Is it possible for an object moving with a constant speed tow:*+ p afztkgm1:d0sk accelerate? Explain1kd:ksmf0p:gwta+ * z.

  Consider a particle movi g2ui z*g01e1cdumg; mng with constant speed such that its acceleration of constant medg cu ;*m10i1g2zug magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare t(d,a/g cwl9 cuhe direction of the obj(cag cl/wdu,9 ect's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction91 , qapgor2ra of the acceleraq g,ror1 a2a9ption is

  Consider a particle moving with constant speed such thar p 7s:2bzr1qqt its acceleration of constant magnitude is always perpendicular to its veloci z q:71r2rbsqpty.

  What type of acceleration does an object moving with c /(pt2f h0pgoa 4imd+aonstant speed in a circular path ex4aa p0tpi/+hg(mdf2operience?

  What force is neededft rdsvhk 319.fs0y )i)zsuf+ to make an object move in a circle?

  When an object experiences uniform circular maa8k )0dn9bwu+kdf* +yiu 5zx otion, the direction of the net force iu0* +8 5daf+a) 9yxdwzikkb nus

  A roller coaster car is on a track that forms a circular loop in the6 y,eix gu tfku)/d:g3 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 centripetal acceleration at tg/g d,u kui:t)6yf3exhis point?

  A roller coaster car (mass = M) is on a track that forms a circul -xiq3qc*yo 0yar 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 miny q*x-0oiq 3ycimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it (,,bvtjkyu do:b 8eohdy*7 7u is going straight up. Just as the plane is at its lowest point, the force b7 8 eo*du:yht( v,yjub,dko7 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 radius21c*g(d+ p dqvea4rf gxpmg*yuw7/a3 $r$ 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 goeo5 civaof,i:9q5lb -/jk p 7yys around the same curve at halol 5k5o9/yy,p j-f:biv7qi acf of the original speed. What is the 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 rf;8mrj o, slaf( m/qg1 at a constant speed v. Then it goes around a curve of radius 2r at speedl fg q/(mm, ;jafor8s1 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 speedwni8t2i8 pxc / v. If the road is frictionless due to ice, the ci/8px2 nc twi8ar 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 bankgjw 1t 8c/b zz z87q.lw+qlh,fed at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run)zqtwflb8jw1z .zl 8+7h qgc/, for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not conssz0dzp8r grjz y x8.59: bzc;wtant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "cli zr:zjz0sg58w;.dz pcrb y9x8mb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circulatr 2i( n-wb4ob5 kv1bqr path to have both centripetal and 41vboq-n 5kbw r(it2 btangential acceleration?

  The gravitational force between two objects is pro0j-i q*oya qf-oh+tk(5 b/pd m(;, wey3ccn uxportional to

  The gravitational force between two objects is inversely pr866g;)klu 4rlkv c gsboportional to

  Two objects attract ea:l kjm6)zvnt 5ch other gravitationally. If the distance between their ck :lnj5t )mvz6enters is cut in half, the gravitational force

  Two objects, with masse 1s+/ys)gyiy:p: a ymus $m_{1}$ 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,)h );ca7 5iogsshk+h9 v usyees $m_{1}$ 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 gravitat5.zm oxipke; n;5t(pcion.

  Compared to its mass on the Earth, the mass of an object orw(j yw t /:35pgqktd3v 7-/ ys*ytie0xu1m con the Moon is

  The acceleration of gravity onhp/2g 9/ebcb1(ppnzd the Moon is one-sixth what it is on Earth. An objec(1/dpe c ng2/bzb9ppht of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves aw4- b waox-0gsiay from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At asa 823zwcncujqoy -: ,*vdi u1l7py(what point is it beyond the pull of Earth's grdsiy2 * np,ajqv:7acw uu-l1(oz3c8yavity?

  Suppose a satellite were orbiting the Earth just above thelxk. 0 *sug(ff surface. What is its c*sf. ufxgk0(l entripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radjnz :bi:-uvj7rf /uj2y1x) pvius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, theyj- jv:nvfxub1i u2:7jp z)/r acceleration due to gravity at the Earth?

