Is it possible for an object moving with a constpht;7 9l jni5jant speed to accelerate? Explainnj75hipt9 jl; .

  Consider a particle moving with cory 9kd6w)fmy ,w)xn6 jnstant speed such that its acceleration of constant magnitude yrw)6xjmkwny , 9)df6 is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the di2 fx u40wd-0gu/r*iu l9o7*qihl mvxr rection of the object's ve-4di fqllhgux*u0uvw7/i om*0rx92r locity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accekykb nfxu*2:9-ki st5 leration b-i2k*kxyk:su tf95 n is

  Consider a particle moving y m,8obbi)o 5uwith constant speed such that its acceleration of constanyo )ub5,bmo8 it magnitude is always perpendicular to its velocity.

  What type of acceleration does an praxy;uztr, vp6: :x: object moving with constant speed in a circular path experier:txa; v,p: pyxz6ru:nce?

  What force is needed to makbwn4 ,1myrmya1kh (lp+r5pm0 a5*j zke an object move in a circle?

  When an object experiences uniform circular mot,g,jkbgam.)m2 x ikn.ion, the direction of the net force i)g,..gx ajb, nim m2kks

  A roller coaster car is on a track that forms a circm ktfxzgb3a +x*:r-2jl u*,*jipdi p 2ular 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 acceleration at thi*kixp-m ul, bpz: gjdirj*3t*22fx +a s point?

  A roller coaster car (mass = M) is on a trzdgh wf h1,+ :a63hhgpack that forms 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, what is the minimum value for its speed at gh h3 :zph 1wg+ad,6hfthat point?

  A pilot executes a vertical dive then follows a semi l,*s/ei -:z73 a8gmj5ra1hg vofwgbk-circular arc until it is going straight up. Just as the plane w gsz7a1 fg-bv8kg hear53,m*j ol/:iis at its lowest 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 radio*a7y/-6ucrzaqw aqh, o98z/ hwkz)f3e4jraus $r$ 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 const,ezp h6h4e4 agr b0o)br86n5dks t)qk ant 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 ga t)e4bsnbd0 hr5r ,k8o6hk4gzp 6 )eqoes around the curve for the second time, compared to the first time?

  A car goes around a curve of zkwzp)jj *0 ssa7u5+;+ pldbzradius r at a constant speed v. Then it goes around a cud* )u+ajk; z5jpsbz0+ 7zs lpwrve 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 sper egce t1ai8+r +m.87mb2yql4dio,kied v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force onrmq4coi,mbl.a7ie8e2 grt +dk8 1 y+i the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same anglik:l4 rdz39t yflb9u*zpi 2m *e, but one has twice the radius of the other. y4pid* u93zri9kf l:l2*bztm 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 turmi b2hs0a bo+:n on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, : 0 b+ishabmo2the 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 a circular path to h2btnenuy39 r 6ave both centripetal and tangentiny9632nrt e ubal acceleration?

  The gravitational force between two objects is proportir /:p+e4f;k;btpw4thuzs+ h )ydc+2/m lgtvzonal to

  The gravitational force between two objects is inverselesqc/ +)kd4uvf0ror* y proportional to

  Two objects attract each other gravitationally. If the distance between tii uyhz*a,i8hvmh: 70heir centers is cut in half, the gravitational foh: *vz8iiu,a yim0hh7rce

  Two objects, with massf5 zqb+7 bkto2(y,q.l y1rkcjes $m_{1}$ 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 mash,mq050ymijsty 5w 1djm(pe0 ses $m_{1}$ 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 gravit-*4+c5 vyf+f koo6sp 8 tyzqthation.

  Compared to its mass on the Earth, the mass of an object on the Moos: k47z4 vbvx .wi/sion is

  The acceleration of gravity on the Mooncwlulv2e3gny/a(* c 7 is one-sixth what it is on Earth. An objeclwu(nac2 vg*ly 73e/ct 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 rocket'knmaa jt74;rpf-a o :3s weight

  A spaceship is traveling tow3 3gba/ * ibf0hoxmm7 the Moon. At what point is it beyond the pull of Eartb* f7 oim03x h3gabmw/h's gravity?

  Suppose a satellite were orbiting tu e7c tgz+ku(m0wl,bkr )zyov g.m09-he Earth just above the surface. What is its centripetal acceleyw t0v 79gc ,zo.grlu e(bzu 0m+kk)m-ration?

