Is it possible for an object moving with c emhuf7tn33ho) u: a,a constant speed to accelerate? Explaionh3h uam 3f7)e,:cut n.

  Consider a particle moviulm7 aoie) d(s0 n9w(fng with constant speed such that its acceleration of constant magnitude is always perpendicular to () ei07wm lau9 o(nsfdits velocity.

  An object moves in a circular path at a constant spx+z:wfatk.lnf3z/-ttu 0l0i eed. Compare the direction of the oz:xtft z -wftl0a/i0+.k u3nlbject's velocity and acceleration vectors.

  When an object experiences uniform circular m 3a u1jx2;, .lo5mpf /qdwfxnvotion, the direction of the acceleratdf3n j q.l,/p 5vx;ma ow12fxuion is

  Consider a particle moving with constant speed n )hx:+ lwi8 d8jfkku18n4f dradm7m( such that its acceleration of constant mn()drl dk8+nkd1f m a8hwx:f i4m7uj8agnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with co( xkpn 0qci37hdmr 1)uum: .itnstant speed in a circular path experience? kh71ri3ixpcn(mq: .)du um t0

  What force is needed to make an object move gr2,hh7+d jyxs k)nr1in a circle?

  When an object experiences uniform circular motion, the direction of rg*meu+ +/ bfythe net force i*/+ury+emf gb s

  A roller coaster car is on a track that forms a circular loop in the; dtz-fx h8qd9 gd4o0a vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum val8q dx-aof49dh g0;tzdue for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that formsz6sunm , ta s.vfp1544ryn bz,gu9od3 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,omub5nz,zg94 n.uyd vs1,frt 3 6as4 p what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then fpn0hf)(+udcl nh r7b7 ollows a semi-circular arc until it is going straight up. Just as the plane is at its lowd(c)7+ 0unn7phlrbfh est point, 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 curve of radv2(vfy o+nyh( ius $r$ 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. te;9tb7 sdy 4vThen it goes around the same curve at half of the original speed. What is the cty ;ed4 vbs97tentripetal 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 y*k5m:iob zy -v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car 5o-: *y zbkiymas it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radiu9sqy,5n y8mpgs r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the mn,8s5yygp9q horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on acux vxv w r;e,e; u*ih+aq9l2, bobsled run are banked at the same angle, but one has 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 thv* ve h2e,+r ;xc9wixuua ,lq;e safe speed on the larger radius curve?

  The banking angle in a turn on the qb; 7ge:rbcxzbr:7 l5Olympic bobsled track is not constant, but increases upward from the horizontal. Coming arcbxb77eqrb:5 rzl; g: ound 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 around 30twyo)s5 plra circular path to have both centripetal and taos0p5r3wt )lyngential acceleration?

  The gravitational force be5uvgvqzb; i:w bt8 6*dh+ zr3lp7ol)rtween two objects is proportional to

  The gravitational forc 7z)zy:rhj : zjw2j(er+r8qade between two objects is inversely proportional to

  Two objects attract erfhktzq9s (865q (meyach other gravitationally. If the distance between their ce5 h tem 9qq6r8fyzks((nters is cut in half, the gravitational force

  Two objects, with massi v9h5 3j49niuhc( wnses $m_{1}$ 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 maxztm d5mmdu .+ry i**+sses $m_{1}$ 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 univers/ xdf cy+rz*d5ks,r 0yf8* xpsal gravitation.

  Compared to its mass on the Earth, the mass of an object on the (am,pk 2m3 c9z, rp//o kbuvirMoon is

  The acceleration of gravity on the Moon is one-sixt,dte 6zp): n 6)l gjxyyb7wkdyu,12 yfh what it is on Earth. An object of mayz1ky)fld2un t e ygwb7y 66p,):xj d,ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfq-x jb n;7w d/p)jih,face, the rocket's weight

  A spaceship is traveling to the Moon. +1sph fnt a351fh0jxkAt what point is it beyond the pull of Earth's grtkpn 1s+ 3f1hj5ahf 0xavity?

