Is it possible for an object moving with a constant sd9 *rw8gzr pl 3g(0hmhpeed to accelerate? Explai*gm0p8 ( hdr9rlz3gh wn.

  Consider a particle moving with constant speed such that its accesk iktr.c964 wo 0zs4gke0 bn4leration of constant magnitude is always perpendicular to itstnz w sbc4k9i. 0k64 so0gke4r velocity.

  An object moves in a circular path at a constant o+z.3/)1awdga4hg 2t jfh)f yg hk/ uvspeed. Compare the direction of the h adg.f/+avf)gwzutyh g2h/ ) oj1k3 4object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the acvve 7tmg3lh 45celeration is evhtm7gl54v3

  Consider a particle moving with constant speed such that its accelerap kzhb6g,o0y 0tion of constant magnitudkzh pgoy0,b 60e is always perpendicular to its velocity.

  What type of acceleration does an object mo d3+4 s pw* ;.mz8eb/cnbck+hzf:d hlzving with constant speed in a circular path experiencdh8 /4e+hz*nm.zc:plbz 3 ksbfw dc;+e?

  What force is needed to meko-s*w 6vmh 9.badqjt .iwdq6j(-6 jake an object move in a circle?

  When an object experi kmyhisziyv(ix7 -9m961y/v eences uniform circular motion, the direction of the net force i z9vxy7i(mse-/my h6vy i19kis

  A roller coaster car is on a track thzv ,xlxy7 ttm;69c:zv at 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 minimtzc ;6z v:x7l 9ty,xvmum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a . lu p/ru,l/i:zi e9otcircular loop (radius = r) in the vertical plane. If the ci/l,irltuo9z p u .e/:ar 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?

  A pilot executes a vertical dive ther7o/ vg px7bn:9;g/lx cu k6qpn follows a semi-circular arc until it is going straight up. Just as the plp7b ouxp7 ggqr k6/:v9;lxcn/ ane 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 ofe)vjl;i c( +xrqc+n p pues*g4t8 av/7 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 constanybit.n .gs2(gt 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 goebn. y .g2sgt(is 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 goes aroun )qlrykwx*k ikry+b4q nq94, -d a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes aroun rb4 l *q,k-y9ky k)qx+iq4nrwd the second curve, compared to the first?

  A car of mass m goes around a banked curve of rayz g,ww1 v(q s5)aj-whdius r with speed v. If the road is frictionless(g) ,wsjav1ywz5qh- w due to ice, the car 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 bankeqhqw7xcl .t47d at the same angle, but one has twice the radius of the other. The safe speed (no frictiox7qcqw t7.l4hn 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 :+iw(r*lt7g dflfw8d a turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Why do they do w(ldif+g8wtd fr7:*lthis?

  Is it possible for an object mof+ u)4s;rgz:*r4tvkvw 3wz df ving around a circular path to have both centripetal and tangential accelerationvk *svfrt;z: wd)u4+zfgw34r ?

  The gravitational force between two objects is proportio k(ev ;.qbs1bmnal to

  The gravitational force between two objects is inversely proport- xvv 7hfro2l;ional to

  Two objects attract each other gravitationally. If the distance betw- zaugxshe 90 9eekm:,een their cente:ug ,9s-9zmeakhx 0ee rs is cut in half, the gravitational force

  Two objects, with ma4n6zqk/ o1ll jr4z,c osses $m_{1}$ 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 massessqla7mo ns ,ps49-sq)fy+9j c $m_{1}$ 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 unid3/ .v la:gyljversal gravitation.

  Compared to its mass ohso ;jf946i exp5q u)in the Earth, the mass of an object on the Moon is

  The acceleration of gravity onxqs66*(4qh -ocpl xsc the Moon is one-sixth what it is on Earth. An object of o6c(pq4 6xq*cxl -sshmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfacebn;m1n 4cunk*::obb l, the rocket's weight

  A spaceship is traveling to t13qg)gcja bb+ he Moon. At what point is it beyond the pull of Earth')gjb3 q1c+ab gs gravity?

  Suppose a satellite were orbiting the Earth just above the surfajer)p)r ywgg;+pounj b;6w;3b,;xxc ce. What is its centripetaljrwexgb;jx + pp);,b) gru;3w ;6ncoy acceleration?

