Is it possible for an objo ji.f f ,q2mvxt(c(15zv )relect moving with a constant speed to accelerate? Explai2o)fi.cevr,lqtz (f xm 1(j5vn.

  Consider a particle moving with constant spct:- h yoa6t c;/wxgb0ou8(lpeed such that its acceleration of constant magnitude is always perpendicular to its veh8:t ou;xty(0-cl6cba /po g wlocity.

  An object moves in a circular path at a constant speed. Compare t8mh-m axa 230ohrwakx5 f1xg3he direction of the object's velocity and acceleration vectorsrxgh1m2a kf35o8ma0axw-3 hx .

  When an object experiences uniform circula p8 ku- uu4do y0rtp1xr1 ojwl9dv0f31r motion, the direction of the accelera rwvyjpo9d1u0pkf1-u1l083odu rx t 4tion is

  Consider a particle moving with constant speed such that its accelewerhl u))-a gnhc* j28ration of constant magnitude is always plg wja )e)8r*c2hhu-nerpendicular to its velocity.

  What type of acceleration does *lsu9u s;-:m e8g vb26noucazan object moving with constant speed in a circula ucu29bm6gl -;ea8s*o usn: zvr path experience?

  What force is needed oy5yr0( g7c8 /i fltxito make an object move in a circle?

  When an object experiences uniform circular motion, thlh0qup.g(:fn1 dq o :uu8i8z8k ffu 5ge direction of the net forf pn(u.qi85 gfuu88qg hud: 0ol:zfk1ce is

  A roller coaster car is on a track that forms 2w+yg,c9sv (0 njuiyo a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, wha cgn +,o y2w(y9ijsvu0t is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass mxzwafy8 6g- *= M) is on a track 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 f ay*g8mx-wz6value for its speed at that point?

  A pilot executes a verticalqs 9;sc;bvpzjdr +gqn0.yk1 : dive then follows a semi-circular arc until it is going straight up.0:.dqg+b; y jn1s9zc qpsrvk; Just as the plane is 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 ccg tx/25,rfeo-m/x(ovfk + wcurve of 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. 3r(kqfmbi2 2 u(bo b lf1ci31m-/ ib rgut)h6gThen it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for th ri m-l22kofuci1( b(t fgiq b36mu/b1bg3h )re second time, compared to the first time?

  A car goes around a /d k 2tvg3-cnu)r3yqycurve of radius r at a constant speed v. Then it goes around a curve ofry 3yk/c-dnvq2g)t3u 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 v. I ,(8xvjpwt y1qj,ps+f i *io8v9;yvxof the road is frictionless due 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 ma v8p9x8v,tjpx,iwy1o+o(*ys vqj; fignitude to

  Two horizontal curves on a bobsled run are banked at thegzy;(ui(t73oj twy+sd;6yg b 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 the safe speed on the larger radius j 7wo ;yi zt (b(y6ydts+;g3ugcurve?

  The banking angle in a turn o;gx*;;j sbj 4f jinmw0n the Olympic bobsled track is not constant, but increases upward from the 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 jjgnw ;* i4xm;b;s fj0this?

  Is it possible for an object moving around a circular path to have both centr8 vccx5e; bd4kipetal and tangential accel 4c5;xek8 vdbceration?

  The gravitational force between two objects ggfcu6j 9(5(f 6sxx lv)5fyy5mege k8is proportional to

  The gravitational force between two objem 1*.vf eu5* z4qvfwkic7qhl 2bad;b 3cts is inversely proportional to

  Two objects attract each other gravitationa0 k61ea nd6( tpyg6)peo7gi nzlly. If the distance between their centers is cut in half, the gravi6 n1gpd0gnee67at6()pyk o zitational force

  Two objects, with massu ,s92i4s( sd d-zvh7bowi y6ges $m_{1}$ 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 vem8f4oy.qf j/q(oh z - )zbk3$m_{1}$ 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 d8k9q 8ap2klegravitation.

  Compared to its mass on the Earth,-fhh a2: iw6rp the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on *0 1cs36sssp,d rw+wqpc wt/eEarth. An object of masqss36dwrw s+pwe* t ,sp/cc0 1s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's we38f0zeohn (achr:b x2o mh57eem .wz*ight

  A spaceship is traveling to the Moon. At what point is it beyond the pull o d91blm ,urz/fb zlq yg6;(0hof Earth's graviyl/o1lmbrd 9; q f,h(buz6 0zgty?

  Suppose a satellite wergrvedy4: (:p5 aaoa ,ye orbiting the Earth just above the surface. What is its :a4a(y,5e pa orgydv:centripetal acceleration?