  A hypothetical planet has a mass of half that of t8sy,yl4t;y cf acig:3he Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at t yyfa3 8:cgicy;tsl,4 he Earth?

  The acceleration of gravity on the6)cj3yby 9*cye rtsvxbt x26: Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth tha*3:bs)jey69 y6x t2rybv cctxt 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 thef bykz54 a8s v0/khb+u radius of planet A. If planet A has m5fukb + 4bhskvyz0 8a/ass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice b,d4un5 g5vbz4zmq+- lu(vqt56w mpn the mass of planet A. If planet A has radius r, whaq54d,5wn4mnu(tuz+b 6z5bvqp g l- vmt is the radius of planet B?

  Consider a small sate. 48d 7buypjtwv:jw;f llite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression f 4juy wjd8w:; 7tbp.vgives this satellite's orbital velocity?

  Satellite A has twice the mass of sat) 5w+i bd3c/8huoe nqsellite B, and rotates in the same orbit. Compare the two satellite's speedchn5q odse /3+uwib8) s.

  A person is standing on a scale in an elevator accelerating d j+6.h vlsodu/ownward. Compare the reading on the scale to the person's true we u6j+l.dshv/ oight.

  Who was the first person to realize that the planets moo mo7e0hxa /75naqler034.l3vtfmm pve in elliptical paths around the0 epm3llfv3oxq eh aom77nt5a4r/ m0. Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbii*jtvb0gby o* e(z adb/))cr/ f(5 5:gi kbqwzt around the (:dob/j5)g 0(f iiakbyv/*w zgbr* )zeqc5 btSun,

  Let the average orbital radius of a planet be R. Let the orb,yw) zsf:w3 v3qe wt5vital period be T. Wh w)swwefvz,3vy35:tq at quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in thmco:9x9 c5pk ee 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, comc995e c pko:mxpared to the Earth's orbital period?

  The average distance from the Earth to the Sun is definex bg) 0zege+d2d as one "astronomical uni02+) gxzedge bt" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.+bj)zpp bqk-8

  List the four fundamental forces in n)v6bv4t/7k au3fp x5r9f otunature.

  An object moves with a constant speed of 30 m/s on a circulargf7 )d iha8 v(eli4pc8.g,co z track of radius 150 m. What is the acceleration oh8,i8ez l.)gg 4 vofcpicad7(f the object?

  The maximum speed around a level curve is 30.0 km/2ju c.c +ug4 oyiz5 cx*,6wxyrh. What is the maximum speed around c,cw +cx.u45 yg*ixuy6jo2 rza curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on tbox.7em/t3y*mj8kzcmw5 ;9 lra oyw kze1. m3he perimeter of a bicycle wheel of diameter 70 cm when the bike iy c1xabmje8eyk t3m7mlw. 9. rko5z;z3 mow/*s moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis.eyxu/hq r :r:7 What is the centripee:7y/ :xurrhqtal acceleration?

  How many revolutions per minute must a circular, rotating spacz obidcj(4k6kmp.d*m*ng6eyd6h w4rlo, e98e station of radius 1000 m rotate to produce an artel(4,mym*.66 kdedjw9c h p o8i*dbr64ngzkoificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 1((l)j 8zdmco1 x;-5tt5t *ac pirezcxnm(f dm radius turn at 96.5 km/h. What is the centripetal for)re tz(1j(otdcf 5n pil8a;z*5-ctcxm xmd ( 1ce on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirledz p ts2wj9mu27 in a horizontal circular path. If the maximum tension that the string can withstand is 350 N.s2wj7zumt 92p 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 whirled in a 148p.(u vkjc wdso icoil/3;kvertical circle of radius r. At the exact top of the path the tension (4. lop8o w3k1icd cuk;ivj/ sin 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 t/,+utlwvmy;b 1udkt/ o a strong string and whirled in a vertical circle of radius r. At the bt+vu;yw mk1/ ld/,ut 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 puf0rn/kp/x z/8 sbkn a7lling out of x rabnk8zpsfk0/7 //nthe dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of rt:e+: .v7qa 2mpcypjthe loop is beneath him) of radius 3200 m. At the top of hirp:jptqc a+2y v.em7:s 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 isq/x 8i/xf bj/ qn)9fbs about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a verticalq i/)f/sjb fx/n bqx89 dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve wiwtz74eh7 ifz2f/rq 1vth 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 zeqh4w r f17ziv2f7/tand each road surface.)

