Is it possible for an object mo+i) jl/e4ctgculiq 5u7dr7r /:b8ush ving with a constant speed to accelerate? Explaiucril u77thj c4 id)/ /lse5+gq8ub r:n.

  Consider a particle moving with constant speed such that its 87ymbkrs nub u-wnib7p-o(7/acceleration of constant magnitude is always perpendicular to itsn inyp s7bbro7b 7m-(8k- /uwu velocity.

  An object moves in a circular path at a constanti / dcgzh8tx 7f;u1;rm speed. Compare the direction of the object's velocuti/rx8gcm7f1 ;d; zh ity and acceleration vectors.

  When an object experiences uniform:o*m. nk*xb nm circular motion, the direction of the acceleratob .*nk:*mxmn ion is

  Consider a particle moving with constant speed such that its acceleratio2 cks ousv531grwf,n 73et(zvgz 4f) vn of constant magnitude 1rss c 5)(n7ggezf v vwvt2u3of,34 zkis always perpendicular to its velocity.

  What type of acceleration does an object moving with consta)e s )ankvbq-3q o5*ugnt speed in a circular path exper3 -)gsenqq*kovba) 5 uience?

  What force is needed to make an x q/ o0ted0 nofn9ko88object move in a circle?

  When an object experiences uninnchgzpjof: l,pnx nj ej7)r-t/m a; 40 ;)1pgform circular motion, the direction of the net fortj7 /c;n j-, nnzor ;g p0 a1me:phngp4lj)x)fce is

  A roller coaster car is on a track that forms a circular loop in asq/8s 2+ooxkujb+bw6y zowo3 c9: i- the vertical plane. If the car is to just maintain contact with track at the top of the loop, wwc/9+i 2:wszao-kxb36 o8 sqj b+yoou hat is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that formbl:06pb s 8uzp-w/lgys a circular loop (radius = r) in the vertical plane. Ilup l -bwspzy:608/ gbf the car 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 then follows a + v2bhu9lenatla 5c: :semi-circular arc until it is goat la bu9::v2n+e5lching straight 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 cuqzr-;dk4;f a j 7bzen2rve of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve o0gwpe05jsc ,zrwnh,3 p*d(ni 4*srrof radius r 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 c w*pc 0 zo3n,ejh( 4pns*w5irsgd0,r rar 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 constant speed v. Thens v26cj.3 mjcd it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second cm .cj3 2jcvd6surve, compared to the first?

  A car of mass m goes arounn 67qappne,2 s z)vhsbnh k7hq+ (,7wnd a 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 normal7nh2vb+q ),,6 psqz wneps (7ahknnh7 force on the car from the road is equal in magnitude to

  Two horizontal curves 6jwcr1ht b bsq)s* 0+lon 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 smal)ls* 1w q+bbchtrjs60ler 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 cvdoy,ya5 2t7xonstant, but increases upward from the horizontal. Coming around a turn, the bobsled team75 ,xyytd2o av will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object x52ek9s f-k s n,3hnutmoving around a circular path to have both centripetal ts uns3ekfhx-n2,95 kand tangential acceleration?

  The gravitational force between two objects is proportional t s n;y4 ,f;;q4nauxpyuo

  The gravitational force between two objects is inversely pro/bi(f sk4vnu *7jgg1 mtj*hc,portional to

  Two objects attract each other gravitationally. If cjvwr75*tbp2z: dnn -zz80q2pmgy0 mthe distance between their centers is cut in half, the gravitational forcb c*z8 mnyzq p0j-zgn2 70mvpwdr:t 25e

  Two objects, with massk1 x 9k hx.7ri94zllvpes $m_{1}$ 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 massg z/g,i r(/0 sj2lys7st ohf9tes $m_{1}$ 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 qrk8b: ko8 zq r5v719ze+nyop universal gravitation.

  Compared to its massrjfw;k 5wdfq:+pa ;wqi ;,/by on the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-ji8af q6mn1d kx:3 kb0sixth what it is on Earth. An object ofak:83xj1bd6knfmiq 0 mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the)6he8-q vqbfl l0l e y7jzk.g2 Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond q4(7-bb4ge lpa x/a jcb3e( nnthe pull of Earth's gravg7-bp4bxebla (ejnn/ 3 c aq4(ity?

  Suppose a satellite were orbiting the Eart-b8)kabtbcml7 2d2pu) (lr ghh just above the surface. What is its centripetal acceleratiou)) c(r2h p2gb-8balkbdt7m ln?

