Is it possible for an object moving with a constant speedao(+6ys 7vs4mias+4uf lk dm + to accelerate? Explain i+44uo ak6 vds(samy+fl 7+sm.

  Consider a particle moving with constant speed such that its acceleration of cop xas d4 i42oo5l,i-twnstant magnitude is alw5 x -os24plt,wi4aoidays perpendicular to its velocity.

  An object moves in a circular path at a constant6m)-4 lam5 pnwhwgf.gh3q2hi4 6d2urra0 ew j speed. Compare the direction of the object's velocity and acceleration venh jhqd2g6iwafe a w)r642u .5mg3m w4-hr p0lctors.

  When an object experiences uniform circular motion, v/) 4gp,cl;t- ebw la6ilszj6the direction of the acceler );sea ptlwlz-vlc4jgb,66 /iation is

  Consider a particle moving with constant speed such that its accelerati++tkj /7pto v(-nooz ion of constant magnij otzt+i/( n7 p+ovk-otude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constanthu.0*dbmd .x6xfnch 7 speed in a circular pa fn60. hxm ux.dhc7bd*th experience?

  What force is needed to make pe8,i(uy8ptx an object move in a circle?

  When an object experiences uniform circular motion, the direction of the(xoq yxj84( 59vwibw t net forx(vyqw9 5it4x (bowj 8ce is

  A roller coaster car is on a track ,rwgv+6 5x6py hdsgy 3that forms a circular loop in the vertical plane. If the car is+p,gw 6sd hg3y vrx5y6 to just maintain contact 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 ksf(qwwmvi dveo4.c07 x . ;4eloop (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 tq0.dv c( .wo 4xk 4efi;emv7wshe minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circularw) m8kv-faons5j3zy/fq0+s56x ssq1jsfh/r arc until it is going straight up. Just as the plane is at itvs raq1f3z5)50kojf/+h s6 8w-sjnxfss m/y q s 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 radius; cfqp 1(i19p vs(rwcn $r$ 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 spl wk22ni zc-j*s+hgp3 eed v. Then it goes around the same curve at half of the original speed. Whphs i23kl2+ -g*ncz jwat 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 constant speed, fooi al2ad3 bbwb2* n*sx(:p v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car f3obpbsodnwb *l(ax*a2,2i: as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of pvvkuumy;nu 6e77 0k+ radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component v;6vm7uy7uek0 nu pk+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 .i*a ( qkeg,hpangle, but one has twice the radius of the other. The safe speed (.pi kh (eqa*,gno 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 n ;v:n6ibo /hk7;vu nz hrc8r-l r;1y0okv z:econstant, but increases upward from oz; hur y7vhk :zc: -v8 0n1;lvnnbkoi/;6rerthe 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 this?

  Is it possible for an object moving around a circula)m uxh+9wzw,)y p :s hs/,65k6gjbyed bh 0tprr path to have both centripetal and tangentikwgh/hz y yuph6)0md+ s,9r 5wxb pe)stj:6,bal acceleration?

  The gravitational force between tw4po 6*w(ib0int hfxzs ebm*- :o objects is proportional to

  The gravitational force between two objects is inversely proportionwe3j,w/p osj7 al to

  Two objects attract each other gravitationally. If the distance b8a k:5 htggve99(dk ;w:pu)v s pmm0zpetween their centers is cut in half, the gravit8gg5p0 ka;hts pzp9d) mwmv ::u(9vkeational force

  Two objects, with masmfuj3lsg,) u8ses $m_{1}$ 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 mas)a.evr3.rgsm6uzsl b zj h*)0ses $m_{1}$ 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 gravitatiocy sh0(xc i.2j. ozs2uhc4-yen.

  Compared to its mass on the Earth, the mass of an object on tf 0dj :4 6ixzy+ojfu36fj(-r g,jlhoohe Moon is

  The acceleration of gravity on the Moon is ujr9ue /1d q.pone-sixth what it is on Earth. An obje qpd1rj9eu ./uct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from z(b3wz+m*bckzqfm 8,n:kr2tgrpo gh 85f-s8 the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what poi rwn-61(y qt5qrh njo+nt is it beyond the pull of Earth's gravity? w-r( tr5nhq1 yn6+qjo

  Suppose a satellite were orbiting the Earth just above the surface. Whl-jbes-5 8kux- pn 8h0xk21z1yizis h at is its centripetal accelerui0zhlx 81jn si-h ky1-zs xk-p2be5 8ation?

