has an orbital 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 orb6vau6k, v1qhev(n(e4z v*hswits 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 hrxjg8f s68mfk1dw7(in nearly circular orbits. Moon A has orbital radius r, and moo7mkdwfg8x 16hf( s8jrn 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 is (baiq v- :zbn4$7.78 \times 10^{11} \; m$ 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 orbitbh15ug s6b)0jt6wr da the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth t u61 dwr6ags)b5bh0j to the Sun is $1.5 \times 10^{11} \; m$.)