Is it possible for an object wppqcab .y(3 -moving with a constant speed to accelerate? Explaib- y(wpq3 .pcan.

  Consider a particle moving with constantt zev9* fmd7 7p(yltf* speed such that its acceleration of constant magnitude is alwayyf 9*mlpfve ttzd(7* 7s perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Comparefmft)l 66-go z the direction of the object's velocity and acceleration vectfo66f tl zg)m-ors.

  When an object experiences uniform circular motion, the direction of the a,1hfm;gex.exd z /9 mjcceleratio /jm;mdxx,. e1gzfhe9n is

  Consider a particle moving with constant speed such thatdx75 j.ukw o4qs88ig z2 l1gpc its acceleration of constant macl8ixp 8gq1d wjg74ko.25su z gnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a circu79iy acxi39w1az7 eunlar path exp ii7aax9zec9wn3y7 1 uerience?

  What force is needed to make an object move in a circle?hrkg ruq 2vvex308*u+u8l/ es

  When an object experiences uniform circular motion, the directe+8lx)s+ n e-p(vxompsb-25 8io fmmaion of the net forceim m pxvofx)-8e+-mlebs (p+ns 8o52 a is

  A roller coaster car is on a track that forms a circular loop in the vertica 0 v/qxn k(baqnt-j4m:l plane. If the car is to just maintain contact with track at the top : mq4n (nax-q v/0kjtbof the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is o-0bg 7 hnogfl:n a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the0gf -h7b gnlo: 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-/g9n +-r6mdz.4; gb :lg gn,nircjaspcircular arc until it is going straight upansm:cg;g nb j-zg4 prl6 rd,.i/ +gn9. 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 wit83 cvs5dzki4b/7scurve 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 of radius r at a constant sp6kryr: refy3 -eed v. Then it goes around the same curve at half of the original speed. What is kyrrr 6 fy-e3: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 constant speed v.z*d bo-jbo:yol4dkjvfr b61z f( /c.: Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around thb:rvz4zoylj-fo6:*bf(/ cjd d k1o. b e second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. 94umzpq z kiz6 plq,zhbz q,51)+nkj9 9m as5gIf the road is frictionless 55pmm,z z9ulz9 iz1 k,b6n9qh)z sj4a+gqkpq 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 banked ar0qm d;)9sq nd+/d( so(fc7hye3 vgbvt the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for+( s; 3)r9chqefo vd(bgm q0/dsy7 dnv the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a ,gdefl8c/opm(x3:o t 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 tt3m:xl/fg ,ceop (d 8ohe wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an objekb 5scp 86,jbxct moving around a circular path to have both centripetal and tangential ab b6 85jpckxs,cceleration?

  The gravitational force between two objects is proportional 3w+ (t6;w pij penxxrb+ c0gip ea8)+kto

  The gravitational force betwvesecy d quae-b nx94l; g)sz4:n1. 2neen two objects is inversely proportional to

  Two objects attract each other gravitati35w u vhxoi)ys6 hoa9-onally. If the distance between their centers is cut in half, tvuh5-ix3w9h)oyao s6 he gravitational force

  Two objects, with massesqsi bvk0 sb5osfy fz9 2.*8c1a $m_{1}$ 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 mav3lxhl)h;k ; ssses $m_{1}$ 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 unih rffa,g 0(;as4.vzwmversal gravitation.

  Compared to its mass on the Earth, the mass of an objei:fx3kyrom7 4ct on the Moon is

  The acceleration of gravity on the Moon is one-lphm8i, lacfa6ni9 63; ckclj0y7x-lsixth what it is on Earth. An object of mas-alphl 6;c380y,a lcj6 fk ni7i9clxm s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fromm ofi q43tqb8q9;(y *ts.y txb the Earth's surface, the rocket's weight

  A spaceship is traveling to thej/ cc 1we8nbq;w5id yba+7g 9a Moon. At what point is it beyond the pull of Earth' 5nwae+iy/ cbjqb g7wa;cd819s gravity?

