Is it possible for an object moving with a constant speed to accelerate? Exph+ 4( u3iz(b 7gr/h5yca6:jzfbnnf hu lainhhancfrg3zy 5(6 (h4+u : b/j7biuzfn.

  Consider a particle movint izz).50r*fqb sfy;m g with constant speed such that its acceleration of constant magnitude is always perpendic m 0zs*.)yfiqftzb5;r ular to its velocity.

  An object moves in a circular pat ( uq.++q r8i:npzdx xflm3e(kh at a constant speed. Compare the direction of the object's velocity and accf8ixlp mnq(3+( .ud r+:kezqxeleration vectors.

  When an object experiences uniform circular motio )6driaz ufkb.i, k7pm2jy8+sn, the direction of the acceleration i)bpu a,zyk 2+irf k8s i6d.jm7s

  Consider a particle moving with constant speed such that its acceleration of c (tj5gsnj m;w2onstant mag; mj2ts 5g(nwjnitude is always perpendicular to its velocity.

  What type of acceleration does an obj5t ,/pod .yjvwect moving with constant speed in a circular pathv dy /j.5,twpo experience?

  What force is needed to make an object move in a circle?hphz-ytop+e0 yyx *2+

  When an object experiences uniform circular motion, the direction oa 17:. o+om kh/qufd8p zxuf(hf the net forceh(xkud 1p:zu.q8f o/m+7 aofh is

  A roller coaster car is on a trxxlaka 0*u ojfp z0-.;nmo w),ack that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, whatpooumk *;n x0)f 0l,xaj-a .zw is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on+t97lpzhl hi3 a track that forms a circular loop (radius = r) in the vertical plane. If the car is to j+thl 3ihzp7l 9ust maintain 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 vertical dive thery mv41a)ju*xt+ v ob.n follows a semi-circular arc until it is going v1r ay*jbmo +tv4u).xstraight up. Just as the 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 radk5i wzfple k3zw)48 ,rius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius rc3 u3,ax5j*hw/ao i 7a( rlyrx 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 secondu/axayiw(o33hr5x7 *la c ,rj time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goe 42dpwz+df,vpqypm )8u4uwe8s around a curve of radius 2r at speed 2v. What is the centripetal force 84zwfp )pdv+4my 8q d wuu2,epon the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a xj3m)dh2r7 ,oupzy))qzg9 lu 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 horizontal component of the normal force on th,j2)phr)zm ) yuog93z 7xl dque car from the road is equal in magnitude to

  Two horizontal curves ocnfol+ 4 9mr,on a bobsled run are banked 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 radius curve is v. What is the safe speed oo+ ,r49lfmnc on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constanm5qs ;phsfi:9 t, but increases upward from the horizos5 ; pm:hifqs9ntal. 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 object moving around a circular path 4;qz nu0 ,oxo fvcm55uto have both centripetal and tangential acceleratioxvnozo5,fu 05m4uq ;cn?

  The gravitational force between two objects is prop9r,*(g eksez.* 2bxp(pp 5je1 tct rrrortional to

  The gravitational force between two objects is9/4cv/r dhg7wyr7y:4 (ifq kv xzq3om inversely proportional to

  Two objects attract each other gravitationally. If the distance between,m; xynu tu0woqr8wj4 wz4*f( their centers is cut in(4o w,t0n8mxru qy*wu4jfw z; half, the gravitational force

  Two objects, with masses )p *zpa -k8 vlvi8+qgel64jmf$m_{1}$ 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 mass ia-kmqf3l+5ces $m_{1}$ 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 a, 7i6bcq z-9xyo+w:)cslnthgravitation.

  Compared to its mass on the Earth, the m y 9riljrr;x zsfn.9whw/+**l ass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Eart3edh/ ulo*0bl h. An object of ma0u*/blode3 lh ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves awa/0x 3bbx y pnkete+,1by from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point isdmj,*:+mf5n + be xklp it beyond the pull of Earnd, lk +bmf j5*:mpex+th's gravity?

  Suppose a satellite were orbiting the Earth just above x*i9by;n4ajqt.tl : d the surface. What is its centripetal acceleration?bxjtd.ln4 ;a :i 9qyt*

  A hypothetical planet has a mass of half that of thenw 7a6p56e w1xpzuukn5f/ fp)9 gum :a Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to grpgwkme 671n5 )pa:f/9afu5nu6 zx wpu avity at the Earth?