  Suppose a satellite were orbiting 0u gh7)vc+f bdthe Earth just above the surface. What is its ceu7+ fvcd0)hgbntripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of ryuuip; i6ee 52be/ a9 j(abk.twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the accele(apb er65 b9uiiy.e j2a/k;ueration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth w g/mq/f4wf c,fwci au55:p-pdhat it is on Earth. The radius of pf5/: c4pcu g fafq5,m-w /iwdthe Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice t h58 aolt/ch1wk41s mdhe radius of plana511 thds8 kc4h/mlowet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet9z -sw r+bwy7k B has twice the mass of planet A. If planet A ha+zk 9sbyrw -7ws radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius rz;c*q0 .sbg93y ukcnhe43vfo) about a spherical planety u 4obc9ec0;f3knh*svqz.3 g (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the sam 9u+n9rhz6m3o msztp.e orbit. Compare the two satellite's speeds .h9ropz+nz9mtmus 3 6.

  A person is standing on a scale in an elevator accelerating downward. Comym+ )glktzb4h79kbg. pare the readin9 b+gkhlb.4tm ykzg )7g on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elxd. wb8) eh *ctmjqg59liptical paths arounqt gxj8.w*5b ech9m )dd the Sun?

  The speed of Halley's Comet, while traveling in its ellipticatsa/98 fa 7nvbl orbit around the Su af78/natsvb 9n,

  Let the average orbital radius of a planet 91kv p /(;vkde(w :p9pwwd cfwbe R. Let the orbital period be T. What quantity is constant for all planets orc(9w e(kp1v:dwp9pk /v;w d fwbiting the Sun?

  A planet is discovered to4imgd,9i *yh 4 v 9abgr3znz/j orbit 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 be, compared to the Earth's orbital pim34drg9ihvnz/g jz *y, a4b9eriod?

  The average distance fa h , :gs)//+oi rp)vrufv-btirom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroidhvg- , )/ +r/)tu ibao:sfipvr orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.vesu/hn (s,: ptt5:: qbgdt.c

  List the four fundamental forc ajz,c ,n:wlp9t2;j2xivl: f (z,wqrles in nature.

  An object moves with a constant speed of 30 m/s on a circu/o0vtw: ry8ab lar track of radius 150 m. What is the accelewtor/8b 0 vay:ration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the m7j/apom u58h maximum speed around a5uo7 aj mhp/8m curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal accele r;f(yiu 7j*7/ oafcbmration of a point on the perimeter of a bicycle wheel of diameter 70 cm when tfj*o bm7a/frc (u;i7yhe 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 axis. Wb+o0a,6c; e;ii bse sxhat,bs s +;oieeb ;0cia6x is the centripetal acceleration?

  How many revolutions per minute must a circular, rotab2zpts 31g /fating space station of radius 1000 m rotate to produce a g32/bft1 zpasn artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a masstp+72wq yhrt3 of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the mo 3p2h rtt+wqy7torcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m str gzz78shi vs6e0-kzwhu 4q gq 0;9kta;ing. 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 swzzitkg8;avh9g;q 0qk- 0 e s476s hzupeed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whir54co-k x jgu:ye o;ja:led in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 timeoujj4yack: x-o:5; eg s 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 verti*c96ep-m 15nv-hjco m inb0ng cal circle of0oi6 *e - c-m1vnhjp9mcng5n b radius r. At the exact bottom 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 acceleration of 4g when p3+jpxe7f p65yrsnvh c.9m q( oulling out of the dive. Wh(9e3rsy +vfp . 6p7hcoj q5xnmat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loh*j*pe,borpg4h y)-/z yrv.gpyxb2 * op (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 wei-g*pveb/gyzo hb.,jp2 p h4 y)r*y rx*ght. How fast is he going?

  The maximum force a pilot can stand is about s w5 evt25sf/mheven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pu s 2fvhe5mw/t5lling 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 .d5onp yxm7q42ltwh 9curve with the tires on the verge of slipping. How fast can this car round a second curv .d2w 5qm9y xt4ophl7ne 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 vp mejfy1a9.(a speed of 20 m/s. The centripetal formfj y.a9(1 evpce provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a f,;2jejcsprb w mkukj))0l/ 6z2g 2zsc lat curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of frictsskc/ e)mkc 20z2 r,2 )6;jguwbzp jljion between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a l*yj2h v9 uc(o0 ( fh7htd4qrgx6kh/fwevel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on th cghu6dy qt2f hok7 h90(x4(rjvfw /h*e road?

