Is it possible for an object moving with a constant speep+y9d4qzete ki*-q;g :i:z x fd to accelerate? Explai*z p+;4-xkgz:tii eydfqq:e9n.

  Consider a particle moving with constant spk als2hlozf)2 :o);h /6slodj 0b9bfi eed such that its acceleration of constant magnitude is always p / )sk2 ):0hd92lfsbiajol6blzf;oh oerpendicular to its velocity.

  An object moves in a circular path at a constan7j : bw pjhwl6i7zq9m7t speed. Compare the direction of the object's velocit7z:wbw9jl ph7j q6m7iy and acceleration vectors.

  When an object experiences uniform circular motion, the kljly 6fa):5z+/6h,wbp b 0c6ydriyh direction of the accelerati bfl0/6+j,a dch6y y)k b5 z6rpliw:yhon is

  Consider a particle moving with constant speed such that its e-w.c,mdp(u: ne lrw*t8- cugacceleration of con t (cu d .*wwmne8pulcrg-e-,:stant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object mo(oop qbg8 ;)yzving with constant speed in a circular path eg)opz; bo8qy( xperience?

  What force is needed to make an object move in a c hxs9fs *r jm9/bu-rk9ircle?

  When an object exper8q kwp :b.h// py+lylqiences uniform circular motion, the direction of the net force is / lkbpqlp:yhq8/.y+w

  A roller coaster car is on a trackfb j(7ajzp1 9i that forms a circular loop in the vertical plane. If the car is to just maintain co1j zpjif(9a7bntact 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 a circular loo qdnpkxrp f34k*3 5.qbp (radius = r) in the vertical 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 pointkq5r3 p3kd.4fn*pqb x?

  A pilot executes a vertical dive then follows a semi-circular arc untileak9cj dw) h +6;dgh;l it is going straight up. Just as the plane is at its lowest point, the gw; 9l;hc+jk d6e ha)dforce 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 yd3fwkzl:v;vm r/( 0lof 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 constant speed v. Th ycc l5b,ol4d0en it goes around the same curve at half of the original speed. What is the centripetal force on the car as itlo cd0l 4,5byc 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 it gl uy1,oe z+hf*oes aroun1 f,z* eloyuh+d a curve of 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 radius r with speed h z-fb,bdw yy pv8 .kaxfc.:958smhf0 v. If the road is frictionless due to ice, the car can 5p:8d9y8mf-.., kff sbbhh yvcz w0ax 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 hpn v0cnnmq+y.; q ;7dnas twice the radius of the other. The safe speed (nov+q;; p yq0mn7nnc.nd 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 nwq k-s)/ys 6r8 4lirf ywjbh7cjn6)1 increases upward from the horizontal. Coming around a turn, the bobsled team will intentiona6)rwkns-6h48r7sj y bl/nwy i) cjq1 flly "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around aa5xwk-8q enr + circular path to have both centripetal and tangen8-nw q+5a ekxrtial acceleration?

  The gravitational force between two objects is*tqk,wq59 i.bq.tx3hd : vw h z,pwo4l4o)lnr proportional to

  The gravitational force h+scudtgp wnt0,c wr ss46.z5kp)i(1 between two objects is inversely proportional to

  Two objects attract eachyxud hs s:sgf34y;.3k other gravitationally. If the distance between their centers is cut in half, the 3x s:ys4hdgk u.;sy3f gravitational force

  Two objects, with masses yy 3pihs/tg;1 $m_{1}$ 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 masses4*znaua6)f:ch ph-ir $m_{1}$ 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 universa9/j+onpku spyf187 xe l gravitation.

  Compared to its mass on the Earth, the mass of an object ym w2,qf,2+d(aa uqjlqlc49 t on the Moon is

  The acceleration of gravity on the Moon is one-sixth whaywb.l2r,hoxd.v w*) 2gomj9rn * 1nvtt it is on Earth. An ob.o*2ywhjw.l1rr* )2m vndtonx, 9 bvg ject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the r 2gyp6wp0bjlee(ve+5ocket's weight

  A spaceship is traveling to the Mo.:c asd 4lzta a+(bo;gon. At what point is it beyond the pull of Earthz a ad:;agot(s .blc+4's gravity?

  Suppose a satellite were orbiting the Earth ;+xwn. fp2x) b zadxr(just above the surface. What is its centripetal acceleration xd;+nw (abxf)p 2rz.x?