  A hypothetical planet has ad:n x5iszp;) nq8+of o mass of half that of the Earth and a radius of twice thats:zoo58q np ;+fx)dni of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity (1 0zftimx 21 v +ppynk(7/z5 vvodpiion the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass comvo7t5pi z p1 kf ((n1z0p iy2v/vimx+dpared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the9p-;w)*v3fkl bl dk la radius of planet A. If planet A h fl lwv3d)*9lbak; -pkas mass m, what is the mass of planet B?

  Two planets have them8zk,/m 4tr s:ddv1e v same surface gravity, but planet B has twice the mass of planet A. If plan : /,vv4md8 dktr1ezmset A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) abouktw 6y 1frgj(,t a spherical planet (mass M). jtwr1fk, g (y6 Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, p1 s,8 7eplzt.jyj5ep u-n 5hpand rotates in the same orbit. Compare the two sajhp7uppe,l.58j y1pnste-5 ztellite's speeds.

  A person is standing on egtq/s-jpo,3e3h-w 5d h.opqa scale in an elevator accelerating downward. Compare the reading on the scale topjq-/ dh,q . o-3t5osp we3egh the person's true weight.

  Who was the first person to realize that the planets move in eicamq,c j -9wc46ioee88mbs) lliptical paths around thc ee8os j68q,i9ma w4cbic- )me Sun?

  The speed of Halley's Comet, while traveling in its elliptical o m9ow3fy6etpecd*mx7,l ex/; rbit around the Sum,7eymd;xwf6l tpoc *e39e / xn,

  Let the average orbital radius of a planet be R. Let the orbital periodg2v d8bwt(2g g be T. What quantity is constant8vggb(tw dg22 for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, wit6kon(y ;6 +:9irkhne0 hqb uaeh the same orbital diameter as the ee6o6kuyb0q 9:hnh n( k;ar i+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 the Earth to the Sun is defined as one nm2z1 :6 hyjif"astronomical unit" (AU). An asteroid orbits the Sun in one-thim: 2yfn zhj61ird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.cna31mi x*.(+z leukq

  List the four fundamental fors*fx*hh+v o*m ; cmy u3/tt)uoces in nature.

  An object moves with a constant speed of 30 m/s iopo(( 32snabw9vd(zon a circular track of radius 150 m. What i a3( 9zn bo(ovwp2(diss the acceleration of the object?

  The maximum speed ar d, 0zq qhfc::f;pck8sound a level curve is 30.0 km/h. What is the maximum speed around fqsfd;,p q :k c8cz:0ha curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the: kkpg1tt/:n+sz +bcn perimeter of a bicycle wheel of diameter 70 cm when the bike is m1kn n +g:b/skc+ tpz:toving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.20 g8vrvcp+ ,i)b7ylz r/g7nj)f 0 m from the axis. What is tg8) ,irgb7 n7p/vy)r lfjc vz+he centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of ra kn sn2ux9ssvt i/g9ehl)oa9:l3(l8e dius 1000 m rotate to produce an aolu(xgev9ni92 :/sest3lsa )9n lk8hrtificial 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 9d y0ypbxt a)f+3-g6 ,)vgerzv 6.5 km/h. What is the centripetal force on xv3 ev grf0z, py+tdy)6ga)-bthe motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whh f6(qm 0ysa sai*,;jeirled 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 is not to bref;s(0 s a,yjqamih6e*ak?

  A stone, of mass m, is attached ;bs - wk6 gu8z1 1q(e gcsjj*vuv4qry(v05y gtto a strong string and whirled in a vertical circle ofu;e4gsvtcykgy8jqv1 (j -qu1gb6* sr w5z0 v( radius r. At the exact top 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 stone, of mass m, is attached tobd;2 ckk rgr1om/4h6j 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 weighm4g6rk;rkbd /j oh2c1t. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration 1 zjr)xlat4 b4of 4g when pulling out of the dive. Wh r4tx)lj1a 4zbat 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 ofrf *saed8v2s-ea1v t2 the loop is beneath him) of radius 3200 sdrvafs 8e t-12va 2e*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 going?