  A hypothetical planet ; h): kp9i rnxf 1uy4bgwm v-/l9saf9shas a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleratg9 yix1)/snfu;lv4aw-brm9k:p f 9 shion 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 it is on Earth. The 4hqhr ;6a1nok*nzu k24 s8nraradius of the Mnr12n4zkor8 sa uq;* h6ahnk4oon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the x/7o4whb)tay h x:a)dsame surface gravity, but planet B has twice the radius of planet A. Ifhxt/yd )a:7a o4whb)x planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, butj( s94ah;+ zfa.oghyi 8di(tsx. 2w hlaa9md1 planet B has twice the mass of ply;shj4ag+h.ad af ai1(hswl(xdi9 tm z98 2o. anet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sj s:rrho60ka4 pherical planet (mass M). Which expression gives this satellite's orbitaloh ks r6raj0:4 velocity?

  Satellite A has twice the mass of satellite B, /jnl3 h(+bqss and rotates in the same orbit. Compar qn/sb3s+(hjle the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating dowfa9no o: 7p b+x5kxz7 l7k5wqcnward. Compare the reading on the ox5:zcb 7+ wfln 779x q5okapkscale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical pathwi*i /zj ah107* dbbcf: ex(9eqjei /us around the Sun?f aji: wbbxd 1h9*ej / uiecz(ie0/7*q

  The speed of Halley's Comet, whildq9 e9+6mu 5ofyc quxag/:u;he traveling in its elliptical orbit around the Suq9f5 /uqmhuo+yc:ugxa ;de9 6n,

  Let the average orbital radius of a planfd1qptd*0uvbug/:lf .vbt hsj5 dgi3 y.(21oet be R. Let the orbital period be T. What quantity is constant for all planets ob(/j dydq ibfvuv21 sg lof .p*510:h3gtt.du rbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy A6m vp9p / o0jg*:80ciyno wmgtndromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, :p0/0v wcm6ijt*9mopy ng o8g what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as cfp,5lilggz 6( +ln1p one "astronomical unit" (AU). Anl l+fp6p ig n,cl1g5(z asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.wu3 hd e9bv54u h4ewilo xj,b 222is:u

  List the four fundamental forces in naturestirel 95hqks 5kv;yt1r/s ;;.

  An object moves with a constant speed of 30 m/s on a circular trhtgnat( f2hxtaj z+o)28 n- ,er6 if2wack of radius 150 m. What is the acceleration of the objeg6ata (+hfj wo,tzi-2rt2f n)hn 2x8e ct?

  The maximum speed around a level curve is 30.0 km/h. Whalnvmh 5tra6dv z 533:zt is the maximum speed around a curve with twice the radius? (Assume all o 5z5ntvmz:l h6v a3r3dther factors remain unchanged.)

  What is the centripetal acm4r+r 8;tbos* jq+dzo celeration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8 rzos8b+qj*rd+tmo4 ; .0 m/s?

  A point on a wheel rotating at 5.00 rvw+ja9jj p7l me.s- g(ev/s is located 0.200 m from the axis. What is the centripetja l .j-7g (esjvw9p+mal acceleration?

  How many revolutions per minute must a circular, rotating space stae9;nrii bbtxtu7y/ bm q+fu **d-+vq*tion of radius 1000 m rotate to produce an artificial g yd;u* vb bq7+utriexmb/i- q +t*n9*fravity of $9.80 \; m/s^2$?

  A motorcycle has a massrv dqx97i)/4ba ba mlj.,q* xf of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motor74 /a)bqif,* xmrbajvd9 . lxqcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m strr;f ecn svxq432o c 1w7ky:5mting. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. tkrv4 cw;yqf5:no c23 7es1xmWhat 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 vertical )x,lxc2da fy; vaehspn)9.9sh5hl : 4opli:vcircle of radius r. At the exact top of the path the tension in t ;h d)yp s :5is 2hal.cl) x9lo,x4nfhp:avv9ehe string is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and rj e5mn +;f aw5-nrbrdn(rf8k fa- 5k0whirled in a vertical circle of radfm5afe-jr r+55 k0w k-bnr f;(rna8ndius 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 experiences an izi;t p6j3 .o.jxfx8e acceleration of 4g when pulling out of the dive. What is the radius of curvatuiif3j.op 6.tj8z e;xxre of the loop in which the plane is flying?

  A pilot makes an outside m3lhg 2spgc,; vertical loop (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 we2 gm;hp s,gl3cight. How fast is he going?