  The acceleration of gravity on the Moon is one-siuxl,zqte8 er* ((lz7j xth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compa (qe e,jxll8*t(u7 rzzred to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of;l2:vw sflq2f4b :kys planet A. If planet A hl4:fl q2 bs;ywf :2vksas mass m, what is the mass of planet B?

  Two planets have the samn lay(gk-5)fte surface gravity, but planet B has twice the mass of planet A. If planet A -5n)( tkaf lgyhas radius r, what is the radius of planet B?

  Consider a small satellite moving in +j1x.-- 2jji koiyoy aa circular orbit (radius r) about a spherical planet (mass M). Which expression g-iio y-aojjjkx+y21. ives this satellite's orbital velocity?

  Satellite A has twice the maux+ex /zgd jz)km14. ess of satellite B, and rotates in the same orbit. Compare the two satellite's zdj1exxueg/.)zm k+4 speeds.

  A person is standing on a scale in an elevator accelerating downward. k.(;p1qsmfs( ahfay*zp+ r 7m Compare the reading on the scale to the person's trqs y1pf k .r;(fsapmza 7+mh*(ue weight.

  Who was the first person to realize that the planets move in elliptical paths a ;3jv;q*oryn,stt+v lr,rl j ;tnt ;o+yqsvv*3ound the Sun?

  The speed of Halley's Comet, while 2gispey((l (+5z8 w jk4)dmw il.l7vzm 3jexa traveling in its elliptical orbit around the (zpzig (weml)( 5d3x k8 7vlljm 2ywj+.4is aeSun,

  Let the average orbital radius of a planet b3 a/eusw6.m *.y5*zroslud no o:v*iue R. Let the orbital period be T. What quantity is constant for da.z /6*u5y seo.m wo* u3lvn*su o:irall planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, qye7wr311jdrx. ,-q -nbj uitwith the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what wil r w7tb1q -3uqr.ijxej,n1y- dl the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the w.:jxitv 7)j sSun 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 the Sunt .:s)xwjiv7j?

State Kepler's laws. 2/8,ybqzy;7vculn;5ia sr;j*gxuke

  List the four fundamentalf 1vif l hs);l+n kg8cy6z:(nl forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radius z+d,pd pai63 y150 m. Wha dpp+i,3y6 adzt is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is thmy07.z)pho sqlc ,ed.h, dj/xe maximum speed around a curve with twice the radius? (Assume all other fdpcj) dzs0/q.y.,lm,h7 ex hoactors remain unchanged.)

  What is the centripetal acceleratiih7tw,4 nclh7 on of a point on the perimeter of a bicycle wheel o,i wl7n 74thhcf diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 r3 7uyat1 bjkp) xgikst s25p(1lf jl+7ev/s is located 0.200 m from the axis. What s21lak uj( 7bpytjl 7f5kg+1ix)pts3 is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space stationimoc gxddo fn 59h/:.4 of radius 1000 m rotate to pr/ cf.n9 dgomhx4od :i5oduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius tkc.2 j0k 8;,xhsrkuvvcs5 f5d urn at 96.5 km/h. What is the centripevdxu,2svch ;rkk 0 .j85cksf 5tal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m cte 4t38exe2i2pb3ev string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed xetteb8v 2pe32 eci43of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical rc86 o svm*g2r3exy 7acircle of rs o yrgae3*cvr6 28x7madius 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 attachehk,-o4t /6 ja nmvddv)d to a strong string and whirled in a vertical cir)tk v omha-vdjn64,/dcle 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 at this point is given by

  A jet plane flying 600 m/s experiea53 r +/ph3sbjibf ;(k7bxjnwnces an acceleration of 4g when pulling out of the dive. What is the radsb/kxwhpnb(f;j j7b3 3rai5 + ius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is bencc+p h ;4,vpo-kccjf:eath him) of radius 3200 m. At the top of his loop he is pushing down on his;4jph+ pcc -,:kfovcc 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 thtm2j6: 2;stq uaz1nnke minimum radius of curvature that a jet plane's pilot, pulling out of2zs1t;:6mjq u tnakn2 a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m rap;*/yfrxs. b :8g fyjydius horizontal curve with the tires on the verge of slipping. How fast can this c.s yf x8yj*:r/p;bgfy ar round a second 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 with a b)0eb4-wqgu9knxp a6speed of 20 m/s. The centripetal force 0a)w6keq9xbbg4 nu -p 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 bydo5bfsy pj40,w/b7 o mtn),keo9,s 50 m at a speed of 14 m/s. What must be the minimum cb fbd,e5ws ,yso07mnbj,9o)o pytk4/oefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. d m3jhp8r:*tv 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 vmpd*tj :rh83road?

