Is it possible for an object moving with a constant speed to act8 tm; wvaz52irbl.9 jcelerate? Explain 8;92 i.mjtztblwr5a v.

  Consider a particle movqbq-;6, get )ck wwi*l8 sblh;ing with constant speed such that its acceleration of constant magnitude is always perlkcw; hwt6q )i*b,l-8 ;sgqebpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare th5ne8yna7vcti p1h8 9n* ;d rvle direction of the object's velocity and accelerati7ri5v*ph l;y v8end1an nt9 c8on vectors.

  When an object experiences uniform circular motion, theu*-hid vq8 )pxz8u4wr direction of the acceleration i xwzhq 48pvd8ur-ui*) s

  Consider a particle moving wp+ rh p--nj5k)au;)6icysfegkcj :n-ith constant speed such that its acceleration of constant magnitude is always perpendicular tgns y hr-5c :pjkpu ke)n6)-j;c- fia+o its velocity.

  What type of acceleration does an object movi3sg6g -l pzye2/m+eod/jl9 rdng with constant speed in a circular path experience?l ljmrgeg 9e 6/yd2z-o+ps3/d

  What force is needed s9 v19q 7rjj 0mo7(p1ygumo i1cn0i6m9h upgjto make an object move in a circle?

  When an object experiences uniform circufl 9;s1h+l6p e(doe yalar motion, the direction of the net forcee fl ao6+9hs(ylp;e1 d is

  A roller coaster car is on a track that forddq3 c ebtm4w *m78l.sms 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 centri s3me8dltdb .w47qm c*petal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (radiusazg g(d*mbi ,cv0 *a8v = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, wvi z( 8a,*gvd*g0bcma hat is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc uw ri,;p+h7gumi4h+ x until it is going straight up. Just as the plane is at its lowest point, the for+p hxg4 uw+m;ir u,7hice 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 q6s-xbf:vp 8v (hpxm 3radius $r$ 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 goes aroqheq2qt41rmwv 0: my ef4r v+c2 (06gkbrv-gmund the same curve at half of the original speed. What is 6g:qgvm2v fb r1hq04eqv wy2em4 tr-m(+ckr 0the 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 v. Then it gzwpp( k s57ur,oes around a curve of radius 2r at speed 2v. What is the centripetal force on the car ,p k uszr5pw7(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 o.:wh2wtcij+ v. If the road is frictionless due to ice, the car can still negotiate the w c.jhi+to:2wcurve 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 ixa37+r8wpl me c oha3t8fw22 at the 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 radius7 f2+3x oa838ewpclharw tim2 curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic(k f 8ydz.cb4f bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wzkbc fd.48( fyall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular p;5tsx)6 ero n px7yn97v775bsealm rwath to have both centripem76to 5nv br ;5)wxenlp9sa7 er7xys7tal and tangential acceleration?

  The gravitational force between two objects is proportin aysc bp*;etdy p7xer94* 1c(onal to

  The gravitational force between two objects is inversely proporl, s4s-,6jrfv ajy ntp dh0;a-jrm+0f tional to

  Two objects attract each other gra*t:vz,gqn-zj9z a:sz vitationally. If the distance between their centers is cut in haz9zqz:z,n:-ta* v gsj lf, the gravitational force

  Two objects, with ma6 q9al/jnubh)e n8*fv sses $m_{1}$ 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-gehct 5u ng/0jbg55u $m_{1}$ 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 oylpy py6:r (bdj-xi52f universal gravitation.

  Compared to its mass on the y.a,p/1njetjn . jnv( Earth, the mass of an object on the Moon is

  The acceleration of gravity on tve,c/w4.-a e5 x4hli s5oqwxwhe Moon is one-sixth what it is on Earth. An object of mas4h45/-5 xceov e sqw,axlwi.ws
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away frhv dg+ /ddwtcs(w(b- 3om the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. bi 3wq,-ut:neAt what point is it beyond the pull of Ea nw,3-uebi :qtrth's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Whmiaoks (-x2lnv u/)j1at is its centripetal ac/mli v-kjno(u x2a)s 1celeration?