  The maximum force a pilot can stand is about sevjbps -h1.ei.:a4ikf b 3. hhzven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate fie-hkhiv.hb 4p:ba 1j . 3z.sat a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tiresz3 h jqd-2yb1c on the verge of slipping. hq yc2 zd3b1-j How fast can this car 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 pa.m,chpch,6z1 ps:w curve of radius 50 m with a speed of 20 m/s. The centripetal forc ,6apzh,:c1pp wmhc. se 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 m/,w7rap jy 9xd1s. What must be the minimum coefficient of friction betweejyrw 9xp a1,d7n the tires and the road for the car to make the turn?

  A car is moving with a constant speetpe3:tyc 6ou4e carzs .e(21x 34kmw jd v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum 3 rw26 :3 cp4ae tcyu1xzm.(jtesoe 4kradius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate wy-qm ,8 )heulzh7zv- a 100-m radius tu hzlh8vzmweuq-y 7-),rn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a 4drdqc9 kang3 f2 n+/gbobsled 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 ;d )9*: iokmhejegb/c 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 )mc52r/pj8 yhcy qt1tm 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 icqy) p*8lnf m(n a horizontal circle of radius 0.500ym(nl *cf)p q8
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 uniform f uzdk/8,f4df rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in the blanf,fdu / fdz84kks)
(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 f pr573tys;:kv5g fz( fgbrq+1x;tsz 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 Eai t6kb.yq+i9t o:i s:yrth, due to the Moon? The mass o:9y6tiyi :k+ q ost.bif 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 forjsu17h j .xhioa4q0ah-+2t rz ce between two masses is F. If the masses are moved to half of their initial distancjxjah2z7qta.s-h+ 1h u0 4oi re, what is the gravitational attractive force?

  For a spacecraft going from the Earth towakesdc. 3:d an3,9dq7dyn1d of rd the Sun, at what distance from the Earth will the grscqdd,ok3 3 ny7fd:dae.n1 9 davitational 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 izv) 9ytas9.slk .*(z q)muugji8ej o)s $7.4 \times 10^{22} \; kg$ 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 equal txc)s1n1: *oi 7 wtggqio the rad1 qign:1oi7)xcw tsg*ius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above thw3*u+ik h j c:weg75qke Earth's surface will the accek7iwu j5*:wkgqc e+3hleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfyd-wk*6gh+obw + knj2ace equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to +2wo+jy-h nk* 6gdwkbthe acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration olvjl xlj-5b05f gravity is jj5v5lx- l0lb $32 \; m/s^2$. 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 radieazff* t,sq09us r. If the object is raised to a height of 3r abovfzqs9e 0,* afte the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chang lbmuws5 yv4p :acjp,9y*g9 zf t;*lw9e when he goes from sea level to an altitude of 5000 m? (Tbts ;gl**yj9mf ,v :wcp9w yu5z49al phe 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 abowk41puyzp5 0g ve the Earth's surface. What is the satellite's weightuwg 14pkp05 yz?

  A spherically symmetric planet has(j 7a1x5kvgcm four times the Earth's mass and twice its radius. If a jar of peanut buttevk cm1x 5(gaj7r 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 Mooq g:ueiv0ba t0k:nwq7.:xk q q+i ry/+n, Earth, and Sun all lie on the same line, with the Earth between t7k /.gxqrb : aw0+k vqe::yt0qun +qiihe 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 transported to the Moong3 n py)+sd(:pg z3mak.
(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 ther7q(tjc mw 4 i *wpmos6w ,gdb+t.bzej5a/: h+ Earth (i.e., it just skims the surface of the Earth). Wq dz5( h b.j:w+c pm* mjwwbtg4/oi,rtsae+76hat 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 just r3yfp: po6i)askims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mr3 p)oa:f piy6ean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit,gh. 0p;g8g rjxk. uug 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (ph.8g;,gggjx. k0u ruThe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametera2 ty+b7yy8ywae/r 7 jpi1o; v 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 p:ali)t/ju /ul lanet 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 ;rrnw32 gww m-circular orbits. Moon A has orbital radius r, and moon B h3gwww rr 2mn-;as 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 jnt 9 5zc9qbi6$7.78 \times 10^{11} \; m$ 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 ftx6 d.2fz iz/1:x swethe Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth :wtx6f xi z1s2/e z.fdto the Sun is $1.5 \times 10^{11} \; m$.)