Is it possible for an object moving with a4h.8bsid we04a-vnb:( stmk t constant speed to accelerate? Explaihi km.4b(swat:8- dt4nbev0sn.

  Consider a particle moving with constant speed such that its acceleblw *2 b,gv/q(cgnsp - fn59hwration of constant magnitude is always perpendicular to itsl(n9 c5b*nvhpg2, / sgf wbw-q velocity.

  An object moves in a circular path at a constant my2t ym6 94sj f) ckq w;w)mlcg0q;i(tspeed. Compare the direction of the object's velocity and acceleratio6qkjw mqig;t c(49 )fc )2ym;tmys0lwn vectors.

  When an object experienqhi r206a+h 8f-cmotj: sq5nxces uniform circular motion, the direction of the acceleration: hqnio-rax6s80 2+t jfqh5m c is

  Consider a particle moa0 gr y;9s7*x..:,xbi2hzubd b cgk ogving with constant speed such that its acceleration of consta. 2x.bi *,ga9 k7zbh0b;oyusggdcrx :nt magnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with;p 8mxu93ff/ kp2koc m constant speed in a circular path exper mpf/3u;o8kc 29pm fxkience?

  What force is needed to make an object move irg 0;o*iqirrdh. + it8n a circle?

  When an object experiences uniform circular motion, the direction of the nev)u tv1:+sq aet forqv :+ )veatsu1ce is

  A roller coaster car is on a track that fof3(8l7iuqn 4r8)7mofcptuxp 7f5 uwr rms a circular loop in the vertical plane. If the car is top75 )(r7 nq lcu8ptfr8uxm ifu7f4w 3o 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 (mass = M) is on a track that forms a circular loop (ran3/-uykit63xx w eko;dius = r) in the vertical plane. If the car is toky -; ex/out w3x36kin 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 then follows a semi-circular arc untiem h0ddm ,jyqd20t m/(l it is going straight up. Just as the plane is atq/ mj0h,te 2(ddmy d0m 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 cw rgn/+-wtg9hurve of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a 9gags)*oor: d7-gsq j curve of radius r at a constant speed v. Then it goes around the same curve at half of the origsgas)rg7qg-d oj o:*9inal 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 r at a constantc5l rhbem ,5l,(rb mg7h(u8df speed v. Then it goes around a curve of 5d,(bl rb5gcu fh8l(m r 7e,mhradius 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 radius9n7wofi2cd g- r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal c 7icg-n f2dw9oomponent of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are ba8u idwoq p 45+p4f2asr7 fvci-nked 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.pif8p 5-a2cifsu7odw q+4v4r What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsl 2i+/dzuu, vqv/bk979toe quv ed 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 ofud,v7quvu/qv9o t/b e2i9k+z the turn. Why do they do this?

  Is it possible for an object movin-l,n ugq 4- kqwimhan9 h.tb*7g around a circular path to have both centripetal ak qn- t-,*gnhm.h7l9wbi uq a4nd tangential acceleration?

  The gravitational force between two objects is proportou 1wcx// .dvuional to

  The gravitational force between two objects is inv ;xfvl32) z dd-n wkq-nmgz*1eersely proportional to

  Two objects attract each other grav+3eg gx.husd:zo2 .qpitationally. If the distance between their centers is cutpgzsx.gh.u+: o3e2qd in half, the gravitational force

  Two objects, with masses h3lwt *u52gceete3p3esnpfy0h/) r +$m_{1}$ 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 masse6xqm)*g r6vp(j uj7nzs $m_{1}$ 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 gravitationw*j0dgy+8 utx .

  Compared to its mass on the Earth, gmn 5tc l4f7hd*qno+6 the mass of an object on the Moon is

  The acceleration of gravity on +e0z9qfr e3 7t wn(dutthe Moon is one-sixth what it is on Earth. An object of mas eq (0d3n9te fw+truz7s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weigh k,;y:1.0n qkx nhxkpht

  A spaceship is traveling to the M s1)rejgctb.u-i1j, doon. At what point is it beyond the pull of Earth's gragb. eti- 1) j,usjdr1cvity?

  Suppose a satellite were orbi ; p,kva /.anmmq-hh+hting the Earth just above the surface. What is its centripetal avap;m+haqnmk./h,- h cceleration?