  A hypothetical planet has a mass of half that of the Earth and a rad5aowdw8pc1//(fkk woy( gaa k6sgk ze +32tm4ius of twice that of the Eara s/ kyf(z+tk(23gwakka5m8w c4g/ o op1we6d th. 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 Moon is one-six zx;.sj/e+e ,tp c5imeth what it is on Earth. The radius of the Moon et +ejm xz;p.s/ei 5,cis one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the ss6r jdq h,erp43oh(n:ame surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of plar4: nshj hq6d,rpe3(onet B?

  Two planets have the sa*tyq.zafw)fsy/464o ujt 2ql- h a zo)me surface gravity, but planet B has twice the mass of planet A. If planet A has rad*2la z.wts4o/ q6q-ohzju yfayt))f4 ius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a + cl(+kbna:o+zf rjg1i (+ hulspherical planet (mas k rhfczl+ :n(+ao+l(g+ bji1us M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates i xoo tlu: 4)yx e z1gvcj4-zskdr4;j08n the same orbit. Compare the two satelod j0 j1)so 4eulrv t-y44kz:c; 8xgzxlite's speeds.

  A person is standing on a scale in an elevator accelerating downward. C;vqp0 f. xcd9qompare the reading on the s fq xp.dc0q;9vcale to the person's true weight.

  Who was the first person to realize that the planets m;- gvudfegg,p rs309eove in elliptical paths around f9gegv;ru e3gs-,p0 dthe Sun?

  The speed of Halley's C: ) q5x7x4dxzcw1bl7 v7kcdex omet, while traveling in its elliptical orbit around the Sunb:cq7k4 x7x x)zcldewdx7v1 5,

  Let the average orbital,8z w tlj(r/ cbpbl5b5 radius of a planet be R. Let the orbital period be T. What quantity is constantl,(pl58b brzjbct5 /w for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the ga2 46ua 3r(scen-qzcev;8ci 5zl5q tx plaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star ia pc3cz; lqs5-r6ue(2 4cqx ven5t z8has 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 fromhg5rc,6kkiw;q)iory o; g e7(x:h g /a the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from iohh/x76,g(qirgw 5ky;c kora g:)e ;the Sun?

State Kepler's laws. qg,-n 5x9n.5vczy awk

  List the four fundamentalk gy3 t2ne2q3o forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiu1j3 (8domhqdj s 150 m. What is the acceleratiod3jhqjo8 ( d1mn of the object?

  The maximum speed around a level curve is 30.0 km/h. What 9v)ta uv 5 p)lg l;j+zn3:cauuz 07lnais the maximum speed around a curve with twice the radius? (Assume all other factors73u0nul 5+z:;vlz)nlvpga9auc) t aj remain unchanged.)

  What is the centripetal acceleration ox8tldq8rd3uo 5j 6l :yf a point on the perimeter of a bicycle wheel of diameter 70 cm t 3y6 l:xj58udqrdl8owhen 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 thonwy / j eq2(wf7teu11e axis. What 1 nf /72jqoe1uewtw(yis the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of radifaoia ,bh89z 2q z6.s8hhs2zkus 1000 m rotate to produce an art kohz8h9,qbz. 26a f82azh ssiificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goess3qfbelo ofhd 7o(33ro -t/1 y around a 13.7 m radius turn at 96.5 km/h. What is the centripetal r3- oo1/ ffdyqtolbs3( oh e73force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is wnvwk2cp q /w.; ,-cek+)nddlrhirled in a horizontal circular path.;ncpqnd d, wwvr .c)kl/-2ke+ 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 strong string and whirled in a veuww ,x..n/za vtb:mi+ rtical circle of 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 give +x/t n,:ab..mwv zuwin by

  A stone, of mass m, is attached to a strong string aqsrl. 7 b5 wu5aji+8x:// bplc a.yrfjnd 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 speed atpa.l /crbu8iq jr .:j5la5/ybs7 +wxf this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulli. ;izlah4 p4 1uhv:h4ttuh t+rng out of the dive. What is the radius of curvature of the loop in w1hhau thlirp vh44+ z.4tu:;thich the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is ben5 f/p.drdkw +ueath him) of radius 3200 m. At the top of5 urp f+.kdwd/ 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 aboul28lkt8d 8wmvmeio 1rx:c +:bt seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling ommw 2 1t8x:l8lori8+e kd: bcvut of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radiun1., akbb/kxh s horizontal 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 an b,kbk.x1 h/tires and each road surface.)

