Is it possible for an object moving wixalu9k a.r 4a 6lf;- zosr4t6yth a constant speed to accelerate? Explai; ax tyfo6ra.4ll-ksua 9rz4 6n.

  Consider a particle moving with constant speed sucnr oy(u8,rs1 bh that its acceleration of constant magnitude is always perpendi srr 1,o8nb(yucular to its velocity.

  An object moves in a circular path at a constant speed. Compart9wmkpjpf2a/k/*am ( m qc 1u:e the direction of the objec/kamt/p9pc 1k*f:muaq2 mj (wt's velocity and acceleration vectors.

  When an object experiences uniform circular motion, +.ohq 28tld 4v 0jsv) hfddk0b the direction of the acceleration d) vq0hbk 804 2jl+t. fvosdhdis

  Consider a particle moving wi8re(c l bvcg*b 0q,vy9th constant speed such that its acceleration of constant magnitude is alwa9 c*c vgq8v, l0bbey(rys perpendicular to its velocity.

  What type of acceleration does an object d9vw0og -qu2t9+wxh z82 x vedmoving with constant speed in a circular +9 woz 2vdg -ex2x9q0u8w vtdhpath experience?

  What force is needed to make an obje;h s8*gqc0dl ect move in a circle?

  When an object experiences5 :gbxxp::fhjk ,b6dl uniform circular motion, the direction of the net force ibxj:k f:g:hb,x 65pdls

  A roller coaster car is on a tra bn13a jrsi* , .x7o9,xnz+p ovbxht/51lv msrck 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, what is the minimum value for its3+5n sx 9th,rxo p1asvnb*zb. v/,rixlm1o7j centripetal acceleration at this point?

  A roller coaster car (mass = M) i8lra/0, 20 t1iexu i73qd oarpzd-ogos on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contaixr,a0 eoo goqzi10d 2t rula8-p3/d7ct 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 thenl2x1fr yp nk:9fp8d (y2u*aj q follows a semi-circular arc until it is going straight up. Just as the plane is at itjy fn2 8l*rd( x2ya1f:upp 9kqs 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 radiu :ligjop wk5k( 8)adt0s $r$ 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 n+ngoin 1t x4h.: p5l5;gzanbit goes around the sanga +l:g;1n54i5b t.hzpn oxnme curve at half 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 cur.-a7roj : ohksve of radius r at a constant speed v. Then it goes around a curve of radius 2r at sp7hk-.oj ar: oseed 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 o()a;xft: 1l kw hkc rmsa-ie//f 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 the car from the roat lc-x /;kk/ isaa(efmr1 :wh)d is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the sameavx 6hai5ny 7/di *pa:ppg u9( angle, but one has twice the radius of the other. The safe speed (no frvhu5pa y:nad7 6p(p*9/aig xi iction 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 a turn on the Olympic bobsls gc5haigfjd:re +) l gv2(v00ed 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 lvsgc0:(5hvef j2+ a)0dgigr this?

  Is it possible for an object moving around a jep n :dakw,3x v39mh0circular path to have both centripetal d: jh3ea ,pkw n93xvm0and tangential acceleration?

  The gravitational force between two objects is proportional tkchad4 zout 1)r7t0q3o

  The gravitational forc2;dmk ( rd*u+nt+llejt5* qy pe between two objects is inversely proportional to

  Two objects attract each1d 4ufkkg*vf 6di;y t dm1u6:g other gravitationally. If the distance between their c1uk;dug:y46g1 ffikmtv 6dd * enters is cut in half, the gravitational force

  Two objects, with mass ou/ mt6xz dq;n ;esqb;,s6es/b4cc3tes $m_{1}$ 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 masses vq 9* +on ax:kf/ywu*j$m_{1}$ 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 gravitadf 63ls-u)c pdtion.

  Compared to its mass on the Ear9r y6*/ih:nscqa ge* eir)/icth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth wj y*rf00gh k on:mvzg,8x16zi hat it is on Earth. An object of massgjf z8mirvg*k 0x ,160y:hzno
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Ear3b+5bpe3tp wh th's surface, the rocket's weight

  A spaceship is traveling to the Moor- kl4x cm/c:pw7g*zr u2e qa4n. At what point is it beyond the pull of Earth/2 4prceraz* u gc4-kw:lqm7x's gravity?

  Suppose a satellite wern m z6;l9m.ipae orbiting the Earth just above the surface. What is its cennmla6p zm 9.;itripetal acceleration?