  The maximum force a pilot can stand is about seven times his weight. o2cu.v8nw4k6 8btg cnw0jkf6What is the minimum radius.4otkcjuf086vkg2 8n6b w ncw 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 rounds an 80-m radius horizo* cueg8 m wxat/pgf(6.ntal curve with the tires on the verge of slipping. How fast can this car round a second cug8pa ( /.wm*teguc 6fxrve 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 m1*v5upnvqvi w si5mxu*99e:m with a speed of 20 m/s. The centripetal force provided by friction pumi9**w9im:v 5svqe 15 nvuxis $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a spjhycecy-k b ld4; hj/8j/,+oo3j6lhyeed of 14 m/s. What must be the m/8jk /o hyh3oe lj6yc+ ; bdhjcljy4,-inimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constanku(*) b rxq r7xr)naxqsn8b-nd6t.g9t speed v around a level curve. The coefficient of friction between the tires andrxux -. q)nqan tbkgr7bxr)n8 6(9d *s 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 Olfpuw1azdy x a.k+j.3 7ympic bobsled to negotiate a 100-m radius turn at 35 m/s without sk ad.zfyj+pu1. a 3kx7widding? (Ignore friction.)

  A horizontal curve on a bobsled runar :qw(m4tdno2k hs8 , 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 a**ux;mk s- lq 5/uejxzt an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m isew+, 7nytgu o-8tsl 5g 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 revy93e.,zma-*/ zukk 4ppcnfwt olving uniformly in a horizontal circl.4,w/ k -me cnay9ut3zpz pk*fe 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 the pit awn 4- ,ormhg( lid3d,xrea, a race car accelerates at a uniform rate to a speed of 45 m/s in 1h dndw-gr, 43(m ol,ix5 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 masss +j6 adcae(9v $1.67 \times 10^{-27} \; kg$ 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 standiiw)x9s9q(h :7mnmm/+:yfe/ pwx hqy hng on the Earth, due to the Moon? The mass of t ihy y9:xwh+ :9epm(7fx)wmsqn q/m/hhe 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 F. ) bgo(s:na3mkv k (h3n If the masses are moved to half of their initial distance, what is the gravitational attract(s3 ()ga3nb: knm kovhive force?

  For a spacecraft going from the Earth toward thn2l6et, n 2vdcc 7/dfxe Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cancellnn/dv ce26xd c7f ,t2?
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 Moond0jlucrb* c4rby0b1, 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 for9c nf z9kue0anj:k8 h; a "space-walk" at a distance above the Earth equal to thnch 0:j99fau;zekkn 8 e radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will tj5 ,ml3sgfg pfbt(35b he accelbp,3gs35gflj5 btf( meration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfaceyxt e zv.b:9b+ equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity zt.: b9x+y bevon the surface of Mars, is

  At a distance of 14000 km1v.y vkhoeb1hr 0z+ ma+ (+sgs from some planet's center, the acceleration of gravity +0h 1vo+z h (seym1ra.sv bk+gis $32 \; m/s^2$. 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 E ig -wgsk2j251hwcvb,arth has radius r. If the object is ra hcb- 1j2k5swg,gv2wiised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1xc-n xqq,71b0 g q5obr,7x2 ewrtr,oy00-kg person change when he goes from sea level to an altitude of 500 bwxr1,qxr0o bex,r-g72nyq t5c, q o70 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 point 3r y273hea1t 9mu1kynop2 qayk*above the Earth's surface. What is the satel7 ohq 9y1p1an3 a ymtue2kky*2lite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its)k8z*p q 4vsbg7*)/aqu c eosa radius. If a jar aq s)7bku p)*zs /eca8ovq *4gof peanut butter weighs 12 N on 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 6 /q4gox(tco1e4 doks on the same line, with the Earth between the Moon and xs4q(t ge4 k6ooc1d/ othe 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 transporth*bshf7k*yb rb8mo6,ed 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 t(s:zdgr)i2 )d r,qqu-jaw d8ehe Earth (i.e., it just skims the surface of the Eartrqj )r)qe,s 2di 8dw u:d(ag-zh). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a loprbsrqf qg4xo)4y ,. we1 tf. aa;hb87w circular orbit about the 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 of the Eart arf4hbqw).btoyq, f sgx1a4 .8re7;ph is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface ofrp(5yz zj(jv5fs+1 t jk;bx/pyeh +,g the Earth. It is observed to have a period of s (/ztz1xj5j( pk yg+r5b ;vh,+pejfy 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 orbital r2lp 6m:+7lit7l /fhhyg 8cit 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 Jupiterd39 9qdv86o*ug oh xfz orbits 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 orbits. Moon A has orbital rad wzubzc9ir3zf(gey(doqo)( +me1 ;6iius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon zyzc 9ug3) ( f (1+wieemrbqzooi6;(dB to complete an orbit?

  The planet Jupiter isk- wcl3n4/tel $7.78 \times 10^{11} \; m$ 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 Sun on lrgpiun 9jbb895;tf/ce. What is the average distance from Jupiter to the Sun? (The distance from the Eart5g/bj f bntr9; upl9i8h to the Sun is $1.5 \times 10^{11} \; m$.)