  A hypothetical planet has a mass ofgfcb6 j-m y0w 1c ,ytn-qczi.; half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on tq;b wc m0y j-tnyf icz-g,.1c6he planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sxwu+mbk xins+c9 fky31f; 81tixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earthyx+t1ifxu ms8ck91b;+n kf w3's?

  Two planets have the same surface gravity, but planet B has twice the radio87e)bup. 9jb4yty8t qcm (zmus of planet A. If planjy9zec ( .q8)btu7my8mpt 4boet A has mass m, what is the mass of planet B?

  Two planets have the same 6*3lj,obrc( gdpzzhk9l* ( lysurface gravity, but planet B has twice the mass of pl*(*kczdp 6r,bgl( hol l 3zy9janet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbitw smq w5.80jmq (radius r) about a spherical planet (mass M). Which expression gives this 5qsmmw0qw 8j.satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotaitfw9.equ k8; p8 k6xltes in the same orbit. Compare the two satellite's spe;qwe p86f lk.utkx8 i9eds.

  A person is standing on a scale in an elevator acceler yn/s)s6 kve7x(pjym *ating downward. Compare the reading on the /skje)y v (*mp7sny6x scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical pa5 lzsuu 2 au75*7xqughths around lu7 xs* uqhazu57u52gthe Sun?

  The speed of Halley's Comf;sowlfr o; .(2ag4i9ozw-br;dc.q 4oyr i4zet, while traveling in its elliptical orbit around the Sud4r.9iiq;yoza gosl;;(w rf f r o4.w4c-b2zon,

  Let the average orbital radius of a planet be R. Let the orbital period biv-/am6w2y hce T. What quantity is constanyhic6 /mwa2-v t for all planets orbiting the Sun?

  A planet is discovered to orbit a l+1x .q(tfzosround 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 txz.ft1l q+ (sohe Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronou qz,qybs 3,5ymical unit" (AU). An asteroid y5,q,3uz yq sborbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ws( wu5zof6g8 bn h5f bb3mi;6b1z .fp

  List the four fundamental forces hf099 /x dmxt1 3c)reno+rog min nature.

  An object moves with a constant speed of 30 m/s on a circ/5avj -ya1ntoe 8f1-mgcgcw +ular track of radius 150 m. Wha1ywoegj51 /m cv aa+gfnc-t-8 t is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Wha2f2l 8bs3qu;nk:jio28bo vlj+hceh+ t is the maximum speed around a curve with twice tj 32;bi+8conh l+fhb8juq:kse v lo22he radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the) zfs17uudym ( perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 mf)uuy 1d z7ms(/s?

  A point on a wheel rotating at(17 7gjta tqymxd/ch6e/ 8-/bq omhws 5.00 rev/s is located 0.200 m from the axis. What is the centripetal accelerationxejyo a w6 7dgt1m-qt7mb hch(q/ /8/s?

  How many revolutions per minute must a circular, rotating space station of2zztt6z (x) rz radius 1000 m rotate to produce an artifici(z rz2z)txz6 tal gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 med0nt+ v /mlz5 radius turn at 96.5 km/h. What is the centripetal /tmd +z5v0en lforce on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The s b.br, l 7etilfo npn7(v14v c27gt(toystem is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What i7fo7v7( 2 telbn 1 rc4gp.b,(ttiln vos the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strocw*+0ecm+ .5 stmhhyt ewp-f 8ng string and 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 spe +mhyw+8*ewc. -ftm ct0 5hspeed at this point is given by

  A stone, of mass m, is attached to a strong string an/g296bfn ug jad whirled in a vertical circle of radius r. At the exact bottom of the path the tgjgu f96b2/an ension 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 experienceff 3(/r ezs7nvs an acceleration of 4g when pulling out of then(7fs/vf 3rze dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical looplorty jh539 c, (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down o 95r,c3jtlyho n 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 we6tq7+sr1 bcc g3j(p1t z.uoc yight. What is the minimum radius of curvature that a jet plane's pt(bz7gco. 63pj s1 yuq1+ctrc ilot, 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 horizontal curve with the tiecq jr/f;yijo(6r 9+h8ss4 wzabo,d/4 yfh2ires on the verge of slipping. How2f6,ii8ydyjq ws zca hs4o b4 ejr/;o9r/+(hf 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 7 mv 8ca5ca8fua flat curve of radius 50 m with a speed of 20 m/s. The centrafacc7 8mu5v 8ipetal 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 radius 50 m at a sp/ b+k 2f7ydutg.ukqs+eed of 14 m/s. What must be the miniuqyk ./d+skt 2fgb7u+mum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a (y/, zv: 38tyq waqcxrconstant speed v around a level curve. 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 s z(yq3/:,twqcvyarx 8tay on the road?