  A hypothetical planet has a mass of half that of z krtoywb 5 ,)jid3cz*/ 3r+withe Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on3)zcy wjr,5ozid*bk3i + w/tr the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravp9n.a5du xrr1(4h vlp+th/cgpg 3 x3rity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moor1x p.cr/x a+(l 343r9g5dgpntvphhun's mass compared to the Earth's?

  Two planets have the same surfacep4 b*5rw :uopk gravity, but planet B has twice the radius of planet A. If planet A haswbour :pp*4k5 mass m, what is the mass of planet B?

  Two planets have the same 5 4 n*dioxw q+ d( t5 27u/,fgonge7nkdfww,afsurface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is w/d(g5noewi+dnf7 5f7o,uagknf 4 xqt 2 ,*wdthe radius of planet B?

  Consider a small satellite movin) rwy*+bc +oz7 tkben*g in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this sate*ewzbyb+ ntr7) *+ockllite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. oz*1mm7g inhg (a31n 4syqdl* Compargs*n 1mdlihoa1 zm3gy4n*q(7e the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating dowz6* / w9zwe2g/mrkhns--goumnward. Compare the reading /ws9mmue/- gn*zo -khz 6gr2won the scale to the person's true weight.

  Who was the first person t(gsg1cd936 r qr 6lo;ou6yaa qo realize that the planets move in elliptical paths aroun soro ql6udy6;qagg6c (9r13ad the Sun?

  The speed of Halley's Comet, while travelingn8: r d2h4jw;gwmbay 1 in its elliptical orbit around the Sun,d24 ;1rghy8 wabj :nwm

  Let the average orbitaafj)z76(ahkm(f7 m ocl radius of a planet be R. Let the orbital period be T. What quantity is constant for all o)m hjm6 z7(ca (fkaf7planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy A4o3xhgg0x0 8rpli)e8fb uzclg etf6 j50q)u;ndromeda, with the fci6 0bq08;zu3f45)8o x0)g gexlrpjh lgtuesame 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 orbital period?

  The average distance from the Earth to t q k2fvl),;ldugqo; )yhe Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distan dog;uf2)qq,l ;ky )lvce from the Sun?

State Kepler's laws. gt)lhg m t,9xqj3s/y n601rcjsu/-dk

  List the four fundamental fowjdt owp p )leb59b.e; s;f/*irces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of roe- 4,a+ wuicqadius 150 m. What is the acceleration of ei4q, ouw+ac -the object?

  The maximum speed around afg4g 3jm a/,n x8aw9in level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchangn43jan/m,axw9ig f8 ged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle w71oy3sm bb7riheel of diameter 70 cm when the bike is moving 8.0 mysb1bi or3 77m/s?

  A point on a wheel rotating at 5.00 rev/s is locat h)mdi1 ij-;oted 0.200 m from the axis. What is the centripetal accelerationd1otmj;i)h i -?

  How many revolutions per minute must a circular, rotating s zqq, ;:zb l-eis6urt8pace station of radius 1000 m rotate to prolzibu z8qt: ,s;eq6r- duce 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 turn m-ks4 s ws k*j w+futz8b2*lh:at 96.5 km/h. What is the centripetal force on the *hzkf-4js l + sbs:w8m2t wu*kmotorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Th+i. idadav lnz.dm( *:e system is whirled in a horizontal circular path. If the maximum tension that the string cad*zi (iadva+l dmn.: .n 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 strong str4/ o.30brcnk 9kyemw bing and whirled in a vertical circle of radius r.nbw.crk0ym b/ 3eo9k4 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 attached to a su ka1k7e pfmz n 7hw:d;s1g2llrv5o.)trong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 wmgp.5elkrzl suk 1v7d);f7: o2n a1htimes 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 when pulling o 1p1ym(: poh7ckk-nx nut of the dive. What is the radius of curvature of the loop ioyx pn (m7h1nc p:-k1kn which the plane is flying?