  What minimum banking angle is required for an Olympic9fb ; s rbonqx2o;x73p bobsled to negotiate a 100-m radius turn at 35 m/s without skiddo2n ox;sxf 9;3bb7 qrping? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at:tj minjubtn: n (gn8o8+e3.n 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 anne1*5* j+69r;ojgup1cz i b ry dcvv8u angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80,z(kub9q,9x 5zqn ccp m is 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 horizo g+h8 gut(a.(fs4kxlwntal circle of ra(lu(hsfa4 tw x+8g.kg dius 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 arogbsz- u+4 7. gly0wwiea, a race car accelerates at a uniform rate to a speedb.zwu7l4ogigw y-+ 0s of 45 m/s in 15 s, moving on a circular 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 wiu-r7gcs3bl* dj)02 dj 8 mb6ka:bfq$1.67 \times 10^{-27} \; kg$ 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/jowa.j *kucu5t b8l 4 uzu*/r on a 70-kg person standing on the Earth, due to the Moon? The mass of the wt /urab*u*lu/5 8 jkzo cj.4uMoon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force betl8 8yj *s-6e k uy* wmub+ew-ody(z*kjween two masses is F. If the masses are moved to half of their initial distance, what i 8ykwejwbzksu*uj8(-+yl e*-mdyo6* s the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what dhahr 3p) 81/i7engmkvistance from the Earth will the gravitata1 pem hr8 gi3/v7kh)nional 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 Moons-2d7c*wnwlpko s-w,r/i / lwee7)bq 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-wae7 mm7wgn a1+)q-d9cc h koow*lk" at a distance above the Earth equal to the radius of the Earth. Whatgmw hqena*oo)9ck- c1+7 wd7m is her acceleration due to gravity?

  The radius of the Earth yi * j)r cvg3 +p7whqz8za(7yois R. At what distance above the Earth's surface will the accecov(zp)y +8z 3war7 i7hj*yg qleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at j g wst7b gn39 jbt efa:-.1di7nl;5xda distance above its surface equal to 3 times the radius of Mars. The acceleration tl1 7bwebitgg; n -xd5sf.9dj n 7j3:aof gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 140)cyf o go7q-c0ayx.th:te8 +e00 km from some planet's center, the acceleration of gravity o 8et7fyx.o 0+ ahyctcg-qe ):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 Earth has rad3.zxnyv97 ndyius r. If the object is raised to a height of 3r above the Ear39vdz.xn ny7 yth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes frol y0p6nc8x )/lsnfiz,m sea level to an altitudep/nzls8 yfn 6c0i,)lx 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 as45ozljna hloh / n/6.v7/ec pt a point 3r above the Earth's surface. What is the sate oh7vj cpzloa/.l4n5se/h /6 nllite's weight?

  A spherically symmetric planet has four times the Earthychsfal6 3 h: o-qfvcy o9+k4.o3nc 7w'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 .7 f owlh43-:oo fnyqc+svcahc396ky the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Su)bwvo iqzw6na/*jv*2z; d8cwxo49ls n all lie on the same line, with the Earth between the Moon and the S9w)4wsovd 6zn;a8/ oivwxz *qc* l2jbun. 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 transpo;;6fq pxnk v6 o2z1krdah1v4xrted to 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 qxi 8 m7qbmq1-skims the surface of the Earth). What is the speed of the satellite? (Txm qqiq81m7b-he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit abouth 0) z;ii /j(y(pa1 0iv.3-qiomulocity6ivm the Earth (i.e., it just skims the surface of the Earth). How long does it take to makeohmuv0i;iiy)ij ai m1(/z.p (6 o3ytcq-il0v 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 6clvl syx//mc;78d cf/g i)lbthe surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Ecml//xb/ gsl;d8 iyvl6)c7 fc arth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter or zk,5 iwfooh.u; .c5if $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a radius oyyg+a)m *c h,o79 kvdhf $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in ned .ewgtn7 ns qwkzy 7-,ag/:)darly circular orbits. Moon A has orbital radius r, and moon B has ornkgtq)-:,s w ./7dw7yg adz nebital 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 is54rep vj / 3lf5pbc+fm $7.78 \times 10^{11} \; m$ 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 Sujt-5r lew)xm(zw;()r wns; c in once. What is the average distance from Jupiter to the Sun? (The distance from the Earth toct)-(z5 exws( m;wr )n; wjril the Sun is $1.5 \times 10^{11} \; m$.)