Is it possible for aneqk1m+vjb y5 -y+sw g3 object moving with a constant speed to accelerate? Explai1j+eqb s k-v wy53+gymn.

  Consider a particle moving with constant speed such that its acceleration of coki8j3 p(b o rvib682klnstant magnitude is always perpendicular tok8ii83 bvbrlpo j62(k its velocity.

  An object moves in a cik*39uczg4. ega1awc w rcular path at a constant speed. Compare the direction of the object's velocity and accelg 13wu.cwa9*czk gea4 eration vectors.

  When an object experiences uniform circular motion, the div9l*pmi nh)( 7zs ,nnkrection of the accelei nvls)km,7 9n*hnpz(ration is

  Consider a particle moving with constant speedkmpe3hou 3adch)5 z5v7/ g2bi such that its acceleration of constant magnitude is always perpendicular to its veloma uz i3o/d e7h5bk)c3h2 5pvgcity.

  What type of acceleration does an s mfa-)b i3qpf,e:*3u;v bhmx object moving with constant speed in a circular path experience q,s:mvf 3-xmuphba)f *3eb; i?

  What force is needed to make an ob4jc+be09 rkk qam8bzz9 ;m8twject move in a circle?

  When an object experiences uniform cirtfx5 i,.jro k2w:0lhn y9f h4ncular motion, the direction of the net force is2kfjh4xfi n0,9ohln5tw :r.y

  A roller coaster car is on a track that forms a circular lo p:t-i- cz:fmurc4ny*:4v dh rop in the vertical plane. If the cary4r -*iv :tm cdu4 :chzrn:pf- is 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 (9/yhxrmfx.x 5 mass = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just mainxy5 xf/hxm9. rtain contact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a v(d sgkgv6a .n1ertical dive then follows a semi-circular arc until it is going straight up. Just as the pg(sav6g1d.k n lane 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 cu u2q 0j;44 r/o8, :egrml fveiimp:2os siewj,rve 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. Then it goes arlik-s4zww. soe8 r..kooqt) lyvi./4mycs (,ound 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 time,t) w.s,liyi.- yk8(s 4q/.4v ozrokew.mlcso compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it go :;hfuyj.r vz+es around a curve of radius 2r at speed 2v. What u:z vjr+;.hfyis 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 rg qmakqd2d--k; ns8.gadius r with speed v. If the road is frictionless due to ice, the car can stillngagk8-d q-q2m. dsk; 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 bankg:s y+r6 gt*i;*hhx lmed at the same angle, but one has twice t+grmxg yl s* 6hti:;h*he 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 curve?

  The banking angle in a uoewa2/pn ;n9turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, th 92;waop/n uene 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 circular path to have bosffuymage* ,c 9e ,z/0th centripeta*sc,eu 9f,me /gfz0a yl and tangential acceleration?

  The gravitational force between t20mg9 c m g:2s0 noqga/r*fyuhwo objects is proportional to

  The gravitational force between tia 5ll 8*xd x8.oduhc jl7o3d*wo objects is inversely proportional to

  Two objects attract each other gravitationally6jum9l*p+6g:ja*rael /h ivw; 9eyk n. If the distance between their centers is cut in half, the gravitational forlha*rpe* g;+jm k9j6ev /6uln:i aw 9yce

  Two objects, with mas:0o ge eaac.7sses $m_{1}$ 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 masseb 3snis+ljw c)a4k. 4ps $m_{1}$ 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 uni7gy1gpl-x0nzfj.z yvw k+ :)gversal gravitation.

  Compared to its mass on the Earth, the mass of an ob,e2mfqwjxt1t 8;*thn ject on the Moon is

  The acceleration of gr cdtmqve0at)s16v4kc k s4f i(c6 3l/ravity on the Moon is one-sixth what it is on Earth. An object ot mv1v/t3d qlca ( 4ksks40fcc eri66)f 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) v1,lpdk qf(b2l.n-jt3/ pnobp7p usq8 xab9's weight

  A spaceship is traveling to the Moon. At qsphtoj ,3/,spj5*gasri 6 o3 what point is it beyond the pull of Earth's gravit53/ s ,sa3jpqiho*osg6jp ,rt y?

  Suppose a satellite were 8 euuu;r- 5l5 ol3fc-ht8piqcorbiting the Earth just above the surface. What is its cent5eoqf8 u53l8u;-lru ci hcp-tripetal acceleration?