  A car is negotiating a flat curve of radius 50pr 3)u*ds3w* h7av omg m with a speed of 20 m/s. The centripetal force provided by frictgv3h7aro) u*p3 wsmd* ion 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 odzudmh2 2gv,.r6.wv //gnwmf f 14 m/s. What must be the minimum coefficient of friction between the tirm..v/rdw/ 62uvw2g fd z,mng hes and the road for the car to make the turn?

  A car is moving with a 5 mizv.uc wqjo8,/+en constant speed v around a level 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 the rw+ocn8m .v/5e, uqzjioad?

  What minimum banking angle isblsgul7js 0;egk+ eh 2v7f20l required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frhvu sj220 eb;s7l 0f+kglg7 eliction.)

  A horizontal curve on a bobsled run is banked at v +zur+1vcguvzt *4* -mtpml: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, t*eu *qcef+pq4p4y 0 dbanked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 pt-neza9t 8xokgb)6 3m 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 hori0:/kdw xhgtf0sxf 4m(zontal circle sw0d4/f hxk 0fm tg:x(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 thennb92z sbl 8ws4,a t2u pit area, a race car accelerates at a uniform rate to a speed of 4nnba sts4l2bz w ,82u95 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 protqt5f(e hhib,* a* 3rdgon 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, 5piz79tw1zwn gle)1l:o8mn t due to the Moon? The mass of the5z98)z:gi np w1tw1lmt 7enol 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 hts,r-x *rkx5 g 6g4baF. If the masses are moved to half of their initial distance, what is the gravitational attractive foxh6r,4sak-xg 5b g* trrce?

  For a spacecraft going from the Earth toward the Sun, at what distu3vg+bj/0fmzm f(x 5 vk,r ;d9,acluoance from the Earth will the gravitational forces due t /,vu(o,drk jabx u59+0lfcm fzmgv ;3o 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)yj p7 qmp*i i +ttwd74tx/i.hs $7.4 \times 10^{22} \; kg$ 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 foe+wbrpfz982uz/peafl cvpp )/)xg0 7 r a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due lp2 c+ z v9/)e8ge /7fp wrp0)xzbpufato gravity?

  The radius of the Earth9n c amwz)sd,; is R. At what distance above the Earth's surface will the acceleration of grav;n,dmwsa zc9 )ity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abo .vk6q/ug (jx3w.tvpxve its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars,u3xv (kxt/vwp .6q.jg is

  At a distance of 14000 km fr ,adc9cp6rl (wom some planet's center, the acceleration of gravityrccw ,6 dl(ap9 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 surfacecq;s wh8p;p 00/lxzkr of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's pc0/sr ;zq plkh;0wx8surface, what is its weight?

  By how many newtons does the weight of a 100-kg p(,) pzfyen sv8erson change when he goes from se8zspn)e,( v fya level to 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 ,t7gd*;:j(gc+nsyre oix r/ a kg is at a point 3r above the Earth's surface. What is the satellit;r*+ y(itg/j7dc ,r:e g soxane's weight?

  A spherically symmetric planet has four times the Earth's mass and twice ciny) /*zul-eg.q;guv 9 m- tyits radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on yeg-tiyv ml. - 9;ucu*nq/)gzthe surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, withcr+ /im(frd2 g the Earth between the Moon and the Sun. The Moigc2+ ( r/mrdfon 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))bukil2i-* u k8rrabrted 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 tult9f/+au ,)5ahfrn x he Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of)ffu +9la,x nruha t5/ the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about j)zi,bn u:,b mthe Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius,zju )ibm,nb: of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. wz 82 4pya yjjwh1*7xdIt is observed to have a jj a7h*2 dx8wwypzy14 period of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an-*wgw 8n4kx hvx gdo78 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 o6m.t*co bqwz vs8 k0gy* 8wf2grbits 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 in nearly circular orbitsqcym5l-vmn.c : 6phc6 . Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one vq5:clcch6nmp 6 y-m.orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isik-: xw* + pjenn-kqe) $7.78 \times 10^{11} \; m$ 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 smoo5 b;mk :gy/4l*0h 5q wrflSun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Su: 45om/ oyl 5 ;wqfh*srgb0klmn is $1.5 \times 10^{11} \; m$.)