  A pilot makes an outside verticalwemu 3o1(c zgwo7w1bxk- 6+ip loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pwx 1 mwg o uw7e-c3okzp+1b6i(ushing down on 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 tj6.ouzkh9z,jc33f bf7yw 8 ag imes his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out o w j c7,.oabz3j8gyf9uk hfz36f a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius r+b/ng- /vcg; :ek,mo3 czifthorizontal curve with the tires on the verge of slipping. How fast can this ggv c+3/- zr:k /ni ct;obm,fecar 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 -e2pb((jxee s flat curve of radius 50 m with a speed of 20 m/s. The centripetal fx( 2-e(jese pborce 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 o5tksv d)bp4 8pf 14 m/s. What must be the mini) dvtspk48b5pmum coefficient 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. The coeff612 eh 8flsnivy7ve 6picient of friction between the tires and the roae6s71eynv8v2 p fi lh6d 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 Olympic bobsled to negotiate p(kqt-, j1sr6; uo6p,kp xoyd0cj a:q a 100-m radyrp 0jup -tx6oqkq ;,6: dja1k(,scpoius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bo y(r9: *bczjeh hj9tr5bsled 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 maqft2x:m7 1nsfc.v 7/ gu;er(g q:oe at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked acs()z;r3i)h 7dadx(ir gz 8v b 5en0vet $45^{\circ}$. 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*dx0wzas04z e *zw +rf a string is revolving uniformly in a horizontal circlz*szzef * 04r0dwxwa+ e 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 pit area, a race car accelerates at a uniform rate teb28u yuhob,p*y-) , qd9s 1llf6if vgbu9bh: o a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m.u f -g:9ll,bbv,ud8hyy9*i u)bop21h sqb f6e (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 con:wnuf6sk 1p6a9 hl2xe3 (njcpsists of 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 Earth, duew7d1 ;/lpzg3 q g/,y7pe lvrqc to the Moon? The mw/ g,el1 qpdz p 7ql7v/gr3cy;ass 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 att 0 7a 23yx*ayi:inzzloractive force between two masses is F. If the masses are moved to half of their initial distance, whazoixan z7*3y0 yl:a2it is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what dis3swil e,4woexz ah7tw2 a0j6/tance from the Earth will the gravitational forces due to the Sun 2es a xo,367i /jwzw4t0ehalw 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 is vxeg5pi2)b;) 9q)ot 1sywzpz$7.4 \times 10^{22} \; kg$ 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 toacpb;0:pkmc8 the radius of the Earth. What is her acceleration due to gca;:km80pc pbravity?

  The radius of the Earth is R. At what distance lb5mho;74ncev 01kwpabove the Earth's surface will the accelerat5wm;4vkob 0c 17lehpnion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars atl0epya ,p56 hk a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on th0 ka y,hp6pel5e surface of Mars, is

  At a distance of 14000 km from some pl ,/grk ohf / nxf3nb3t1 n1wk7jwynj10anet's center, the acceleration of gravity is nwkb 7nf,1/k3j n/ xw0y o f1rhn1gt3j$32 \; m/s^2$. 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 theztbl;h 60sl h: Earth. The Earth has radius r. If the object is raised to a heights0t: lh zh;6lb of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes-brs7soff1l7hh7 8;; e)u1pvjirtnj from sea level to an altitude of 5000 m? (The mean radiuisjhjvo7ff7snur; 11l p-bt h)78 e ;rs 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 thek4w g+8j bjiz1 Earth'w 1kgzj +jb4i8s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the E(/ tpzsqa bxi9o7y5 w:p zst83arth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh o 9zbaqp /x8t5:(p3 ts w7ozyisn the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same lin n.be ,2bhuguz p*r58xw y7fh1e, with the Earth between the Moon and the Sun. The Moon has a mass o572yue 1bhu ,zh f8x.b wr*pngf $7.36 \times 10^{22} \; kg$; 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 transpoecw0owuu-q;f rs-e8* (niexn 33z 1 c4qkuj,vrted 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 ornhja095k u w+dbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (T5na uj0 9kw+dhhe 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., i qk6e: *pvmyh;t just skims the surface of the Earth). How long does it tvyeqm *:;hkp6 ake 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 Eartbzf-z 90 +, rpfyy izj.pa.-aah. It is observed to have a period of 89 min. What is the massa. j-yz 0izp-f.zr+pa a,b9yf of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orjwdm1 :n3z9lj bital 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 amw nde8w+2wyvi6)7h x 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 circul*,un,mi,dfd1 3p-2trs-rgr r g xkyk0ar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes rgmt-, 1kypx,kurir ,r *fnd- d2sg0320 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i498zlqkq 7hz ls $7.78 \times 10^{11} \; m$ 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 o:).1 u)eomi a mh(m72pazz lwxrbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance fmiz7m)z.oe pxh 1:(awal2u) mrom the Earth to the Sun is $1.5 \times 10^{11} \; m$.)