  A hypothetical planet has a mass of pgzy 8 b1t*qk(u frr- ziq0+k3half that of the 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 acc+q8(3 tpfk u-i0bq1 y*rkzg zreleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is onep 31*hx3 1pynsy u7:sau1olh e-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compp*3 hupxy 3lnao11h1e7u:s sy ared to the Earth's?

  Two planets have the same surface gravity, but planet B has twiy a9 *;vv-gfvkce the radius of planet A. If planet A has mass y9- *vgkf;v vam, what is the mass of planet B?

  Two planets have the same surface gravity, bu)nm yro9.f 0ggt planet B has twice the mass of planet A. If planet A has radius r, what im r.g0 yof9ng)s the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a k(xev8c/ql ;;dmz+ lp pqu3e0 spherical planet (mass M). Which expression gives this satellite'sv+ kq;c( ;lxlez pmp3d/qu0 8e orbital velocity?

  Satellite A has twice yhamy;l qk +lf1;qx74the mass of satellite B, and rotates in the same orbit. Compare the two sate ;a1;4xkflq l+7qymyh llite's speeds.

  A person is standing on a scale in a+xb6z,t lih9n. olx7 vn elevator accelerating downward. Compare the reading on the scale to theo x+l n6,i.hv 7zlx9tb person's true weight.

  Who was the first person to realize that the planets move in ellc6qyf+sr b( (0lo( **ekgpnjbt r;88tqh pt8jiptical paths around t*(t8(l kqrts nrpj j bp8y08;6qebtf*gh+(oche Sun?

  The speed of Halley's Comet, 9mz1bm ai4a .4fa s3nhwhile traveling in its elliptical orbit around the Sun,a3i fh1msa4n94 mbza.

  Let the average orbital radius of a pxk/-xtje 91v l6x6fzelanet be R. Let the orbital period be T. What quantity is constant for all planets orbitit/x 6xl x6 -9eejvzf1kng the Sun?

  A planet is discovered to orbit around a star in the galcot 8.c0f*ufxaxy Andromeda, with the ut0f *fc8 xo.csame 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 period?

  The average distance from the18+ud0hiaa x )5pfk nt Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. Wh5h dt k8p0un+ax1)afiat is the asteroid's average distance from the Sun?

State Kepler's laws..y 3hi 2* nib-(kpq*cq aoyd*k

  List the four fundamenaj 6 l vakqhcqc8gq(2 h69 xli23ts2a;tal forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radius 1pgm07fq wrma+ 8gh93 g50 m. What is the accelerrg0+mp hgw3q mf 9g78aation of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the-o 7c9 nra0zt, 6/viq.v gdqkx z38ctd maximum speed around a curve with twice the radius? (Assume all other factors rk0-,tqi v / vcdzao7tn. 8zrc9dg3xq6emain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bi/ oz.fk9 ioxqys,+j e0cycle whee/0yio9e.o fq,jxs + zkl of diameter 70 cm when the 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 axi15r/dib 84d xpskkl0f s. What is the centripetal accelerati 4l50fxkrp8dksb 1/idon?

  How many revolutions per minute must aq6;hc8 h1qilp x:* js,)lsmla circular, rotating space station of radius 1000 m rotate to produce an artificial gr:68j),;x ps qslm il1l*ac hqhavity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiuyxqo) txo 57a7s turn at 96.5 km/h. Whty 7)5qxxao7oat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m -ah2h/zlh pz bm)*vm;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-mz mh2z)h vh p*lab;/ mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirledd6s2r1ut 8fn w nuc w/r0(hwx3 in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 timerdr w 0fcnn6w2xu138swht (/us the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, isjd ej)t1)l-ta attached 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 stone's weight. The stone's speeaj)-jl d)1t ted at this point is given by

  A jet plane flying 600 m/s experiences an acceleratievl 9rj,h7jc e9te1 d:on of 4g when pulling out of the dive. What is the radius of curvature of t 9 ve,jetl:cr1hed97jhe loop in which the plane is flying?

  A pilot makes an outsi k0j*b pojd8we(*8 vywde vertical loop (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 weight. How fast is he goin8b*ywwjp( ejk *d8v0og?