  The acceleration of gravity on t0rc,+vbj.i i she Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earthb, v0 rsc.ij+i. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius op:y5ly. l1f6 bg).gq f;eupjy f planet A. If . ;1y6yl blu.f jpgeqpy)f 5g:planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, butu6t,6vh5k9c :jop zzx * *uvnb planet B has twice the mass of planet A. If planet A has radius r, what is the radius of plan6:cuzut*ko, x65njp*z 9vbvhet B?

  Consider a small satesrd2j /u ,myk+llite moving in a circular orbit (radius r) about a spherical planet (mar2mjk dyus,+/ ss M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellitatxd5 2 d)rzm7e B, and rotates in the same orbit. Compare the two satellmx7 ddzt5)r2 aite's speeds.

  A person is standing on a scale in an elevator accelerating downwarduxt8oh7..tx:a f koi;z3u kq7. Compare the reading on the scale to thek83t7u.x:kxo za;fhoit u7 q. person's true weight.

  Who was the first person to realize that the d8oxg*ei d0 0bplanets move in elliptical paths around the Su0beodd8* 0gixn?

  The speed of Halley's Comet, whif+)ux1rs; his a+nv o4le traveling in its elliptical orbit around the Sun)1a nf4+v ixr;usoh +s,

  Let the average orbital radius of a planet be R. Letyo*69iriec*ktiq p-p t;( uv/ the orbital period be T. What quantity is constant for all planets orbiting the -9 tp (p;u6cv *r*iqiyike/otSun?

  A planet is discovered to orbit jocg8:8 :qea i r4jx1naround 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 of that new planet be, compared to the Earth's orbita j4ani : r:cg81q8xeojl period?

  The average distance from the Earth to the Sukfzh.(q//1fq1vq- thv) f cinn is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-tqczfvf f1hq/n t.hqi-(v 1)/khird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. ai/orv 1ji uw7vb-l)*

  List the four fundamental forces iw2 xc,6obn 7whf.f9r-to vq+lvo;p v1n nature.

  An object moves with a constant speed of 30 m/tcx9v;ln4a 9 vd59lt8 b6v zbus on a circular track of radius 150 ml 894tbl5vtd v ;xzu9n69cbva. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 3l)w gue ob8)f/hj oxt/:l: hakm/h. What is the maximum speed around a curve with twice the radius? (Assume al/lu ft :ohwgbj3 :e8)/)x holal other factors remain unchanged.)

  What is the centripetal accele vb8 w69twau egy-v--vration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s?vvv-e- ygtw u8b69a-w

  A point on a wheel rotating at +.pjlbrx* f-dym 8cajwltfla04 3g 3+5.00 rev/s is located 0.200 m from the axis. What is the centripetal acceleratio4plxw ta m30lc bfj .+ flg*d8a-r3+yjn?

  How many revolutions per minute must a circular, rotatinghoqj7ycb0a df 51 0r0h space station of radius 1000 m rotate to produce an artificial 007 obqhfdh 15ray jc0gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiusa wzjgf- gt6,) xf:qamx 6s9.v turn at 96.5 km/h. What is the jw)mag xvzax6q 9,:t6g ff. s-centripetal force on the motorcycle?

  A 0.50-kg mass is attachh0 :pr( zal9f7ysexi; e0+ ct 7ck7dljed to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension t+7clas0(t rf ezhcje7; y dx7i9:k 0lphat 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 strp kfs+vmpz; 6;ong string and whirled in a vertical circle of radius r. At the exact top opspkzm v6 ;+;ff 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 attached to a strong string andj8y - syq zlkzs wc(qiea;p(/mhb987e) c(gv* whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the strwe bz8hcg msqs7*( yijc/ 8lv-ezaq;9kyp(() ing is 3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/ jty:v aj:)c1l vcz),ps experiences an acceleration of 4g when pulling out of the dive. What is the radius pv::j,z))lj ta vcc1yof curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical 32 d bodfcm*w,/fr/n7;n0uoy uzw*8-rgcc ftloop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his ,dzocur tr23n/7 c*m/;gofffb 8-nu*ydwwc0loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a ++fm,(giavhipilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet pl,(+amg+hviif ane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s r j ifd9v+1iy6 2))tukr-bdrrv ounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this carv)j+ dd1kv)firi9 -2utry rb6 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 50i14tyv;bv ej:m6b(n.a2uf g p m with a speed of 20 m/s. The centrip6f;g1v 4n mep :at2.(yuj bbivetal force 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 radtct k8 koug09;ius 50 m at a speed of 14 m/s. What must be the minimum coefficien0;gkoc 98tukt t 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 m qs-s(lhf z/wy .h1om(b65g a3vl gv5a level curve. The coefficient of friction between the tires and the rsfh v(olhs 55mmlb(3gav1z .qy/wg6- oad 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 Olympb8j8md 5pou8s ic bobsled to negotiate a 100-m radius turn at 35 m/s without skidd8bp5 jodu m8s8ing? (Ignore friction.)