  A hypothetical planet has a mass of half that of theuzau2 ed :x(w) Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in(ax)z:2wuu e d terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Mo;*quqeoc( 2rsmx 90 :oj6slk won is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared mleq2rs 9;xusw (k6 c:q* ooj0to the Earth's?

  Two planets have the same surface gravity, but/45nkz7 ec(zjdb hqq66uaft ( planet B has twice the radius of planet (dzehn( azbtq56 6j4fu c7kq/A. If planet A has mass m, what is the mass of planet B?

  Two planets have the samy-d2c(,dfk h4g4rs6 ut,plr pe surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet Bcd(yhk,udpsfr4lpg tr -4 62 ,?

  Consider a small satellite moving in iw y09.qnqxp+yvm+.ea circular orbit (radius r) about a spherical planet (mass M). Which expression gives thp.qw x0n9m.qvy + +yeiis satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, an0gta wbhgmhb7 ooi,* ois7,u+u .5zd-d rotates in the same orbit. Compare the two satellite's speeds.*u7 zhw-057o igosb.hto mg ,u,+i dab

  A person is standing on a scal0 3nic2ty7q zze in an elevator accelerating downward. Compare the reading on the scale to the per tznz32 7ycqi0son's true weight.

  Who was the first person to realize that the planetsfa xypfk8 +u 7+pdzg-uog9g(: move in elliptical paths arouzu9p+pf7gy gu d-ox a(8f+:gknd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit a4mqsdgs ..4*y ed.r,/*myrqpqc36g jtd*gjw round the Sun,q q*mj d eqsrgt 4p4myg**d6djw3/.ycs.g,r.

  Let the average orbital radius of a planet be R. Let the orbital period bec*avm+;f j,a w 0prta0 T. What quantity is constant fo*a0a wrvm cp,+a0jf; tr all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromdqb q)j5-u9z0se1 w8g*mkx r s )s4xhreda, 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 dhger18-)*)szk0 uj sxb rqxs4 q5m9wthat new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomica vpl 982e cpqux(p6kb+l unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's av kq+p9bexp puv62 8(clerage distance from the Sun?

State Kepler's laws. tle 8o.q 1ksko)e. 0a8ueqc8 cjy:w2j

  List the four fundamental force;gqr +dqj5dr(8dc:j 4msn h m*s in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radih p, )qr aelju1w/b5n8)yqok(us 150 m. What is the accelo 5l1h(ruan)p qb )8,e q/wkyjeration of the object?

  The maximum speed around a leve8rjq/uh: j+ wrggb+ *41 rgik4mb uwr,l curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factrrkgjr ,:g4jmu1 */g8b4uwiq + r+whbors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter t+.k6t 2bhvenlbxpvd52 gve4 v:u)l1 of a bicycle wheel ofbge4vut2:delv b6kv5pn v2tx .l)1 h+ diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located f2 id6l 1/-l/nyr lnptr+ do(z0.200 m from the axis. What is the cdl2p+1zo /r(l/-nni l6 dtrfyentripetal acceleration?

  How many revolutions per minute must a circular, rotat f*rsi ysgzh s6g4tq*.a01kf0 ing space station of radiuk ahg. 0st s1 *0zfsy*46rifgqs 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goen5t uw9. e+az bi53u2y 2xuo z:z/lqwys around a 13.7 m radius turn at 96.5 km/h. What is the centripy/ + lbnuuwt3y:izoz9w e2 .quz 5a2x5etal force on the motorcycle?

  A 0.50-kg mass is attachen.b2 x cdvjy,:d to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the strc:2yv b.nd,jx ing 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 strong string and whirled in a vertical fg;qez /nf53 iw3sfg,circle of radius r. At the exact top of the path eggfsf;qfw 3,/zni 35 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 and whirled in a vertical cirio1t(c oddz,gsq :6 dn13x0u; ii-rvucle of radius r. At the exact bottom of the path the tension d(0v isoirc:n3, u1odut;x1ig q- dz6in the string is 3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 zuqh;blc9;ch,er32 )v f g;rcm/s experiences an acceleration of 4g when pulling out of the dive. What is the radiuzcg ru9c3b;;cel2;fq,)v hrh s of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center ot -5ynkk 3l/wlf the loop is beneath him) of radius 3200 m. At the top of his loop he 5k ly/3wlk n-tis pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can sta*c5tt wu, d+vxnd is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 v*5txt+,wd cu m/s?