  What minimum banking angle is required for an Olympic bobsled to n3ks6f6 u6zge degotiate a 100-m radius turn a6u zkdgs6e6f3 t 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled jnck2naie 5 8te fwjr5c;66s*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 angk2 /.ejyz(;3 oekgdflle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankyv1v g66qil:qwy g3+wo (vfq5ilba. 8ed 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 thek7iv0nes7s52folir c6 p:+im end of a string is revolving uniformly in a horizontal circle of rim+i ilopvfc7:nsr52s ke7 60adius 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 unif53 dc;e y/3dax/lkpgzorm rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill ia5 /3;cgl3ddy/zk px en 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 massyn. inxu*.z zort7.p5 $1.67 \times 10^{-27} \; kg$ 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 t8 fcqh u s03h:gp,x;von a 70-kg person standing on the Earth, due to the Moon? The mass of the Moot:su0c,hpf vx;3qgh8 n is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attr/i4k fv i 4*buk x omkg-n;((suwck;y3active force between two masses is F. If the masses are moved to half of tkk4vgi4-/m cx w(*n;ob sk;3kuui( fyheir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what dwllrz gl+/ks 885gyo,1kko d5uok1 8d istance from the Earth will the gravitational forces dk lzkkowu,gd5/5 llsgk1+ 81ord8yo8ue 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 7l8kh4 f,scybis $7.4 \times 10^{22} \; kg$ 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 to;qt: v jeockwq+z, 135zrg*ce the radius of the Earth. What z; w ,krt v*eqgzo15+3j:eccqis her acceleration due to gravity?

  The radius of the Earth zy84zzo tqfp2 ))2 vghtr0/vhis R. At what distance above the Earth's surface will the acceleration of yh8 2tvr gqf)/thzz 4 ozv20)pgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance a7 lj r)f)gs9.yjgbl (pbove its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to thlgr 9 y f)7gpbj.js)l(e acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of g0f je. :mw*qffravity is*ef j0fw.qf m: $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432)d 7i3u 8oubds N 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 surface, what isub do3)sdu87i its weight?

  By how many newtons does the weight of a 100-kg person ceyl.p,yb; mh;, ogo; wan (+rjhange when he goes from sea level to an j;y(y,ormlgn +b. ,who; pa;e altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satejx//ve.,p v)zd h9qwz llite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weight? . dz9zjvxeq,)/vw p/h

  A spherically symmetric plwgwl k (h:2b n+a4;z a)-6qrlws/x rd6dg ll;danet has four times the Earth's mass and twice its radius. If a jar of peanut butter weigh ;/dxl l -)66dr zr(+w2swl n:hgl;da4wkbg aqs 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 on zy ;tafv.,s;ed5b7e dthe same line, with the Earth between.;e 5dtd, 7bvasefz; y 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 transported to the Moon.kz4m (7q cfzr,
(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., 5 p 1uh-ja vv l7bs7z67siscsn8,h/eait just skims the surface of the Earth). Whj hl- bvu7s 67 azsaiv1nec7s,s8p /5hat 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 E rf7 ,j,cdikf+dms7ov w-*yvsf6:1n t,kbcs+arth (i.e., it just skims the surface of thetds7 6y+n,*dm,k i:roscf1jfb +f7,-vwv kcs Earth). How long does it take to make 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 Earth. 4v*p.q,a r ysoeq2g.t It is observed to hap,q s.*e o4tgq2 rya.vve 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 Juz- 16 tjq kt7cje;n2w;f- hexmih 1x;rpiter, has an 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 a radius ofgygg-:3nzor9 *bh)vnm.l/+bfanuyxi5li 3 , $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in ne3*: khueg lq9early circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete9e: 3 kghelu*q one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter istsxjpylp-e7 ) p)s)(p $7.78 \times 10^{11} \; m$ 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 q sq-- bj:m,y ab qg+/om)o5jvthe Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Em byojabqs, v+o-/5qqj g-: m)arth to the Sun is $1.5 \times 10^{11} \; m$.)