  A hypothetical planet has a mass of hahzjg4f ot()0nu;wa p5lf that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planeg p40z)u 5 tjnahwof;(t in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. Th7zniyg/ cdv:/ e radius of the Moon is one-fourth that of the Earth. What is the Moon/gy7i n/v z:dc's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has t 4tx*ae0n3ticwice the radius of planet A. If planet n3cetit04 ax *A has mass m, what is the mass of planet B?

  Two planets have the same surface gravit/clbs (pzo185kj np)z y, but planet B has twice the mass of planet A. If planet A has radius r, what is the radiuj )1zklnocps(pz/ b 58s of planet B?

  Consider a small satell5j44g5oke/ayu tex h ;ite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orb /a4gx4ek55yuj oh;te ital velocity?

  Satellite A has twice the 7l uma. qu+etls9m8+ smass of satellite B, and rotates in the same orbit. Compare the 8slsem7utl.qaum 9++ two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downwmgds ,7 /8 /fvmimu5fnard. Compare the reading on the scale to the person's true weighgmsvumn 5 /m8f,d7i /ft.

  Who was the first person to realize that the planets movey yszt uleit-ow/cr8 18))/j t in elliptical paths around the e/ jitz/8t-utwy r8s1ylo )c) Sun?

  The speed of Halley's Comet, while traveling in i)/my 7 da3lbkhts elliptical orbit around the Su7 kmh)y/ab dl3n,

  Let the average orbital :uio4m pli+6 v :d6dtbradius of a planet be R. Let the orbital period be T. Whib 6i +tp: :46modvlduat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit aroer,uroerk 426 .gpw ,lund a star in the galaxy Andromeda, with the same orbital diame r,g e,rlwe4o2.ku rp6ter 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 sbwrnu/1no6868. zh k/0yqmi qbu6cuthe Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a 1rchm qu6/.sn86z u b 8/ kuwonb6i0yqyear. What is the asteroid's average distance from the Sun?

State Kepler's laws.p0)am6ge d,0tlm*des

  List the four fundamental forces in natuimk 3jxy3b9wi 8m5wie//:x ;6sfjx hu 4-fumhre.

  An object moves with a constant speed w0bf y26 rou6zof 30 m/s on a circular track of radius 150 m. Wha frz uo6wby602t is the acceleration of the object?

  The maximum speed around a level curve fu 2wtl/3j:y.6enm js is 30.0 km/h. What is the maximum speed around a curve with twice the radius?.3uen tm:y/f 6wljj 2s (Assume all other factors remain unchanged.)

  What is the centripetay ,m) 1qd:ecamqx8,wn l acceleration of a point on the perimeter of a bicycle whqdq:mx)nc a1 my8ew,,eel 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 0.20k6xkoamvqt1d..nx 5+ 0 m from the axis. What i 1.5x6dov .+xnkak mqts the centripetal acceleration?

  How many revolutions per minute must a circular, rotating sp4ki xp4r bbepn,)/nsy b*;k /pace station of radius 1000 m rotate to produce an arti;ikp,4ypr b)bsxbn 4*n //pekficial 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 9(24vv7ent 9-jyfr;d qdt)xcb 6.5 km/h. What is the centripetal force ;2dtcdet-vqr)jn b 4(9fy7x von the motorcycle?

  A 0.50-kg mass is attached to the eg*w,5 .1.c: r 9drofqebmaquwz0 x0pwnd of a 1.0-m string. The system is whirled in ac9qpwd*.e mx5 g0a, fuq0b wrz .:rw1o 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 break?

  A stone, of mass m, is attached to a strong string and e *ig7vva0vb fr)v8e9)hgxse ce34g) 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 stone's sp bg*c48vv xavr0hg e9gefie)3)ve)s 7eed at this point is given by

  A stone, of mass m, is attached to a str chs vtpb(i5+c765rsbjf+ is(ong string and whirled in a vertical circle of radius r. At the exact bottoscv ts6 ( ii(j5h+b 7c+s5rbfpm 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 jet plane flying 600 m/s experiences an acceleqey*b+jp/*gl/bhch 8o c v2-v ration of 4g when pulling out of the dive. What is the radius of curv vg2by b*8v-c +lqh*j e/cop/hature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the s-4d i 50ea.pap(u)esgj c.um 8ad8bqcenter of the loop is beneath him) of ra5mu (a0eudajpc 8d-q4g8pbsi.s )ae.dius 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 going?

  The maximum force a pilot can stand is about seven times his weight. W j; r-6zcioi( txs-v8lhat is the minimum radius of curvature that 68t zcioxl j- si-r;v(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 horizontfo nxgjm8 frvji (t4;w*:;1nfj6w+eo+g mbx*al 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 t g *mw o+;x6( rfxnj:ojfib4ng;m1w8fjv+e*t he car's tires and each road surface.)