  A hypothetical planet has a mass of half that of the Earth and a radius of twip2 jct,tt/1 mice that of the Earth. What is the acceleration due to gravity on the planet in ttptt c/m1j 2,ierms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what jn yr2: h.yhsg4k 8 p6e7zv0ayit is on Earth. The radius of the Moon is one-fourth that of the Ear:zhhpy.kya2sry7g46j0v e 8 n th. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice 4b(6mzj- 9upakqcbhk(dw5 p: the radius of planet A. If planet A has mass m, what is the mhw- cmpk( kb zp5dj a(4:q9u6bass of planet B?

  Two planets have the same surface gravity, but planet B has twice the ma z:7a7b,j ( utcmn8l qlf.iel:ss of planet A. If planet A has radius l(enl: qfu7 jl8matz b,.c7i:r, what is the radius of planet B?

  Consider a small satellite moving in a circuba3p 7wb(q* jdlar orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital vea w3pqbd*(7j blocity?

  Satellite A has twice the mass of satellite B, and rota2 zmgdsc27eh9 tes in the same orbit. Compare the two h7 e9m2cs2gzd satellite's speeds.

  A person is standing on a scale in an elevator accelera rruzgwei os; e67h92zdi)-t) ting downward. Compare the reading on the zgudhrs2z67 - 9oiwte;)e ri)scale to the person's true weight.

  Who was the first person to realize thata.pxi/;o kfzo xo9 l08 the planets move in elliptical paths around the k 98lf0a/i .oooxx;pzSun?

  The speed of Halley's Comet, lm dw.x h j:y41+kovu8while traveling in its elliptical orbit around the whv yo+8m l.4d:k j1xuSun,

  Let the average orbita *ww dcen)9k*ll radius of a planet be R. Let the orbital period be T. What quantit)kdc wl *e*wn9y is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in 7 khp)p9v ze;u2vt jc6the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If e;t69u vp jc) 7hk2pvzthat 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 defdo01)ltcgvuh37 tzlh bs0b.1 f/qme z bjr054ined as one "astronomical unit" (AU). An asteroi7 50lugzrqbt1bcs3e 01o)l4bzmfj0v/ . th dhd orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.etv8gpn5uove7s.18.qn1 pj j .7xqtk

  List the four fundamental forces in nature.5849 bbtikpuva m:q fx: ,nj3u

  An object moves with a c47p a)ds *n+pomtgm3ronstant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of tha34tp sm m7+*podrgn) e object?

  The maximum speed around a level curve is 30.0 km/h. ha5; iu4 c/bk5icm(h nWhat is the maximum speed aroundkich/u4;abm5n i c(5h a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bib ,vibblc4,:t u: ie/hcycle wheel of diameter 70 cm when the bike is moving 8btc ,:4u/ihbl :, vbie.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axisj 8hw9hi/3a ek. What is the centripetal accelek9hwaj/ei 8h3ration?

  How many revolutions per minute must a circular, cfp kf,9woo 0.rotating space station of radius 1000 m rotat f9 pkowo.f,c0e to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at gn, dwbh7-,e on-yz g)96.5 km/h. What is the centripetal force on ybon eh,g-n-zg,7d)w the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirlv+b7d,7i+ aqxx/ uq1rkh n 5bped 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 if the string 1 x bnbui+,dv7xaqrkp/ h+7q5is not to break?

  A stone, of mass m, is attached to a strongfh tnd p8y5f39m6il h cos(t56 (mx.ul string and whirled in a vertical circle of radius r. At the exact top of u(f(dx.3 lm6c5hym89t f65p thl snoi 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 stone, of mass m, is attached to a strog1v sa*lf o-q,ng string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is -a *of1vqgl,s3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/h1a4op 4n) a m15wc4iewafbs 6s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of 1ba)o54hwn4 epcs61w ai4maf the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the centev-jag/;th5hdy fiyh/ vyr,j+x( ;gm)r of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with onlhtd)hv,;fr gy; jj( - a xyvi5+gmh/y/y one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven timepg2rg: 0dwy- gs his weight. What is the minimu2gg w- 0pgd:rym radius of curvature that a 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 rikj,i/3dul 4eel1 b+ iounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires e4b,1 iii3u k /d+lljeand each road surface.)