  What minimum banking angle is required5,bdyu, nz;g p for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friction.;gzub,d 5,ynp)

  A horizontal curve on a bobsled run is banked at a a y:hzn5v (chk,8 5qwm$45^{\circ}$ 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 radkspk9p n8eg8; q/zh 3dius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m -67 jh9tswx, )tfzrrb 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 end of a string is revolving uniformly in a horizontal circya8g (+g)n zcxle of rad(axg8 zy+gc n)ius 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 y ny+w u5v+zgkc41,8m kgj+xnpit 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 radius 500 m. (only fill ic zjk,gvum5k4yx8g + n++1y wnn 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 .nwye mrc5(5h)lhxk ;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 gravitationae* d 6sstsq* k-qco4p3jyzyma7;.,a bl force on a 70-kg person standing on the Earth, due to the Moon? The mass ofmospqb-a4 ; s6jyy zq e*tk3c7.*a,sd the Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attracto5k3uk(ih a s7ive force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational att5kusik a o37h(ractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from thefp82p4 gs6vh jo5 x) ujtc:ng+ Earth will the gravitational forces due to thesvp cjphn+g xj2)t5 g46uo:8f 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 isuomjqc4p78/8arki *x $7.4 \times 10^{22} \; kg$ 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 forqfv9ap)i f ri30m 63ao a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravity?9 6fi3q vio f3mr)p0aa

  The radius of the Eartwqi+lw/ dhsb- ro 6.4sh is R. At what distance above the Earth's surface will the ac-sl/.wo h iqr6 bd+4swceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Me2 0.e m6rt+mch35ap(p;t /rhstowwl ars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of thepcs0/ +62w rr p h.omtte5;lt 3hmwea( satellite, 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 gravity fybp w1/gmg,3u0f+ bw ism, 1f+fb/gbw0u3w gp y $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 yo-nd8 .-fij 2he e(juN on the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surfacej( ned ifo-hy82uj.-e , what is its weight?

  By how many newtons does the weight of a 100-kg person cha q-0lw9ed *aadnge when he goes from sea level to an altitude of 5000 m? (The mean radius of the Eade0 qdw al*a9-rth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3-dh own *ar*z,r above the Earth's surfacnh*o*z,a - wrde. What is the satellite's weight?

  A spherically symmetf3 yiy 2ku:*eeric planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how muki 3*f2: yeeyuch would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all ldyvo)yc 0/s*die on the same line, with the Earth between the Moon and the Sun. The Moon has a mass of y0/vd)co y *sd$7.36 \times 10^{22} \; kg$; 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 transported to the M+ gza+t; 2rc:jkeq0h uoon.
(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 Earth (i.e., ity ur-. 6i3cjdk just skims the surfaccuk6j.y3dri - e 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 Earth (i.e., it juibuvzil /g:: x0ko; g.st skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth is; ixo lgk/z.b:v0uig: $6.38 \times 10^{6} \; m$.)

  A satellite is in ciryn6xs c)-nnevb5 42eecular orbit 230 km above the surface of the Earth. It is observed to have a period of v4e)es x5-eyn6 b n2nc89 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 an z d2nkmg+*j2f 4sll42wjqq* r 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 pla 8dtm zu+pee 57k40nwznet 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 circular orbits. Moon A has orbital razx+ 80/xclza7gxwu* gix54bi n qpl92dius 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 orbiq izg05 p xb7xlx+ u9wza4x8ln/ci*2 gt?

  The planet Jupiter is6 unm.7d.o y+ho0+ ry tgmpgp.a1om7o $7.78 \times 10^{11} \; m$ 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 thei*-m 8h5)qczdoke4x xq:p)f v Sun once. What is the average veomq4 *i ckqdhp xxf-5:)z8)distance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)