Is it possible for an object moving with a con6dl 65 ojc 6a: 3gczfkqck93z:su)rmlstant speed to accelerate? Explai :63aq6m 3cl uo)9:zs zldr k6g5cjfkcn.

  Consider a particle moving with constant speed o;y63 (tomds puda+ 7jtyql06such that its acceleration of constant ml6y0y7m a; q+j 6p ttd3osdo(uagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dir s+vk, m/td rck66p3euection of the object's velocity and accelt3rmdk,u6evsc p k+6/eration vectors.

  When an object experiences athf :n 7zw.:b0 vgn:ouniform circular motion, the direction of the acceler::hf: vb7tz nonaw.0gation is

  Consider a particle moving with constant speed such that its acceleration ynerh+m7l:l:po/uj , of constant magnitude is always perpendicular to itm r jyloe7n+ h:/p,l:us velocity.

  What type of acceleration does an object moving with coxj:l)h9 al3zx nstant speed in a circular path exper9lh3j xx la):zience?

  What force is needed to make an object move in a cy fru*mj(s6-c4v eb vij10p(fircle?

  When an object experiences un gi3fb;sg /1qriform circular motion, the direction of the net forceqbg/r gsi3f;1 is

  A roller coaster car is on a track that forms a circular 3l e e/j;5odibtno* q(mrq1)z t67cefloop in the vertical plane. If the car is to jqc3 7;o15nfm(ol) t6berteizqj *de/ust 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/cadk1 wwv v11 forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain vd/1wwkvac11 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 k5od qm0+rd* vtmb/)f arc until it is going straight up. Just as the plank +r0tod 5*v/)qf dbmme 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 curc)uica ,q ot* m;8k9y m:xtfg0ve 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 speed v.a .0xwjc-zs5z/4 gn wjcm(7dk Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second timed jjnz0s- .5/m7c gwa4z(xckw , compared to the first time?

  A car goes around a curve of+c tsy) weq+(2nhvvk 0 radius r at a constant speed v. Then 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 curve, compa( 0kt2c + )+eqvvywshnred to the first?

  A car of mass m goes around a ,yz g+8(dv2 -buhbpat banked curve of radius r with speed v. If the road is frictionless +u h2b-dp(8bavtyzg ,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 at rmx omj ob:-.;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 smaojx.-:b mro m;ller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Oly2rk +e(5g mqdjmpic bobsled track is not constant, but increases upwaqmr2ekd j+(g5 rd 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 this?

  Is it possible for an object moving around/ .et6ewdxev 6 a circular path to have both centripetal and tangential accx w/6ed.etev 6eleration?

  The gravitational force between two objects is pro6u:qnp6 qrms9-y /e jhportional to

  The gravitational force between two e cdp :nvsk. tf )9e3c1zr;e3dobjects is inversely proportional to

  Two objects attract each other gravitationally. If the )0o2gq 9htuwc7y*qn2z y4beidistance between their centers is cug7*2w bqqyoehnu 42tz9) yi0ct in half, the gravitational force

  Two objects, with mai hiwqt9+y8u3sses $m_{1}$ 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 mah(ii/qhv p5lod +sg : ng54k*psses $m_{1}$ 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 univk 4awo )r8yzb(mvaivvor/ 3 09ersal gravitation.

  Compared to its mass on the Eartflk2 (srko r9)h, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An ob.2 ituv fo86lvjefvov2u68t. ilct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket: *ri2 wc*gt.cw6ta ,vrb chs,'s weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull of q d+9vtph3z: 1uetg wgx1g)x: Earth'sz t1xp:3vgtgew 1 dq9xgh)u+: gravity?

  Suppose a satellite were orbiting the Earth just , ekhc,j ;6fxiabove the surface. What is its centripetal accelex h cj;ef,ki6,ration?

  A hypothetical planet has a mass of half that of)vc w44ud50( tz :d)jdjl h7l)tchvm-mzi3ez the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the accel5tz0lvv7(4hdmdc uiz 3j dc:t4w j h-l)m))ezeration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-six(9xgvzi,(-mi f9tucy3tv(5 zk xcft5pb: +nath 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 t5pb3ktzv 9 a, 9ifcf+y(x(m5vuctxz(- gnti: he Earth's?

