Is it possible for an object moving with a constant speed to accelgr 2k8n .mw1.n(: g djv/bdnuserate? Explai1 g wgkbn2m8(: s../rdnnj uvdn.

  Consider a particle moving with constant speed such that its acceleratikey4c5.e br )eon of constant magnitude is always perpendicul k4er)y e5e.bcar to its velocity.

  An object moves in a circular psi,btl0x i (a/t,dv z+ath at a constant speed. Compare the direction of the object's velocity and accelst/ad0z+b,, v(l xiiteration vectors.

  When an object experiences uniform circular motion, the direction of tj .tb5 kee3h f+) w+p9olypboq)7q/iv he accelerat+/f lq )q5eio.bwv j9t)3 yopehpk 7+bion is

  Consider a particle mo+pqsunhhlg*eao65 8 d;weh19ving with constant speed such that its acceleration of constant magnitude is alwanp gu 9ee*h+sw1o qd56a hhl;8ys perpendicular to its velocity.

  What type of acceleration does an object moving with constant speeddg/a *l6u,u ek)id+q d in a circular path experience?u * iq)g/ld6au,de+k d

  What force is needed to make anq9 gebxwv 1amn.x2l.z7a*r4mwd)wt/ object move in a circle?

  When an object experiences un2a5fpn:brn ( wu .n(6tfw-z sciform circular motion, the direction of the net force is atfn5w .pnzun2sbc(-f r6 (w:

  A roller coaster car is on a track that fowowa+fsmgh j 92:32ztrms a circular 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 9 :3wmghajf2oz w st+2for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on aws kv f8 u+5k)h7y:qwy track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track k5 yvq:8y) fh7 +uwkwsat the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a n5 qciv ging ,odweb- 6u(s/c52f u;/esemi-circular arc until it is going straight up. Just as the plane is at its lowest posvc5u6 gfgbid/ -i,e5o u/cw2 n;(q enint, 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 o u0v8 k +:ixvfrm2.snif 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. Then it goer3yg.boycxi9 : )b7sls around the same curve at half of the original speed. What is the centripetal)ylso:7ibc g3r . 9xby 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 v. Then k h q hznp*r//(68qioait goes around a curve of radius 2r at speed 2v. What is the ce rp6 h/a8znq(*i/oq khntripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes arot dlc03x(:modnw5 4u ) n8wkhwund a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizonwdc(80dhnuno4:wt5kxml3)w tal 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 s/gvm8h2ebzs+-er w m4ame angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radiuge 8m +24zrmhv-/ wbess curve is v. What is the safe speed on the larger radius curve?

  The banking angle in avij , w.vaje 27hox, u*iwj a4):reyvn88c* fj turn on the Olympic bobsled track is not constant, but increases upward from the horiuv4.aj c n8w*j:ri2 x w,7,heyv fv)8 oiejj*azontal. 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 objern:wsmx19hj k8p )m7hct moving around a circular path to have both centripetal and tangential accen98 7:hxr)pkm 1hjwsm leration?

  The gravitational force between two obje4)t hbt sdel;1pi:9bfxw 4 .lacts is proportional to

  The gravitational force between two objects is inversely prop m s qlah*d0;/f;ottz0zar 2*eortional to

  Two objects attract each other gravitationally. If the distang r6:h3 ztm0:yluhxd mss(;t 6ce between their centers is3(hm 6yrmu0ghsxzt6l: :;sd t cut in half, the gravitational force

  Two objects, with masses kmu+h y59z6p(3bvv *iql xns 8$m_{1}$ 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 masgcb8iihd2 76o.thv mm +1 7mreses $m_{1}$ 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 unives zxzn3x.z+ ) e9:;ug t/riefjrsal gravitation.

  Compared to its mass on the Earth, the 8si0psrk q/xo ,mo,*pmass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it*ql:vq qar 9qx1n6y-r is on Earth. An objectr rvly q9x q:a1q6*qn- 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's weiipc 8u,(:d mu/yge9 qight

  A spaceship is traveling to the Moon. At what*sn h jod(j;7bxculx .wdj0o:.kss3/ point is it beyond the pull of Earsd7c: ;/s.jh( xo3 k0 d*jsb jux.lonwth's gravity?

  Suppose a satellite v isj vg2ixo09d)84 :2df xrhy 5*yfdqwere orbiting the Earth just above the surface. What is its centripetal accelerat ): d5f290ig jryh8o vd42syqxfxidv*ion?