  A horizontal curve on a be y;rw k 9-npo2l+*lnbobsled 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 100 m, banked at an antu0fwgp(ivc*0y- f-y gle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked au1. mgs57mya-isy vu1 t $45^{\circ}$. 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 ozil 6ejij* *3pw n5:dwmn52ihq:avd ;f a string is revolving uniformly in a horizontal circle of radius 0j5n3;dl2qvih:*w jzimn i5pd6e*wa:.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 arh sf6/c:d 7khnkt.f( enm0 3hrea, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular tra:tr(nm shk6e3d0f hhn.fk 7c/ ck 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 proton of (*(8 d zugutpcmass $1.67 \times 10^{-27} \; kg$ 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 fors2 l..gyy(p rhn2si g:ce on a 70-kg person standing on the Earth, due to the Moon? Thes.isr. p:y2(2yn lggh 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 forceo* 9t-:pky008pgsiles t/ywj between two masses is F. If the masses are moved to half 0ypigo0t*sp -s:l/ 9t y8 jekwof their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the S36 ce/:8aoqi e1jtw yj q.j)qcun, at what distance from the Earth will the gravitational forces due to the Sun anc:qjo ij8)1qa q .cweyjte36/d 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 kgvvyet7n2aae2/n +5u 1 mw: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 for a "space fcl)4wposx73*s . eqakn16ft-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gr cpfksfq)et 3aw1 l4ns76x* .oavity?

  The radius of the Earth is R. At what distcd-3n )ds0ljm ance above the Earth's surface will the nl0dj)c sm -3dacceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars in,z +/1nnuzm at a distance above its surface equal to 3 times the radius of Mars. The acceleration o 1 +,nznniumz/f gravity of the 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 gravityauapcgg+/9vike4e )3,fyzu 2gwj )l * iig p gkeuyg3)v *+,94)weuzac2 lj/fas $32 \; m/s^2$. 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.e- d nk3ccq7iv :ynfq2ontm 9c+ t(vr)e (*v5f The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is iqyo) v-cqn(i f5ft+nn :tv* cd23e rve7cm 9(kts weight?

  By how many newtons does : a5qpa4 b4n;qll n2gi n/fd4zthe weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean raa;45q/:lnnlb4 fdqan 4p 2 izgdius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satee,x3s u*0youim-9a/sf grr 3fllite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weig u- 0oarmr9sfu/ges3x ,iyf*3ht?

  A spherically symmetric planet has four times the Earth's mass and twice itlnf(f*4nkh len. rp/1s radius. If a jar of peanut butter weighs 12 N on the surface of tnl ln knrf1e h(p4.f*/he Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all z*b5 j2t8ruk o+1f nmvlie on the same line, with the Earth between nzo8k*+ 5vju tmb1r2f 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 transportv lzi:ecpb h7vn(6ph++9 b1q.6 hqh s8f-szld ed 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 hk qul8 u;:gszymb9-knzj8 *+the Earth (i.e., it just skims the surface of the Earth). What is uzh- y;k+mq*:8l8j9nkzubgs 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 j; dwt 39tl*ataust skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the E;tt3d9twa *l aarth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit u fi76beug5:a 230 km above the surface of the Earth. It is observef7g ab6i5:euu d to have a period of 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 an orbital diameter of um0boni9f- jjiv 8 3q/$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits theixt+/y)g8t0u i ht6de planet 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 circula()ib3b+f+ rsnpi 15kutav*x 6mmkp v4r orbits. Moon A has orbital radius r, and moon B has orbital radius +3i s()xmvvkr4uk* m6n5ti+ bfpa1pb 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter icgb y0 3pj:,g3sqy 7e fanho p.j5(4zts $7.78 \times 10^{11} \; m$ 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 ok e,n2-utohab91 xy*wnce. What is the average distance from Jupiterh a 2 koywe,*x-n91btu to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)