Is it possible for an object moving with a constant speed to acceleratx ga+v h,11uyve? Explai xg, a1h+vyvu1n.

  Consider a particle moving with constant speed such that its acceleration of cosn ;49imb8 ew7z 9ojhnnstant magnitude is alwaysnn94wob 7e m i8hj;z9s perpendicular to its velocity.

  An object moves in a circular path at a constant speed. C 4xzus8.jp9ycjca+ ) jompare the direction of the object's velocity and acceleration vector)+ .j ausyxc8c z9jj4ps.

  When an object experiences uniform circular motion, the direag x j*;hd0 x/zl m0)4dfjxbf--vhb9ection of the accelexvzgmlh4;hdj0- )bea- f xj /x0d f9b*ration is

  Consider a particle moving with constant speed such that id (l3unn:dj 1rts acceleration of constantr1d(dnjln: 3u magnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving f-74w7vm el y7 lvcsv0r)6sldwith constant speed in a circular -y77 ldc 7evmw6)40r svvflslpath experience?

  What force is needed to n)q9f0ilke+ 8 sbyyy2/q od7bj6 cw:mmake an object move in a circle?

  When an object experiences unifl /dzd);ck nxt:y 4l/eorm circular motion, the direction of the net force)4 / l zexdy:;tnkcdl/ is

  A roller coaster car is on a track that forms a circuzga ;ws y0j9v1lar loop in the vertical plane. If the car is to just maintain contact with track at the top ofyaw0 v; 1jg9zs the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a ):xrpkku)2 i ytrack 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 itup)ky i:xk) r2s speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it is 8:oebiwzox9 ic(8 v 1dazw3b 6going straight up. Just as t3 ex i:dvzbia1b(o8o8w9c6 z whe 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 curve of radius1 pgmqql* cq62 $r$ 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 84l7re4u xpk l0v2y ksa 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 forex8kly47k2pulv s 40 r the second time, compared to the first time?

  A car goes around a curve of radius r at a conbu 7 4jqna4dw/x9g -brv/x/zt)xza. e stant speed v. Then it goes around a curve btazjzx rg4-vq//u.dw)e bxx974n/a of 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. If the roa fp5x);; b(f,s2kyxp cbw.ir4qj qv *ad is frictionless due to ice, the car can still negotiate the curve if the horizontax s apvf5.q( 2;kbbxc4p ) jwqi;fr*y,l 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 angle, bun kgn*8k6dw;xg n7z6 qxsp3 v4t 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 l;p6dskn6xnggn *4 q8z7v3wkxarger radius curve?

  The banking angle in a turn on the Olympic bobsled track isxo)fd3 ,qd ;afv 2ozb4 not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will int3afd4)qf2ovz ob ,dx;entionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object mm lq-0lwdb34j oving around a circular path to have both centripetal and tangential accll-wb m0j3q 4deleration?

  The gravitational force betwtp63 gws* vyj.een two objects is proportional to

  The gravitational force betwsi ifi s)trga-x; 7g92een two objects is inversely proportional to

  Two objects attract each i7 qwsn/-o qr2other gravitationally. If the distance between their centers is cut in half, the gravitational s wi2q/o7 -qnrforce

  Two objects, with massesd3hybdm ,of1ky c5:1r $m_{1}$ 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 mas 2dv4ehjv(g sh-kerx.9*x6/xbq ncn 2 ses $m_{1}$ 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 gravit msj,99 ,/lvnxl)3zpcvc8jf ration.

  Compared to its mass on the Earth, the mass of an object on the Moon i yyg7g:hxt+s1 s

  The acceleration of gravity on the Moon o)jox,puk8s x+e6)q uis one-sixth what it is on Earth. An objopuqs)x+xoej 8 )u k6,ect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, theza6bb+9kz q: r(sqb +eb6zfwi0ic1l 46 0qax f rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pj e8a ,h)-fqxjf.5(mqjfd0b/qxt-kb ull of Earth's gravitmfxx). qft(jk b jd-aj h-qefb,0q85/y?

  Suppose a satellite were orbiting the Earth just above the surface. 3hz py9x 5yf0him/f.k odhh,6 What is its centripetal accehxkf,y56 hp 9 mhy h30f./idzoleration?

  A hypothetical planet has a mass of half th)eus+wq6 ybddh f25 j5at of the Earth and a radius of twice that of the Earth. What is the a 5 jubsd26qwf+ehyd)5cceleration 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-sixth what i s qnn*i*p(jy5 vgo69 ouvt0f/t is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the M(n *v/jt vg5ys9 fpi 6oo*uq0noon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twicevamwi+ry *c 8,b0l4 zq the radius of planet A. If planet A has mass m, what is the va804 *,lwq+ci mzy brmass of planet B?