  A hypothetical planet has a mass of half that of the Ea mxyt)**n ll tpoet19;rth and a radius of twice that of the Earth. What is the accelet)*txlnlypt 1eo* 9 ;mration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixye,o8naw(zqbr)1pog8 fm; nx2lj2s,th what it is on Earth. The radius of thbs18pygxq,,(jow e2z )lm rn 8o;af2ne 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 pv-i )/-7 yp sd/:wnvc5vydxmklanet B has twice the radius of planet A. If planet A has -dd-/nixkmvv :)5 sy y7cp/vw mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass8.d,jqc(o+jc :i xf j20/td3 ikkyvtm of planet A. If planet A has radius r, what is the radius o f2i j,: (ciddkj3jk+/c8x ym t0t.oqvf planet B?

  Consider a small satellite moving in a circular orbit (radiusehy a/4i*uay7r;fas) r) about a spherical planet (mass M). Which expression gives this satea ry;af )eu4ya*h7si/llite's orbital velocity?

  Satellite A has twice thh0q/o *duc f: e8mbqk:l73qh( kg p9dhe mass of satellite B, and rotates in the same orbit. Compare the two satellite's speedmbo :k*k3hq: uh geq(79c 8dlqhp0d /fs.

  A person is standing on a scale in an g,-dlw w(8wyzelevator accelerating downward. Compare the reading on the scale to th( wdzgwy8l,- we person's true weight.

  Who was the first person to realize that the planets move in ellipt:f,i,dfc vq z8ical paths around the Sun?i,vzdf8 ,f:cq

  The speed of Halley's Comet, while traveling ib;nza5 q6)yo:2 ctboun its elliptical orbit around the Su)ot a:c5;oq2byb 6z nun,

  Let the average orbital radi6+cu( k) vtasy41unogjq l i*;,2hlohus of a planet be R. Let the orbital period be T. What quantity is cog u;l4c2+jakys)oh,v niu* hq(l 1t6onstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda1 q.gs1*uzs. th0drfy , 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 planetyu d sq11.*z g0tr.fsh be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomid4 lpnbn :.au(+msvn (cal unit" (AU). An asteroid orbits the Sun in one-third of a year. What is t.lp n bn:n4mv( du+sa(he asteroid's average distance from the Sun?

State Kepler's laws.j-(tu-yuqx2 pz wi;f(5ntkmlo; - 1zm

  List the four fundamental forces i tk lkd9lipb6 cg3cvo. )-n*0bn nature.

  An object moves with a constant speed of 30 m/s on a circular track ocho0 t:kxr,e 1f radius 150 m. What is:rek x1ht ,o0c the acceleration of the object?

  The maximum speed around a level cu.39h;wj ir6pg1e lfrhrve is 30.0 km/h. What is the maximum speed ar. rh1e;glifph3j9 w 6round a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration 4mvc3 *d6erqan k;sx: of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving eqx;3 *k mvnscd: ra468.0 m/s?

  A point on a wheel rotating at 5.00 re g v8967gbs4ch5 nzoapv/s is located 0.200 m from the axis. What is the cent nvb8 sz7p6chg94oga5ripetal acceleration?

  How many revolutions per minute must a circular, rotating span5sc mqifrg9nu)2--lz ( z5osce station of radius 1000 m rotate to produce an arts z5gslu2qc zr( )nfni5om -9-ificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass b4.5ol q67k1k:4c3l ejd hvj)jsarfl of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the e4a v.s7jlorjlj)fk 5 6 hb: l34qcd1kmotorcycle?

  A 0.50-kg mass is attached to the end of a 1.gaw6 i l0m-p3c0-m string. The system is whirled in a horizontal circular path. If the maxiaw06c3gl p-i mmum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strmje,(8m 7vlf75dd glrong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the s7mfrgl 7j5e8v(,dl mdtring 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 strongya szsdj (oa(f(4r *7k string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the strjs*y(doa(a74 s ( kzfring is 3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiencdrr/8+3 rh yxlkq1(jtzce q+: es an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyid31+l8eq c:rrjhz+r( x qt/ky ng?