  A car traveling 20 m/s hd*y*5csvc6 dop2v1xrounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can yh6p* *ddv5cxcv21so 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 curve of radius 50 m with a speed of 20 m/s. The im+dhbahq6:d g5 (fqi)j6q 6s0lu: kfcentripe0(+i5u 6a q:fqsim 6lkd:jgfh6 ) bdhqtal 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 speed of 14 m/s. What must6g83s9 n kxics5r lcp/ be the minimum coefficient of friction between the tires and the road for the car to make the turnl i9 8r5kns/3pcsx cg6?

  A car is moving with a constant speed v around a lt*eo0ll 1 1el rwzj25wbfd22-udjv8 o evel 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 2d1zvtowd-e 81f2l l5lrb2*o jw0ujestay on the road?

  What minimum banking angle is required for an O7gmdb.h4,*v nuufy, rlympic bobsled to negotiate a 100-m radg 7r . hbuud4*f,,vmnyius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a b 0ula91as.7 j:wl pldwobsled 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 radium lkw+v9qya rz8;; sciqzh:2t m18k*rs 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atrh d+: o7p2qhw0xbix) $45^{\circ}$. 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 uniforv+o* bz6w f1+o4eknqpmly in a horizontal circle of radius 0+n1v 6oeo*bw+zf 4kpq .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 9 lbg-7 w+/8x6jvovfm fybzy +the pit 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 fig8-76j xvz+9bb fv/w myfoly +ll 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 consiz,:y do/w ;cbksts 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 onw (5vnej6dbsjkc558 l the Earth, due to the Moon? w5s8e v5cbn (5jk6jld The 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 force between two massoehqh ;1 m .j*x2dqd5pes is F. If the masses are moved to *p2q; oj1dqhxh5.ed m half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from thoe3ol ykrq .,x)ix;w+t*e7x we Earth w eqt;+3r i)x7 yw,w .kxoe*lxoill the gravitational 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 is 97lbeq3 *v (7yotsrds2tmme2$7.4 \times 10^{22} \; kg$ 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 fy2) .vdxpvn*m.wwpk 1 or a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gr.m)ydwppnvx2*1v w k .avity?

  The radius of the Earth is R. At what distance above89m zihi t:ps3h6 cj.x the Earth's surface will the acceleration of g8z.ipicm3ht j9:6sh xravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 m4: pvocp *g*otimes the radius of Mars. The acceleration of gravity of the satellite, as compm:vc 4opgo **pared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's (-kd*-8c hgpwzr x.qocenter, the acceleration of gravity isx*gz .q- d (8kr-hpcow $32 \; m/s^2$. 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 radius r. qeg ulie5 *5,(nqozy-If the object is raised to a height of 3r above the Earth's surface, what is its weight? ,5e -g(lq*qoz5eniyu

  By how many newtons does the weiaq621 rqn 2:u j5w )mdwiqeti8ght of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the wqd :6ia5u)mjite28 qw nq 2r1Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 4xp, z q7tqsl1100 kg is at a point 3r above the Earth's surface. What is the satellite's weixpzq7 t 1s4l,qght?

  A spherically symmetric planet has four times t f rz)g7nhyv29d/fsu.he Earth'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 on the surf9d ) h2s/gr.u yf7zfnvace of this planet?

  During a lunar eclipse, the Moon,9;ua3 ;t(7dyaudkle s,habj, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. T; ,ab(ejduy9 kuast7dl;3,ah he 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 td/;sq (q n6atfransported 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 circte3l( jco 6n khl2,u ei1ccj4.ular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the j 2lecu63 l.j(,ne c14othi kcsatellite? (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.,h o49w u;x2c81zecoz8cmcsa+ it just skims the surface of the Earth). How long does it take to make one revolution around the Ecwcc9 2 o+1am8u c;4oz sz8hxearth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circula h1 0kwz5mm(dtr orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Ear1m0 thzw (dk5mth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameterpq*n otyf3rg1*e1cx( 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 pl+5u,e mmu ,; 9q-/pk wf)hzp0l qbvwttanet 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 radd18( cyr yy7 m8cbr)dmius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete ocb8y y m718d()ymrrd cne orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isb)kf z3:6yqar $7.78 \times 10^{11} \; m$ 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 once. What is the avemx,s/gwp:3q4ujvw,co6 sid 0rage distance from Jupiter to the Sun? (The distance from the Earth to tqs/ gvc ,s36:jdpwm ,4xouiw0he Sun is $1.5 \times 10^{11} \; m$.)