  Suppose a satellite were ofh .+9t 2ps xfupso0mdd 0g6gwc71p-u rbiting the Earth just above the surface. What is its centripetal acceleration?w -m79fpxggdp ocud.s2 h6sfu0 p+t01

  A hypothetical planet has a mass of half that of the Earth and a radius of tw i:sm9pf/,vvvice that of the Earth. What is the acceleration due to gravity v 9vfivm:p/,s on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of q -jz psjzo2tmxhz*v(.9hv lk hb/f+on38.0 fgravity 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 Moon's massjtx3fh29s.hf-l0mzq z/zh.j* (o kovb8 v+pn compared to the Earth's?

  Two planets have the r68g a9tngi3q qww2b0zb k.(lgc n+u9 same surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what ngg8(n +grwk96bqt i20b3 qlu9az.w c is the mass of planet B?

  Two planets have the sam7gfbamopw9 t8u57f 6ee surface gravity, but planet B has twice the mass of planet A. Ifwpfo7 f96mg5b7t 8uea planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r)jl*dv pqnhe0;e-i b79 about a spherical planet (mass M). Which expression gives thiedvbehql-90;*7 n pjis satellite's orbital velocity?

  Satellite A has twice 6*,kzj; f nxyfxs*x0xthe mass of satellite B, and rotates in the same orbit. Compare the two satellite's speed*yx s;f6zx x 0k*jfnx,s.

  A person is standing on a sz0( bbtcgu8a 7:5d hmicale in an elevator accelerating downward. Compare the reading on the scale to bc07hg (: atd 58buimzthe person's true weight.

  Who was the first pe gl le9u*)ode5fv b53erson to realize that the planets move in elliptical paths around the Su eve 5)du l5legfbo93*n?

  The speed of Halley's Cls0005(n/xw f ;yculfb ( emthomet, while traveling in its elliptical orbit around the Su(fllxcmf h;50et0(0 u/bwns yn,

  Let the average orbital radius of a planet be R. Let/c/zv.i 4-q shg:jwcy the orbital period be T. What quantity is constant for all planets orbiting the Sung/hc.- y:ws ijcqzv4/?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with*97 san;)z-q culorgy 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 bea s-9orz c)nyl*q7u;g, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as jj pz0:tmgxeb( r+0.+3 kbcnu * 2razdone "astronomical unit" (AU). An asteroid orbits the Sun in one-thi0nj2*jt0c +k+ru zbz r mag edx:.pb3(rd of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.v zhk8 ivt.9k1nc*ai iv+9+ qj

  List the four fundamental forces in na:k3z xjhvp8 w7 ceon.)ture.

  An object moves with a constant speed of 30 m/s on a ciotjyi9f)fg*w ,3n6 rs rcular track of radius 150 m. What is thefi,noj 693w )tg rs*fy acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Wh*ketrxudj+ 7y/x; xe.at is the maximum speed around a curve with twice the radij7;ud e*xex+ rk/ tyx.us? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimei;4 o:tpaj t3h/ ei6ovmt;4ceter of a bicycle wheel of diameter 70 cm when the bike is moving/a; th4pttie4v :mji;3o6coe 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/fz )-(eg pwhh*s is located 0.200 m from the axis. What is the centripetal acceleratioz*phw e-(f gh)n?

  How many revolutions per minute must a circular, rotating sp923z7s ueff5l4+ -w bqzkxmrtace station of radius 1000 m rota- 3 72fflz4 +m9zt5kswrequbxte to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.ro )jar,hc0h04tx9 uy7 m radius turn at 96.5 km/h. Wh yth r,9j4ru0xo )0ahcat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The sys a:o:uhww8(ietem is whirled in a horizontal circular path. If the maximum tension that the string can withstand is :8(wh :uoeiwa 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 /ljrx2iqenz +i;, ru7 a vertical circle of radius r. At the exact top of the path ju zq;,/i nrxer 72l+ithe 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.yyx.vl*d (s w vertical circle of radius r. At the exact bottom of the path the tension in thes.vl(yd x.y*w 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 accet0yvdy 8pxf)zbc, i6 9leration of 4g when pulling out of the dive. What is the radius of curvature of the loop in whi9pv 08d yxfty c,)bi6zch the plane is flying?