  The maximum force a pilot can stand is about seven times his weig l+6jw-9dae - lvh3gzm*my9g iht. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a ver-*dv+y - 9az3ge6m ijhw9gmlltical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius hori lm5.0kj,m ntszontal 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 tirm0j,msk nlt5.es and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a z-,36mkrdyu f speed of 20 m/s. The centripetal force provided 3ky-m f6 du,rzby friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cufsym*vks 5 fl-.e 9:jgpo1 y4qrve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make pe m5q9sjl*:.v4yks 1-yfog fthe turn?

  A car is moving with a constant spe hl(xu n tqa)-qg0)/jeed 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 stah(0g q-)u)nxj /eqlt ay on the road?

  What minimum banking angle is required for an Olympic bobsled to nego rf9vwrh--y6q (/pnyitiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictionr/vrf-i y p 6yn-9hw(q.)

  A horizontal curve on a bobsled runj7cffg0p0( ps r l+;gn is 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, banked at an anl4i0 aegb3 7qt9aovo- d*uyi 6gle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 mt/v- i2ep h)fy 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 ow vn)lgh0;j*/ya htp3f a string is revolving uniformly in a horizontal circle of radius 0.50*ahghl0jnwy/) v;3p t 0
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 acceleratest)a;l . xxs3gm 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 la 3x )xgstm.;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 consistg8*xmx+tnoyopxw9s e-h:- 3 gb4 nq* is of 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 on the ga+zj: :abdz*rv)kp)Earth, due to the Moon? The mass of the Mo+pjz)v)a zg:r :*kdbaon 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 8r:f6) x iw3inb5mu wvthe masses are moved to half of their initial d8r b: x)i3fwn65umv iwistance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance6dnbx fzc w/0tl0 d;6d from the Earth will thd 0cxtw6 d0lb znd6f;/e 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 izelo 33ji 1+-rv8d j/zxo p3hqs $7.4 \times 10^{22} \; kg$ 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 forj,mdt-rf )nfw c+,q.o +n8o hr a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceler,cj8o.fmn t+rhnwr)d f- o ,+qation due to gravity?

  The radius of the Earth is R. At what dist kiyhr m 0tvn(etq:4bon9./w3ance above the Earth's surface will the accelen.r wbq k4tt(:0vime/3hn9 yo ration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal towdy45wh0scu / 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration uc5w /4wdy sh0of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the .gai8q3 5uol vn n6t-j1zc0wlacceleration of gravityznu-anq1j c3g8wv.0ll t6 io5 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 t.;nxt p0 w)8-hvfvv gjhe Earth. The Earth has radius r. If f0.v-;jhv) nvtp8 xgwthe object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he5, 2,2lotbu qorg3buj goes from sea level to an altitude of 5000 m? (The mean radius of the Earth,uobobru32gj 2l,q 5t is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A g i*ekf 9)sk6 (zo3cobsatellite of mass 100 kg is at a point 3r above the Earth's surface. What is the sbz)seg *9iko 3(cf k6oatellite's weight?

  A spherically symmetric planet h82q( :ymc8vlqpvo 5lqqzwf 3:as four times the Earth'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 th8o 8qpm z 3v:yf2w:qlv5q( clqe surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same linhqt():4fi cua e, with the Earth between the Moon and the Sun.)t4hqa ci:u(f 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 Mmvuldm 3,gg,7oon.
(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 abou1rj r(bbg vn3sdd4t4,bd+ b/ut the Earth (i.e., it just skims the surface of the Earth). What is the speedjrb s1( nu vbg43ddbb,t4/d+r of 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., j*0 h 9nfxw9-vxb-agr it just skims the surface of the Earth). Hg f9jv0xhw-b n-r a9x*ow long does it take to make 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 the surface of the Eaq-4tkl7g zz/f e0vtd*rth. It is observed to have a period of 89 mi 7z/-eklg4fq t*0td zvn. 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 orbital6rp7uuo- 9 s bug(dsb. 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 orbits the planet with a radius ks w3;h sf;ruuct 2f0+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. Moon A has a7f6w.hr- (o ffue/wrorbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete hf(f au -fw6 eo/w.rr7an orbit?

  The planet Jupiter is 85 pqjv7cv:sq$7.78 \times 10^{11} \; m$ 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 y +j0jrd,fies7q+m qx 7ears to orbit the Sun once. What is the average distance from Jupiter to the Sr7js xf+edq7 m ,j0qi+un? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)