  A car is negotiating c; :rn;rhd23 qwav)xy;5f nnya flat curve of radius 50 m with a speed of 20 m/s. The centripetal force:a;fny) n2ny h;vcwdrxrq5 3; provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat culz 06sv. , bdzt8t0y qril5wi-rve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the roatv0,8d0zsb tlr6.w-y zi5qli d for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coefficientr:b4 jjaxru)a verz(3)qewv l8/ v9l8 of frictione)9 )rq8 rurlv4b3:aw8jxv (jazl/ev 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 required for an Olympic bobsled t 05.z8lngkd xco negotiate a 100-m radiug zc. xl8kn05ds turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run i tqt3ofuq( ;t;s 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, banjmvx.n1pc*z22nauu.gt8m ; g ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80cjpp)xg 82or0 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 sy/cla9-/djjp, lik vrq5m-s ae/7v2 in a horizontal circle of radj ,l-//rd2/v-9s q yav5lspjc ekm7ia ius 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 acceler jyxyuuw(:97+/fzuh rates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only 9f r +hzuw:yu/uyx j(7fill 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 oo nlgg: hapt, p+*(bo)f 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 c+i1,vg8gud n wg(t9 jon the Earth, due to tcwg9t8g n vd+1ji,u g(he 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 mr fa6fl+x0 5umasses is F. If the masses are moved to half of their initial distance, what is the grauf 5 ml6f0arx+vitational attractive force?

  For a spacecraft going from the Earth toward yvxy9 nhq) 3ubg; 8be;the Sun, at what distance from the Earthvqby )xngbe; ;9y83uh will the 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 b tsgre f,8 9upxqoar3ob vb)-k4z ;3,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-walk" at a distancebk ch4znyn4 b26uj z-+ above the Earth equal to the radius of the Earth. What is her acceleration due to gravity? 2-nzzy4kn+bchbu46 j

  The radius of the Earth is R. At what distance above the Earth's surface wil cd8so6s uy(ziq 4/:uzl the acceleratiosus6 qo/z8ic (4z du:yn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its sur+f -uxc0 8 r9mo5kbakvg*v(b5t3iga mface equal to 3 times the radiuf tg bbmo(3-kv5i a 8+rxg0uacv*m59ks of Mars. 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 acceleration3hx w k l-nj0dm-03fve of gravity30 vjk0hn xf-d 3-mwel 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 radiusqabi) f6no36 7ghy ll5 1oei0h r. If the object is raised to a height of y0b3)qo1hgi6 if57n eao hl 6l3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes from 7mcxh,26y5nw itfc9 isea level to an altitude of 5000 m? (The mean radius of the Earth i9wf t n2 76yc,cii5xhms $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg i+tod)on;t qon1+j r/y :5rmiws at a point 3r above the Earth's surface+r5:wnr/od t;oi t j+1o)mqny. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its hh;4rsstrh*)l 9v irt-.g5zkradius. If a jar of peanut butter weighs 12 N on the surface of h5tr 4gsh .srz*kt; vrih-9l)the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, i3gpll,+ d-hw-vqfak4 h8-bgthe Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass ofl3bpd 84h-lv+k ihf -ga,qwg- $7.36 \times 10^{22} \; kg$; 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 tec nt+nl1zgry8 9/box 6h 4auoz( q:h*o 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 t7/q- hwp;cq9 y/c6i4a y1ed4pr rlkonhe Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite?paqly rro/h4cek7 nd/9q;i6- w 14 pyc (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i9osg5pl5b b p b/ jg,1vfm(n-b.e., it just skims the surface of the Earth). How long does it take to make one revolution around tv55f( ,pn bb mj glb9g-/pbs1ohe Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abovn:e.zhz nu 2 mvn/j)3ye the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Eartz zm3 u2 .neyh):/jvnnh? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diaezex3f s,-0ee meter 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 radius:di *tlv iy7t(6 hla dfm3mz(- 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 nearl(iddg n63a9.)ii qgms y circular orbits. Moon A has orbital radius r, and moonq. mng di)s 9ida6i3g( 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 yyo,iws qk-d9 phbv:1;tl /jij, n4b8 $7.78 \times 10^{11} \; m$ 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 orsdxu4 c1nc;1+j sw7eibit the Sun once. What is the average distance from Jupiter to the Sun? (The7n+1ew 4s ;csui1 djxc distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)