  A car is negotiating a 2yrjca)aq2n5 /)h.pf iaf9at flat curve of radius 50 m with a speed of 20 m/s. The centripetal force proic).f/ta n2rh pq9)2fayja 5avided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of rfq8,3 ,wg kmntadius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road fo fk,wg,q m3nt8r the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coefficien m jupn:n1d9jn7olws2j +/ 9vwt of f2lpvdjs 1wnjn+n99owj:u 7m /riction 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 road?

  What minimum banking angle is required for an Olympic bobsled to neg+x/smta 8f i8lotiate a 100-m radius turn at 35 m/s without stfxa+m l8/8i skidding? (Ignore friction.)

  A horizontal curve on/ 6bx7tgj+nf0gj3oxb*z dr * r a bobsled 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 100x, g ecgxg2 7jwng4e4, m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedwmoan 7d4u w)o4d1fwk (xzm yb;*s 1-t 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 uniformoyi;xo h0 fo 86ayd sybw9r-1,ly in a horizontal circsaybyo-1o,; 096 doy8firwh xle 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 area, a race car accelerates at a uniform4bg6 al8p mz; ct) obke*q2vnr6rj*r ) rate to a speed of 45 m/s in 1r4kbb6zj 2)t6 ora 8v; *clgnq*pe)mr5 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 98vyj c7g0/i9qr/ yupg5 ;asb(jjpei 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 0ombtb4pb +f6q2) cj vforce on a 70-kg person standing on the Earth, due to the Moon? The mp0btofbm 2 v)cb q64+jass 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 F. , vbl.ctom3s1ll 7e+ackl38gIf the masses are moved to half of their initial distance, what is the gravitational attrac1 3v.c3s7ll ,a +kotge bclml8tive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from td )ep(7q bn(wcg nh52; odlfo1he Earth will the grav 52 efohlc(b)dng1wqn;7(pd o 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 up6(dlpg8ic*3au0iftn v6q7 $7.4 \times 10^{22} \; kg$ 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 "*h g myx2g;5hhspace-walk" at a distance above the Earth equal to the radiuhx2 ymg5hhg *;s of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's :utn hx/r8.d6goy3 3 ju ozz:fsurface will the a.oho3u/uz68rxz :3t j :dgf yncceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 zooza 0u:il 3;tqz0ns*tfx80 times the radius of Mars. The acceleration of gravity of the f008 0:z*nxts l 3a ozq;iotuzsatellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gravity9 oa1qhwjm,ap -hq . 7q1wa6ot is mq .jaw,1a7hq -9ohqwa6 t 1op$32 \; m/s^2$. 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 ha8v7u0-imw)kwknnz6n3 za tu 7 ar;db)s radius r. If the object is raised to a height of 3r above the t6awnuz)kann7u zr)m3w0v ki7;d 8 b-Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes from67 jaff3.u ugd sea level to an altiu j37f 6.dgfautude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radiusk(me ejf0:,o j4jgb)- f *mmdn r. A satellite of mass 100 kg is at a point 3r above the Earth'( m jfegj0*j:k-4bmndo m,)efs surface. What is the satellite's weight?

  A spherically symmetric planet has fxr1iad tk,. mr+x*amx8sf0k0our times the Earth's mass and twice its radius. If a jar of peanut butter wmtr.1+si8dk r* 0akxmxa fx 0,eighs 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 f xk6yjv y .ru(o:p1j3on the same line, with the Ear 16x3j.ov:rfy uyjk(pth 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 iwn:c3bwix.b 1jk5fve0s3c7 v s 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 about the Ea 16 3ivqrv.oktrth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean r 1qoirkt6 v.3vadius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skims thei0l1 cb*lh9vw surface of the Earth). How long does it take to make one revolution9 cllw i0bh*1v 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 Eau(aujb;;n rn ;rth. It is observed to have a period of 89 minj ;;(ab;uurn n. 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 diameter of 9vu-vt7. fpz nxu +wc+$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a pvuo 0y2k6 ttsj g:d*-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 o xh51 .pc nl5btw)zk0hrbital 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 an orbit? 5tlhw1bc5p0n zx.h)k

  The planet Jupiter istuek3s-q8x3yk/9* rihi f m 8*ssc pi, $7.78 \times 10^{11} \; m$ 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 pi.e u8a28fs;ml)sjw*4zqpj i0 l qi* is the average distance from Jupiter to the Sun? (The distance from the Ealw)l.u jfs0 s4 i 8j*e i2izpmpa;8qq*rth to the Sun is $1.5 \times 10^{11} \; m$.)