Is it possible for arg3 ke)n )yoly41lhb4n object moving with a constant speed to accelerate? Explaino)yl 4h )kgbny 3lr14e.

  Consider a particle moving with constant speed such that its accel9+nrwpk0syu7 kn 9a t7eration of constant magnitude is always perpendicular to its +7 t7uy0p9 wnk9knasrvelocity.

  An object moves in a circular path at a constant speed. Compare the direction oq(kx, g+i0cyh mcnng /nwnc 1 fo-y/1:f the object's velocity and accelng fgc10yn/yx,kcmo/wcn- h1i:+n q(eration vectors.

  When an object experiences uniform circular motion, the direction of the accel. st+v2d3feepbb(z 5mq u)l2 oerat+d.bb qf5opsuv2 l )t(z 2e3meion is

  Consider a particle moving with constant speed such that*rxv ) 8k*qdpl its acceleration of constant magnitude is always pdlk*qv)r8 px *erpendicular to its velocity.

  What type of acceleration does an object moving with constan:np;n *ndb -- zymvay3t speed in a circular path experinn a n3 v;z-d-b:y*ympence?

  What force is needed to make an object move k91 9t1 ytrb7h y/8cs:uizq bt i-dz3hin a circle?

  When an object experience 5alz. 1mcznp su;ud59s uniform circular motion, the direction of the net force i 9 ns5zamc.l;upu1zd5s

  A roller coaster car is on a track thato zr pyi+98)f- 2ygksd forms 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 for its centripetal ar )dypg 2y8s+kf9o-iz cceleration at this point?

  A roller coaster car (mass = M) is on a t (uzpnjq;ua9fg41- nvrack 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 that point-z fgj nu(1v;n9u a4pq?

  A pilot executes a vertical dive then follows a semi-circular4770hr ,zqvkx yh0r 7plwr wl5 arc until it is going straight up. Just as the plane is at it7x0hr4 0p7z, 7lyqwl v wrhkr5s 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 fix*u73ofz(bxv) z -fradius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of ecj,a)xfw 6e7radius r at a constant 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 goes around the curve for the second tiaxj67, e)efcwme, compared to the first time?

  A car goes around a enb ,rb4 ohi)*4turtimp:u f+:3 r n.jcurve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speerrbirt4)hfujtn.bu pim +: 43n:* o,ed 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 bazrd; mdz( /naf4r5 q/enked curve of radius r with speed v. If the road is frictionless due to ice, the car df z/n4ae(rz/r qd5 m;can 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 m-h9g gs4bj:g angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the m4g9-hggb:js 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 cz v3jv; 0pt3j;3rsjhis not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall,zt; r;30j pvs3jc3hjv " 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 xvwicwqk0*9x l *g(+ohave both centripetal and tangential accev(lxx o w ckgiq+*0*w9leration?

  The gravitational fod3 )l 4:wrlougrce between two objects is proportional to

  The gravitational force between two objects is invir of1d,* cxs0 6dn:rkersely proportional to

  Two objects attract each other gravitationally. If the y0r/xc6 3lnnr distance between their centers is cut in half, the gravitational rrnl y6/c0n3xforce

  Two objects, with massesv qjw:t24u+37 7arz 0rat tabq $m_{1}$ 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 massekjc en7 d9 qm6iq, 891aydqv+es $m_{1}$ 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 unu1xtmma.t q (6jp 4xu8iversal gravitation.

  Compared to its mass on th*1( z2jfh f2rwqr 3(0kioosogy rn 0e1e Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Mo g1u)alxw6 hc;on is one-sixth what it is on Earth. An object of masxug )16l;hawc s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Ea lh)8af tn+s3nwa9*xlrth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull wzp );d8e k.1gyvpk xf c4m*m7of Earf ) g8.kvwm pexm*1pk; cyz4d7th's gravity?