  Two planets have the same surface gravity, but planet B has twice thx,/8yjwlgk cyu7e)2a n3 c8jfe radius of planet A. If planet A has mass m, what is the masscg8ck y3 7w2 jyxjn, la8ef/u) of planet B?

  Two planets have the same surface gravity, but planet B has twice the massf:zgt 1yw 7j8ne4e2 ml of planet A. If planet A has l4wy2zf1g7 :n e 8metjradius r, what is the radius of planet B?

  Consider a small sate on;dl+opl2;nqe /vb0b)i 1ipy)l aq ,llite moving in a circular orbit (radius r) about a spherical planet (mass M). +y1;aqle i nbio;)0v p2qdpbn/,ll)o Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass o:(m6yeas eh r4f satellite B, and rotates in the same orbit. Cs my(a:64 hereompare the two satellite's speeds.

  A person is standing on a scale in an elevator accelerabs 6a/f a(ygrhfj6b56:iq 11s)tu dqg ting downward. Compare the reading on 5 qj(6q rbyt1/s:)a biuga1sf gdh6f6the scale to the person's true weight.

  Who was the first person to realize that the planets ni t uny1x61umpp; 0fl55zvn +move in elliptical paths aroi;p0u5 6lzp5 n1tf u1myv+nnx und the Sun?

  The speed of Halley's Comet, while traveling in its elliptical ov 7-s3 minm(uorbit around the Sun,si(on7vm 3u-m

  Let the average orbital radius of a planet be R. Letbin85)gba; urw1 oez1 the orbital period be T. What qua 58nbaziw u b1gr1;e)ontity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in thxfaf ,/pe3an6 :ldfc /e galaxy Andromeda, with the same orbital diameter as the Eara cfa/xn,3p: fdle6f /th 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 the Sun is defined as onah/r 1 7 dfvk5o1)llxze "astronomical unit" (AU). An asteroid orbits the Sun in one-third 1avlhrol/d17f)5z xk of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.s3ve3m .pynm4 3q- rgl.csf0s

  List the four fundamental f9q,6:z gexp z xjqb4 qwd/r5h,orces in nature.

  An object moves with a cowo l)vs4n8fi0s0 r2um nstant speed of 30 m/s on a circular track of radius 150 msowniu2f 0r v0ls )m84. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the max-6hgk9s j6kx e7w s2 (rgkk5junw7 ws)imum speed around a curve with twice the radius? (Assume all other factors remain unchangesk26 7(gjrh 5kwexs)kk-j7 wwsn6 u9gd.)

  What is the centripetal acceleration of 5u(k4,r5ifu.jw;f dyy* e*idx b8sq i a point on the perimeter of a bicycle wheel of diameter 70 cm when the eidx sy; 54u wiyf8q(.fk5jb* rid,u *bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200idzp-mk )ic;7b 18tvng q uu00 m from the axis. What is t8)pg0z7;0i bn- dqicm1 tuvkuhe centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station olg sa):o/*a adf radius 1000 m rotate to produce an artifi:*ogl ad)/aa scial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes ar 8/t/v-ggdzn6ef s pd6ound a 13.7 m radius turn at 96.5 km/h. What is the centripetal force ogg6tsp8d/ v /-6nefdzn the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The systemlg,+ t7uv-ph+(m npj l is whirled in a horizontal circular path. If7j+gm,-p+hpult ln v( the maximum tension that 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(7- +ataggnfu strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the a-7fatgg+n( u string is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attz.hgy;xu3rq + m4w +daached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times thq4d x+ wyau.;3gr+hmze 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 out ofm/5mdpt oc,q 2 the dive. What is the radius of curvature of th,o c/mtmp 5qd2e loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the lo) kcckue9*o,z/ wqdxhx4bc2s2 yta e**t:fx 5 op is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal we *x kt s2afeeu:t) oc*zxkc 2,bq wy*5/h9cd4xight. How fast is he going?