  Two planets have the same surface grvu)uw eb8ipobc,3 um y4etex*6a0 p65avity, but planet B has twice the mass of planet A. I,aywutbu56ie4m 0oep6p*e vb8 ux 3 )cf planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a cirsg,6u0w q ( yap4yp y1:sph(ex;a lv(uvw32mecular orbit (radius r) about a spherical planet (mass M). Whicavq(e vs xlgmu,wh42e6ap0y1p :uyw(s 3;py(h expression gives this satellite's orbital velocity?

  Satellite A has twice the mass ofv f.+d3ly-n um satellite B, and rotates in the same orbit. Compare the two nm3.y+d v lf-usatellite's speeds.

  A person is standing on a scale in an elevum8p8 ;/ dc qwsas4:ty xjo2)lator accelerating downward. Compare the reading on the scale to the person's truqjat4 l:;/)s8m28cusdoxwpy e weight.

  Who was the first person to realize that the planets move l rty;zz-m*6/m:jycp in elliptical paths aroundtc jlzpzym-/m r6y ;*: the Sun?

  The speed of Halley's Comet m:6arfa2qpray7 wjaj6r55m.; f s ctj/ q7c0h, while traveling in its elliptical orbit around the Suf57p. thj2/ r wy6:7af5qaqmama6rc;0sj jrc n,

  Let the average orbital radius of a planet be R. Let the orbital period ns0;(x b 1yammbe T. What qxn m abys1m;0(uantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit aro)xdtteshb5f/s 5 4yq/ und a star in the galaxy Andromeda, 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 ofhyf e/tts/5)qs bxd54 that new planet be, compared to the Earth's orbital period?

  The average distance from the Ea4+bsnsnci.l r- rc8o3 rth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is th l rnc.+ ssicb3-o8nr4e asteroid's average distance from the Sun?

State Kepler's laws.c qxyre2k9 uu 2l25/ os/iscn*

  List the four fundamental foryr/ /qit 6ko3fgxe o66ces in nature.

  An object moves with a constant speed of 30 mekpd -+kwaw.1bg mk439l4nmc39 lunw 9ws c:b/s on a circular track of radius 150 m. What is the accelerati34s-wnlkk lk:u cb9wdm+p9b4ng.3wwe9 1c ma on of the object?

  The maximum speed around a level curve is 30.0 km/h. What i l27xsf5expv 2w+0 j(/s xceocs the maximum speed around a20o xv c/jf+c75 x2xlsseew p( curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicyc;d 2 liiturfcnwg4k:+-e-qu (le wheel of diameter 70 cm when the biui t;u-df-k( 24:lc+wrqin geke is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m ;jz/f4nvnkww 3b,,qufrom the axis. What is the cent,bzu, /fw 4k vjw;3nnqripetal acceleration?

  How many revolutions per minute must axr nf:bp 66: 2mehx4eo circular, rotating space station of radius 1000 m rotate to pro6:o6mx:en2 pf b he4xrduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m rxu nbuku0 / tm +f*s;1u(sc8eflo1) ssadius turn at 96.5 km/h. se )1b;/ux l*80uus+tn cku f(sfo1smWhat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Th4 y1y34f5ct*t qn utike system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the ma iknf1y43cytt4* t5quximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a ;jwbr;z 0-b5n 6zdati strong string and whirled in a vertical circle ozb60zai jb;dnw-r;5t f 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 atta(. gif;t ow/5lxnapkm(8phb 8ched to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the thgxp bi(tn/( pk.8m8ol5a; wfension 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 acceleration of 4g o,j/z0h ozef4when pulling out of the dive. What is the radius ofo0e,h o/ jzz4f curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical lotaqtref1(wptui/:q 4g-1 o y-syb6.c4dki u : op (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fg wpc( i o- -u4fq/tytiqd as6ykt1b:4:u .r1east is he going?

  The maximum force a pilot can stand is about seven times dvw 0iscq*;h -his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, ca ;*0siwc-hqvd n tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m r0-8 zuy0focf td//d5,s7azq zwhoe9 w adius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 3q z00wa/ zhzotue7 d ,5sf-yfdcow8/9 20 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat 73nlo/fjp py1 (v+( q jxaaxmx5.akrqa.e9k7 curve of radius 50 m with a speed of 20 m/s. The centripetal forcv7e x(q5jkykaxa (7 j+xomrq.n31f.ap l/p a9e provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve offrd,yolhj7c( k * u:.r radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tirrho y, lu c.(r*k:7dfjes and the road for the car to make the turn?