  Suppose a satellite were orbiting the Earth just above the surfa2j4,rqc kredjx;1am* ce. What is its c m2dqj,1rrkj;ec *4 axentripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and04e *md8mqrug.jm: um -x f/dw9ou6si a radius of twice that of the Earthsuw6 emfdm 9g8.m/-u0i*r4 doq: jxmu. 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 on the Mo 2 q/did+:ero+5 b*mrbjg gr+*q1cvqn lf 5n4aon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. q 4ib+5nrcoedanm5v+b2g:j/ q1 * rqr* fl+ dgWhat is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twic9 etldv bgj /by4n2j71 d;teo6e the radius of planet A.dd j6y;2 glo1t7vne 9ebj b4t/ If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the maskup r0q12.xc3j8 ut bdy.qys-s of planet A. If planet A.qu-uy.82xrtkcsq0j1bp d 3y has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orgl:h8-rt o ;5g,zyvk gbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital veloc- ;,g glhtk:ovg5z8ry ity?

  Satellite A has twice the mass of.uz5t rrr,yaig99 u5k/g8c7di ;msmi bw 4fc) satellite B, and rotates in the same orbit. Comr7ig.u9) rb gm, 5yicrz5adk 98ms u4itcf/w;pare the two satellite's speeds.

  A person is standing on a scale in an elevu- ow 8 ruu1 y)q6n4eaie0nj.hator accelerating downward. Compare the readin.nr)uu0q6j h841euoaw y nei- g on the scale to the person's true weight.

  Who was the first person to realize that tha uzkvt4w ;8k l64:xu8 +jtdvc ui66whe planets move in elliptical paths around t4 julcahv4kiv68 u:uwwzt 68 xt;d+6khe Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit arouubos t f(a(i *7mz(8-bwax(a end the Sun,bw(am(s fa(8-b zitxo e ua(7*

  Let the average orbital radius of a planet be R. Let the orbital p b 3xvhru8wf1-eriod be T. What quantity is constant for all planets orbiting the Sun? 1hurvf-3wb x8

  A planet is discovered to orbit around a star in the galaxy Andromeda, with . bg)q q 66)ijqukni3tthe 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, compared to the Earth's orbital period?u. qqj6bqnki) )i 63gt

  The average distance from thycu 4 8r. gpg5+rc),t-vpcj lqe Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a yearyglgcu54r )r+jqppctc, -8 .v. What is the asteroid's average distance from the Sun?

State Kepler's laws. pln2uhoj,1+3faghp 4

  List the four fundamental forcesb db.1n3ons)bfr52 k e)wore 3 in nature.

  An object moves with a constantylglu0v +2 8(kv6q)qvjm /aqw speed of 30 m/s on a circular track of radius 150 m.uq+q0)vlva vq 6jl8(k2 y/wgm What is the acceleration of the object?

  The maximum speed arouiyd no8* fl8r.nd a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain u8yn f*r8i.l donchanged.)

  What is the centripetal acceleration of a point on the perimeter ofx2ed(lkyqhy2ys,/olmw9 : p- a bicycle wheel of diameter 70 o ,l( hydp/2sxq9-lm: 2y wekycm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00*3 e0dx htkft8;m/yi g rev/s is located 0.200 m from the axis. What is the centripetaxk0 ;m8* g hde3ytitf/l acceleration?

  How many revolutions per 9osj 67xn xq+(+d6a z5 b-hevwb vtvm,minute must a circular, rotating space station of radius 1000 m rotated-x bv+,6 6o7(jvx9vzew5nst+bhm qa to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass fxsu/ 7b*;tr krrf 6u)of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetalr6x/r) r bfst;*ku7 uf force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system iaal h(ts6 (4rmv 58ehys whirled in a horizona 4vl5h rt6a (ehsm(y8tal 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 break?

  A stone, of mass m, is attached to a ste er, zdik d*4t7 m2r+n0(lshnrong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stom 4dht2+ e(s kznr 07nd*erli,ne's speed at this point is given by

  A stone, of mass m, is attachedfv y*n4f yj15o to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension f*jy5nof41vy 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 accelej (a*q. omgr(8 iyyh9vration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyiamyo iv.g9(( q8hr* yjng?

  A pilot makes an outside vertical loop (in which the center of the loop ip,(0,nsk q so3v: 2r dtrmu9qps beneath him) of radius 3200 m. At the top of his loop he is pushing down on hiq0sd,q ( rv9mpso 3pturn 2:,ks seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is( qhvdzrg p(m:jiqd(/8d -g8 y about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of: 8g(v(qmi 8-jzyp d(/dqdrh g a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rw+wk j z f ,i*e6-adtt6 nmr8r6fi+c*counds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radi*t,wraczmtw-r*cfik6d6+j e68 f i+n us 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 with a6,yk ,cb+z 4bloo vi/w speed of 20 m/s. The centripebo4il bc,w 6+o yvkz/,tal force 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 mt7*z +q kpqcq2/s. What must be the minimum coefficient of friction qpt*cq+z 7q k2between the tires and the road for the car to make the turn?