  The maximum force a pilot can stand is ab)qh ; og9x5.(66 r6tqjhp twgguq- salout 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 ofu5;r wl)sgh6qth6x g6- .t9 pago jqq( 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horf he)ye *7bp19+ kjn igw+nyd0izontal curve with the tires on the verge of slipping. How fast can this car round a second cu+1wie fy +7kdepn jnb*g )9h0yrve 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;ig4w eb 1zuv- speed of 20 m/s. The centripetal force pro;gz iuw-eb v41vided 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 must ; ,g6txa n2n: u/amu za k(+8q,ntktvtbe the minimum coefficient of fri2nz,;aav nta(qnt,:t+utg/xkk6m8 u ction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed qh(yr w1bxmaf9(6hq6 v around a level curve. The coefficient of friction betwe69r h (h(xqb a1wqym6fen the tires 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 fotft-3k 4k c/ b+jmg r0zq)ghu:j0 7uthr an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding?- 0 kq/ :tk7 fjtmc) hg43tjrb0uhgz+u (Ignore friction.)

  A horizontal curve on a bobsled runrhv mb/r9 *k,rl3:9 rjsro/lh 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 a 9m t/lja7je2d2u5o nun*z +62sfjahcn angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is qwjb jxs 6924xbanked 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 the end of a string is revolvi-y 5 yk4uz nj3,opno-kng uniformly in a horizontal circle of radius nyk43k,z n o--5oujpy0.500
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 race4+ qv.u psqr8v car accelerates at a uniform rate to a speed of 4.vvuq+r48pq s 5 m/s in 15 s, moving on a circular track 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 proo)pt ho jmu7l5(m: engu*h ,j7y+txq/ton 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 gravitatiooyf47lvs2:nyg xi.g m 9x;m;bnal force on a 70-kg person standing on the Earth, due to the Moon? The mass of thexm9i yo:v27sg;gm.n ;lyx b4f 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 betwee ( :d)g1vkrge0tn;2i7m uaiwln two masses is F. If the masses are moved to half of their initial distance, whd tiv0 w:)k1ri e ag27g;um(nlat is the gravitational attractive force?

  For a spacecraft going from the Earth toward thlw+ol gl1j-nx t/(v 0ze Sun, at what distance from the Earth wi0x+/ -ongj l(1lltwv zll 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 ;3oyihv md* 9n$7.4 \times 10^{22} \; kg$ 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 abo*l jo:ut4f8pi ve the Earth equal to the radius of the Earth. What is her acceleration du4op *itfu j8:le to gravity?

  The radius of the Earth is R. At whad u*3c*dl6n u3rlyn 6mqp9p0l9bj kg)t distance above the Earth's surface will the acceleration of gravity yrplubukl)npd6d9cl q**nm 3gj 3906be $4.9 \; m/s^2$?

  A satellite encircles Mars at a d4s3 2 4bedaicjistance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration ofje ac2ids43 4b gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration ovj1bznc *61 ,stmpu1wf gravitys1vwzt* 1c jmp6nub 1, is $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surfaceoavv 9limejy -6.bd;- of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surbvi-6j l e.ad9;mv -yoface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goek9zvur4z . c7jr v1/wjs from sea level trc7k1r.j 9wzvuvz 4/jo an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mggrs x27,b 1xqass 100 kg is at a point 3r above the Earth's surface. What is the sate2 g7bxx1rgs, qllite's weight?

  A spherically symmetric p, /rtvna z2;wilanet has four times the Earth's mass and twice its radius. If r;i nwv, z/t2aa jar of peanut 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, the8(a2r qtnv lo) 63a tn(fma1sm Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a ma s8mmrnlaq )vf(oa3tnat(2 6 1ss 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 ballr7;f vhr-,dzjzbb)6i is transported 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 the Earth (i.e., it juyco2o)r9bs:ma te 4d4st skims the surface of the Earth). What is the speed o 2)mycr4:a49obde ostf the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circu6 *c h6ap7gr 7*jrfj 1 no2z3yz )onfz,bq:xtflar orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution arozjfzo3 1b)6gt * x, 72 coazrnfqh:n6y* fpj7rund the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above thc1 gq)g7*r io/vjc30lc) rv mne surface of the Earth. It is observed to o7c c/ vvrr)10lcijg3gq) mn *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 vzmm9rh 5c+9b65ufppbj12. naqjh/xof $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planetx vs+ .9royddxe4:hs5 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 orbib7qkpcpbi3k :rv90l(mf * 1t its. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A c1*mvplt0qr(f3bpi7kbk 9 : itakes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ismu7wq 0;e xmaro 6p-2pjx 3f1x $7.78 \times 10^{11} \; m$ 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 averagbz7 k mm3xp:o8e distance from Jupiter to the Sumkx7p :z83bm on? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)