  A car is negotiating a flat curve ta1 cv (un qjyx49f-z*of radius 50 m with a speed of 20 m/s. The centripetal force provided by frict(qz 1-fv9 n4y ujx*tcaion 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 m/s. Wha enaaew2q*eg10m)/kip8gc (w 5blh:st must be the minimum coefficient of friction between the tires andegwicql( )wee1k gm*0nh :/ apas5 b82 the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. 4wo/xr ;y s5 ai)piz ,wt5w7ztThe 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 tx5awzwrtty; io/ is p,z) 7w54he road?

  What minimum banking angle is required for an Olympic bobsled tj5bapja . w/k* 5)p.wai7ipa.gidk c iu;+ 1uyo negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore5ap7di p auwi jk w)ap..k5+/gb*ii jy;ac u1. friction.)

  A horizontal curve on a bobsled run is bankedr 7;b be4hed:g 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 anglel 6 yuyt/e*uu3v; pvy0 of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at q4 ,ubw +slf)88nte kj$45^{\circ}$. 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 uniforya7w8g zl-c 5z7ugj4 emly in a horizontal circle of 7-gjzw485a z yc7luge 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 area, a race car accelerates x p4/w:,eqf y-ym2*ex2 k ngsgat a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track ewy-n:p4xksx/2 fq* my ,g2eg 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 ou1v 4lrkp0ba+ h t(ja:f 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 gravitatiy lzmuzv2+ pmp;w* z)7onal force on a 70-kg person standing on the Earth, due to thu)z*m pz +7wv2 mzpyl;e Moon? 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 beto. ;v.a2edl hbween two masses is F. If the masses are moved to half of their initiedvba.hl2. ;oal distance, what is the gravitational attractive force?

  For a spacecraft going from the Earj7r7 er.do+ 5u; v vnw:fl2qafth toward the Sun, at what distance from the Earth will the gravitational forces due to the u.7j f:rd+lovf7 aqv enr;5w2Sun 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/j a9,/ydrdkl $7.4 \times 10^{22} \; kg$ 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 Earth e2c* hueu omx-1qual to the radius of the Earth. What is her acc1 u2hcu m*-oxeeleration due to gravity?

  The radius of the Earth is R. At what distav7gzuk q .z, .2zwl1wznce above the Earth's surface will the accelel zqgwk12 zzu7.w ,zv.ration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface v3z zr gm.5x woiq-+mv*4c)yn equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the i)ovm+-c3 xyg m*.zrvnw54qzsurface of Mars, is

  At a distance of 14000 km from some planet'td+n 3-hnmu1n 6r -mtpkdc8 5ks center, the acceleration of gravity is5+1-3t hcn6k dm8u nnrtpk-dm $32 \; m/s^2$. 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 Earth has ra ;4v5zbw1 ija-drkf 3idius r. If the object is raised to i b3wr 1 kvi5jfzd;-a4a 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 he goesqk4rnqtk6iw96ie c /9 from sea leve4t6wnck 9iki69 qr/ qel 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 kg is at a point o;)9za yhe7 iiffvn .(hy p(m(7r2zwjwlb( q.3r above the Earth's surface. What if zrviay77 b hye q.n .9(p(2( (loz;fjmhw)wis the satellite's weight?

  A spherically symmetr a hn3 m6v*st,.fxrk(aic planet has four times the Earth's mass and twice its radius. If a jar of peanut buttehfm a,rk*x3n6a. s(vtr 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 o /5y c7v0ygm1o+mjxjzax1*s vn the same line, with the Esx maj5y jmczg0x v oy*v1+/71arth between the 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 is tra2(sgrk ysb zi5pe/v. (nsported 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 the Earth3 h0l7bwc(a cx (i.e., it just skims the surface of the Earth)0cwx( h7lcba 3. 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 low qu ; klv4evzslx.:guc5c f(,/circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to mle/ l;u.s vz(vk,5cfc gx:q4 uake 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 rpo)syb/5i; wof the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth iso5 biy)p;/wrs $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamet *-gdb4u:4lk1ef ; wu(/jsu y nta8qz8nfp/gqer 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 npw paq1.uxer)/ q*0xa 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 o5.dzbe0f 0a-o vsinw5rbital radius r, a0n0b avd5.e-wfz5 iosnd moon B has 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 is +f*eth , by:go$7.78 \times 10^{11} \; m$ 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 the average cs3(2 xeno9txdistance from Jupitero3x e9csx(tn 2 to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)