  A car is moving with a constant spee5bpt /,dzbcmm y x2/d0d v around a level curve. The coefficient of friction between the tires and the road is 0.40. Whmyx2/p/0cm5d bdztb,at is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is rep xufr1gh (d/1quired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s (pux1h1dgr /fwithout skidding? (Ignore friction.)

  A horizontal curve on a bobsled ru.4 odhjk*6qjbn 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 rad1 (fm ;o.gagjwius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banke5+) ,d nzliklyd 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 horizont 8a yszh0jwd5p y xi. /nk4-ekw9f5tffi3 3sq-al circle of radius 0.5sh3nsw5iypij-4/0 x- wdfayk 5z.9q3fke 8ft00
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:8r .ywzc 4 y-:xeutie rh5:yuates 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 numeric u :cxwez:hury-:t48ery5iy .al 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 conk2ntvb3 zhkvb : 8e.v2sists 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 Earth-lafkqt8/7:yn km4f a , due to the M4f matn kyfaq8k- 7l:/oon? 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 masses is Fo 5zfv x 0*l:cvxt:6uqd6 ayj0. If the masses are moved to half of their0*oa:tzxfvclud:j6x 6v y q5 0 initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towarhyx*rk3hr2 v8nww +2rd the Sun, at what distance from the Earth h2v r w 3n*r8khxry+w2will 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 isdr,q) 9wu m;hswhbwv mp)9w-6 $7.4 \times 10^{22} \; kg$ 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 distance above the Eoljuh4q8/.oy8fc s 1oarth equal to the radius of the Earth. Whauooo ys8/81cjqhf.4l t is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's sukym hw 4l/b48*yuiga tazo*6 ,9 rb/mbrface will the acceleration of grav,myb9ozlr 468 hy*k t*/mgwba ub4a/iity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 tva4ybf,l k lcwo //8u,imes the radius of Mars. The acceleration of gravity of the satellite, as cow/k auyvbflo/4l,,8c mpared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km-i sqit v0kk,* fo7x+m from some planet's center, the acceleration of gravity is * ii0f k7- tkmxq,so+v$32 \; m/s^2$. 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. hn+6+: gvkuykThe Earth has radius r. If the obv+h6 ygk u+k:nject is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weig;/ -bcrj/iti 9eziec:ht of a 100-kg person change when he goes from sea level to an altitude of 5000 m;e brii-/ cje/ 9tz:ci? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of zwaf5 +anq, lx1pe i90pv2jt) mass 100 kg is at a point 3r above the Earth's su t a19v0p2pweniqjx, z)lf+5arface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and t,u7r1h 4fw( dcdu8z5zsh fk9 vwice its radius. If a jar of peanut butter weighs 12 N on hsdv uf5wd 41cf z7r8u, 9hzk(the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Mo(e:k+fxlcws9 on, Earth, and Sun all lie on the same line, with the Earth between the lc 9wsf ekx:+(Moon and the 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 otsh7y4 j 8oersw**: tis 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 ab*8mfm6thd-m*o3 9 c zok( shlaout the Earth (i.e., it just skims the surface of the Earth). What is the speed of the sak3*oh *mfzdo-ta msl(h69 8mctellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Ear7q q1i3a.t )xer,ebw sth (i.e., it just skims the surface of the Earth)ee7r)i, .q3 xwq1at sb. 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. It ;1 im/fj.tp lvt3v:gxis observed to have a period of 89 min. What is thl;f t3 1p.i:m/vg tjvxe 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 diameter of4z0rjr5*k seo2p.hv- b m p)tp $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a radiu tprd9f l8b9:fs 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 orbi*ctc4twor9v w :qbh,y )8xf o .(xi+wdtal radius r, and moon B hat x 49x+yv:c,d q) i.hcwt rfo(*wo8bws 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 in.uzpq3+opn*ehy2ymj+g,y 3nj s73n s $7.78 \times 10^{11} \; m$ 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*,gi hgsbw6:;qgdv6 z 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance s:,g6 vq;dbghz*6igw from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)