  A car is moving with a constant s hx ez+kb10cf*peed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum k*1 0c h+ebxzfradius of the curve if the car is to stay on the road?

  What minimum banking angle v;bh+. av bwh6+nzag/8m ql3xis required for an Olympic bobsled to negotiate a 100-m radius turn aba xh+3hgq;8zbwmv.6n/ +val t 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banc 4.yhr60pv19c j kunkzi,ed8ked 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 pjkq*9bv1f (u radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankx.hx k95z)ue 0 vhvmb.3;mq kl xa04heed 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 strineh4j rcl*ne1 0g is revolving uniformly in a horizontal circe0c *lne4rjh 1le 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 ;nopbg7j +v0 jaidtf9c a/4v6 pit area, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of ca;6 jtfavnvj/04gp i79 o+dbradius 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 masseqdke2 -d6q-7+j 2 sgmew/rf u $1.67 \times 10^{-27} \; kg$ 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 gravitath ,utu/7s2xtv5 m/ywhional force on a 70-kg person standing on the Earth, due to the M2 xhyut5hu ,mvt /s7/woon? 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 F.,+z tx jl9 k5m(rc(ex s-z98bnp vbh8i If the masses are moved to half of their initial distance, wh8(t9cv+imxbs x5-hzr, lek9p b 8zjn(at is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from thefs6 n7xo-:bn ( cysh+v Earth will the gravitational forces due to the Sun a os-+ xs:fc6bhny7v(nnd 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 isc:h2wx9j(gi)txlh0u ;sq4u4st yq/ o $7.4 \times 10^{22} \; kg$ 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 th9.vb jx+)vtzplbe;7q e Earth equal to the radius of the Earth. Wha.b7xp + )tlvqzb9ev;jt is her acceleration due to gravity?

  The radius of the Ea flh :f81q9b5rsq w/hmm.lzh8rth is R. At what distance above the Earth's surface will the acceleratiosfqlzf98q5lhh1mr 8. hm /wb: n of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a 57cd a1jxawl9cr 3r v7distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of ajx3c9lv5 crd17r a 7wgravity on the surface of Mars, is

  At a distance of 140005dj .ffc)nh0x wf/ )qj*d rfa9 km from some planet's center, the acceleration of gravity i5 a*9j .r/fq0d jfdfwhxfn)c)s $32 \; m/s^2$. 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. )jp m;:(xef4as7xym u The Earth has radius r. If the object is raised to a height of 3r above the Earth's surx )mms; 7xa4 jeu:p(fyface, what is its weight?

  By how many newtons does the weight of a 100-kg persog*3aa q c wvtsd67(f/o s3uxq9n change when he goes from sea levo /9fu6v37x(awt3sgsq* a dcq el 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 3r above the E)b- y)1t qm) (fizdtzharth's surfaq(t-zhy))d)1 b ftzimce. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass andovb 09v +trp- (rrxm5o twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this plane xpv90-otv+bmo r(5rrt?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, ,jhf4hswfd7r(0nlcpi83 6pz with the Earth between the Moon and the Sun. The Moon has a mass of 0 hc8ff4jdhn(izr s 6 7p3wpl,$7.36 \times 10^{22} \; kg$; 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 tra1oj. l;:bdm mop;th 6ansported 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 orbitg ndhv74(pn w.2yo) bluoq*d4 about the Earth (i.e., it just skims the 44()q * bd2v .gdpnunoy hlo7wsurface of the Earth). 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 circular orbit about the kay2ae6r/;lg) xs5 2sl+k sluf1o ;wgEarth (i.e., it just skims the surface of the Earth). How long does it take to make5wa /; llgs1fkl 2+eu r2sys a;ko6)xg 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 Earthwt-f6r 0 5en/rlmpw-yt/f5 ns. It is observed to have a period omy rnwr5sp nlt 5/fe 0/wf-t-6f 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 ano y ro3vv2400.gevdvv3l/k7 sfv bai8 orbital 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 Jupiter orbits the planet with :jp w76*vxsfda 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 orbi;r6 s p7nn4q(ws-ow o2qigfr.ts. Moon A has orbital radius r, and moon B has orbital radiu wsp-6; 2osof7q.wr(n irqg4ns 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isq738hobr-in)s n rw: ip/5gik $7.78 \times 10^{11} \; m$ 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 1srps3v 5 it(hr;n7ptrs+;6 zk/njtx/ 2 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The dist;r x7 ts jr;/5h3 ivp6+/tpzt(nksn srance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)