  A pilot makes an outside vertical loop 1ri:f67bx nme 1fbqm 2(in which the center of the loop is beneath him) of radius 3200 m. At the top bq1n6 xi1m: femfbr72of 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. What is uz3i3dtgm/c 9ixx5i ;the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at amxx ugi;di953 i3tz c/ speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with t2 q.bua-gy g8dhe tires on the verge of slipping. How fast can this car round a sec u8aygdb-g.q 2ond curve 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 .o wxttym(6 yn.*cdb3with a speed of 20 m/s. The centripetal fobtt(.w3 com6y .xd *nyrce provided by friction 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 of 14 mr hn:7 vttls/c 04jz)e/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the4)z:e/ tcjt h lrvs0n7 turn?

  A car is moving with )zgss 3jaw f))a 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 razs) f)jw 3)gsoad?

  What minimum banking angle is required for an Olymps+iwy)2 r ,ggrb/cw0q j*bt)ys : py8cic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Iy,+ yj8giwrc0 )tsrsbp )c:wb2g yq*/gnore friction.)

  A horizontal curve on a bobsleddl u5kdcsl,-+ run 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 anj 01 3:wy :sm rcnveq.ok/lqm/ angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 vy jrv,g-v/su:gc5 y*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 nme6+ k;z d9 w1d7fqjtend of a string is revolving uniformly in a horizontal circle of rad1zf 6;nw7j ekm9+dtq 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 area, a race car yakf,sbk9*5 tjyf b21(2ki beaccelerates 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 in the blanks) j*k2ty5kybf,9 ib ba(2fs 1 ek
(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 ofo*;5e m)rls3zmsf 0iit j7x)h 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 aj(el5b ok6hwza c+6mt3;wqz 3 70-kg person standing on the Earth, due to the Moon? zc b+wmaj63wl ; e5o36zq(hkt 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 forc)kw0z+bbe/ zp e between two masses is F. If the masses are moved to half eb)z+bzwk/ 0 pof their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Suq+fv4)ow) q 0gvn+ sfzn, at what distance from the Earth will the grav4 qg+fz+o fvwnvq)s)0 itational 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 is n+sm3iqk2v m6 $7.4 \times 10^{22} \; kg$ 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 diiauc 8 .lz-m2fstance above the Earth equal to the radius of the Earth. What is her acceleration due to ga8 mz u.lc2-firavity?

  The radius of the Earth icz57y2 u mry78,ks gabs R. At what distance above the Earth's surface will the ,rb785g y yksucz7ma2acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above ;zt*,ji 7ofvzb+ 9qgyits 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 z i*v+ 79fby oj;gqtz,Mars, is

  At a distance of 14000 km from some ,y*m g5ygnf- v;mc(yfplanet's center, the acceleration of gravity g,g;cfym*m5nv y-f (yis $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on tw6- z(rhll puct1x1+ the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above c +wzll6 1uhttprx1 -(the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person changeqo 9p*,l.t/qf.+eql bv jyb;b when he goes from qqqp.bb *yf 9ot/vl.,eljb+;sea 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. Alfpm80j :3spi satellite of mass 100 kg is at a point 3r above the Earth's 0fj8pmpil:3 s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and t3o lup-8ub8 ,n1 d2wicg v7iqqwice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weiui,u3pwdqc 8gq 7lv1 8n-b2oigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same lineejgxnqkdd+*b2d+g* p04nb 1g, with the Earth between the Moon and the Sun*1+b2ekn qj d*4pggbdx g+ 0nd. 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 isxdjf ,ny8bka2w z08m/h-8p n b transported 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 aboupj3 zkt i/(am)jc) ;qjt the Earth (i.e., it just skims the surface of the Earth). What is the ja tj)z/;k3c )qim(pj speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a cyupx2b zi4x: 7.8ohplow circular orbit about the Earth (i.e., it just skims the surface of 2p4uz.7x io:x8cbhpythe Earth). How 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 Earth. 3,qh-, i48p emzow mdr It is observed to have a period of 89 min. What 3hz em -o8,r,p 4dmqwiis 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 dfa w(pxf.ijth/ i5 )t)iameter 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 qnk)krc;j-ze )z7dk.e34dppttd 37 t 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 circf0) 38yb(iejz6m nq8n e s7ahqular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon q8 ( nn3ze8)shf7bmy qij0ea6 A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isx3wa;j/pj/ skhd n5ir4 ok7q 3 $7.78 \times 10^{11} \; m$ 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 once. What is;jqk( s:bp dr/xi7ky* the average distance rpi ;j*d (xbq/sky7k :from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)