  A pilot makes an outsq 8-fhs x-lu+yide 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-huf 8slq -yhx-+alf of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What is w8 w,wxg u3s63x f)ejvthe minimum radius of curvature that a jet plane's)8f xu w6se3jxwvw3,g pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s auw2gjl.cn)or-c9k l wqkq):(qt :p/rounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 3gu: -wwqcq(p)ak2nl9t :oqkcr.) l/j 20 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat cu6q4wu/fy q-y .jf w(j.ar(ngvrve of radius 50 m with a speed of 20 m/s. The centripetal fn4 .f-qwwy/ aqj y(.(6 frjvguorce 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 (z ) 6*j1emmx xbxcro*must be the minimum coefficient of frictionz(mmoxecxr b* *6 j1)x 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 cu+ z -3b9vnhn 3;evehhdy(h(sl rve. The coefficient of friction between the tireehb h3 (9( snved+ nhyvhz;3l-s and the road 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/vgjfc zn*wuj0s;m8 9q(;xu c4 ry(bc Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignorexzjcf 4r gvn uu8m;s 9cqjc *by0((;/w friction.)

  A horizontal curve on a bobsled run is bankcq)o 5b7jw 9v e5n3sop,*vwmked 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 aff ua63l+b9m5 o- *crcx vhfm;n angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at op(7undm/ n,4f(h 0(tymgqe r$45^{\circ}$. 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 eai)w vu*5ua:0as52s)pc4vi ncuv t7o nd of a string is revolving uniformly in a horizontal circle of ravp0vc uuss 4va) )uai5* cti2o5:wn7adius 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 puun(knf zn;1. it 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 fill in numu1f(kuz;.nn nerical 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 masm6x 9t;kv-sh js $1.67 \times 10^{-27} \; kg$ 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, duj k wtiu +/eq+3+tppo-e+ 2time to the Moon? The massw j q/tt+otikmp3-ei+p++ue 2 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 masses is F. If the masses euu p83h 1f;ed+(cc nlare moved to half of their ipc( 8;luc+fude13 nehnitial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at wwl59r+ fsn+icbnx- r6hat distance from the Earth will the gravitational forces due to the Sun and the Earw-n9 l+f6rc+ ibxsr5 nth 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 xx;2zvwme2n. $7.4 \times 10^{22} \; kg$ 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 ah4 +rbilr) hmnywav0 o. p*x:7 distance above the Earth equal to the radius of the Earth. What is her accelirb:h m )0ry4+nx l7p h.ow*vaeration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface tv t172eg.ozx will the acceleration of gravgzet1o7t2x .vity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its svdle7+b7 ut:/v bdu -rurface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration o vetldv:/b-r7ud ub7+ f gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of g km:,ko,p*ycgravity is,cmk:kpg oy,* $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N onanz( :.il xx2o the surface of the Earth. The Earth has radius r. If the n:.xaoilz( 2 xobject is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chana2o01 ggqarf 3ge when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth ia 12 orfgg3aq0s $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r c*5a jsw-vcx 6kc1rn63,d*lwg pp3leabove the Earth's surface. What ird5w gls*6ackvnw, l*16p 3e3 cj-px cs the satellite's weight?

  A spherically symmetric planet has four times the Earth's y eyz7asv5;d2mass and twice its radius. If a jar of pa7s;eydv 52yz eanut butter 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 Moon, Earth,slkb9h3k gs 0o.5o z.u and Sun all lie on the same line, with the Earth betweeso zuol3k b.05ks9h.gn 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 Mr6bw scca3 oxqod .ej8d47f8:oon.
(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 (iyjeiea71q -ieq3zs cd 5x;: 7y.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Eadciyi3 a x1q-;75qezy7seje: rth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular oxkc)uzafl 4p :x6fy+v5rl95 zrbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Eakf x69:54y5pzrax +l vlfuc) zrth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the sux7nh,cfh k ywqi3s06q:er415- pb urrrface of the Earth. It is observed to have irqquf ,rx5 p60cn:e3hsbh yk714-wra 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 Jub49 d6uscw(sc piter, 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 rw5vu3 8i6ndob adius 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 ne s iimk.: bi*q1q5:dhyarly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. si y1 dqm5.:qibi*hk: Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is m 6fg(posv4,a mn+:ew $7.78 \times 10^{11} \; m$ 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 7 utno(va8b do9e2 gn1ha u:8eyears to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun ieo(9 n2 go87thn1e8:ua uvbad s $1.5 \times 10^{11} \; m$.)