Is it possible for an object moving with a constan:8a1djtm (ug 1nah6e , yqtr)c s1yv*mt speed to accelerate? Explaic1sm6 yn h8dtv: ta,*(1 ua1qm)yerjgn.

  Consider a particle moving with constant speed such that its accel1-xelv cihi;z* 3gp5 weration of constant magnitude icvw 1;*pxzhe il53-gis always perpendicular to its velocity.

  An object moves in a circyc40 lpngs-0 tweq bldqxe 3o826 z6f:. -xuegular path at a constant speed. Compare the direction of the object's velocity and 8by2lng0ex s l0: qu e6.g -wotcq34-expz6 fdacceleration vectors.

  When an object experiences uniform circular motion, the direction of7xqn6 r62r,zy) prg s0lx3 say the accele y,70nry r26lsqa)6gz rxx3s pration is

  Consider a particle moving with constant speed suvuai;kk5kqdms 83 ;pu(9 n/lqch that its acceleration of constantaum9 v3q8 ;k5npklqd;u(ki/ s magnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving wic0n n,0wpou d*y:w+ czth constant speed in a circularc uw y ,nc*pw+00:onzd path experience?

  What force is needed to make an object move in a circ:ykxx5; nv rui *:ws(ndb6bjf:-so8 ble?

  When an object experiences uniform circular motion, the direction zad8k b+.qbb( of the net forceqab(.zb d8kb + is

  A roller coaster car is ot 051t bi6yn.olva: sts( yf0mn a track that forms a circular loop in the vertical plane. If the car is to just maintain contact wb06ov.fyay tsnl01(i t5:mst ith track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = qc mbq.,( djor9g; /:8rws wlrM) is on 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 the top of the loop, what is the minimujrw:/gqcql9s( ;mrwd 8,br .om value for its speed at that point?

  A pilot executes a vertical dive then follows-*q4dr qk,r ov a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him is,rov k qr*-d4q

  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 :jlyxa3;y+k.my-unm9*zhm o bv tr75 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. Then it goeshnkvx34bx0b - around the same curve at half of the original speed. What is the centripetal force on the cvkhx43-bn bx 0ar as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve 3 vil/w- v,barof radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. ,-rwbia3 vv l/ 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 radius r withewo2jw l4, ksl, 1 3iuw3gemc7 speed v. If the road is frictionless due to ice, the car can still sl423i,13o k7w jwm gl,eewucnegotiate 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 the same angle, butjir0a 9oc9 b81ofc x,c one has twice the radius of the other. The safe speed (no friction needed to stay on the run),oj0xoi9f9a 1cb8 crc 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 bobsled track is not consisf w sy,sk*85tant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go low sfsskw5y,*8ier coming out of the turn. Why do they do this?

  Is it possible for an object moving around a c0 a7;ab 0en :ncwcl lk78n8bwtb 88zddjv9w9eircular path to have both centripetal aw9w9 vdt; nl8 lcdbb708nez naeb70:8 wjcak 8nd tangential acceleration?

  The gravitational force betwe: blm mlbhv6-1en two objects is proportional to

  The gravitational force between two objects is inversely proportio u4xucjk; 86 itzi4a3mevs0 /rnal to

  Two objects attract each other gravitationally. If the distance between t,pkq(8 ;qhi-pjnl b/ft 7)by rheir centers is cut in half, the gravitational for( fbk8prtbj7n;hp ily-q )/q,ce

  Two objects, with masses d ounc0;u1y7 o$m_{1}$ 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 mastpa .t91ie5 wwses $m_{1}$ 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:59xghpjv8 vf universal gravitation.

  Compared to its mass on the Earth, the mass of an object on the j(x8qywsf.0d 4k*o m uMoon is

  The acceleration of gravity on the Moon is one-sixthg1*i m 2bhb1nr what it is on Earth. An object1 2nb*gir1 bhm of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from hs)uex+pa4y. the Earth's surface, the rocket's weight

  A spaceship is traveling to th:m -jkrlbrc ,4e Moon. At what point is it beyond the pull of Earth's gravi :,r kl-m4rbcjty?

  Suppose a satellite were orbiting the Earth just above the mjw 1+hbwb+j0;yt. gsh;ns k;surface. What is its wj.jhy m wbhsngt01;s+k +;;b centripetal acceleration?

  A hypothetical planet has a mca+h-8jhp.+)gkq4 z d c1it 5el quewga)a51lass of half that of the Earth and a radius of twice that of theu )8pqc-.athqg+ wall4z j+d1e ig55hkca)1e Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of g2s-s )hog2alq xadvh 0d zejn71 xv, 0*hz;m*yravity on the Moon is one-sixth what it is on Earth. The radius ofv dy )h,zs *2xv 0z 1onqg;exha-7l2madsj*0h the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same ;l97rdo 9fy i(ix) etmsurface gravity, but planet B has twice the radius of planet A. If planet A h)( yir9lx9 mto7 efid;as mass m, what is the mass of planet B?

  Two planets have the same surface gravity,i0 uw 2+q .ahp*gdvcg/w7 znx, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet B?7 xai v.2,*wpcgdn hu/w+zgq0

  Consider a small satellite moving in a circulz 35;fb3x gw ap/nuy3,r/ atbiar orbit (radius r) about a spherical planet (mass M). Which expression givesb/yf/3 3npb3,t;ax5air w guz this satellite's orbital velocity?

  Satellite A has twice the mass of::d,0re q gtwi satellite B, and rotates in the same orbit. Compatq0i:w gd, re:re the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compare t/7kyx 6rgwqk8 q8d9nahe reading on the scale toayk9 n6g/ xw7k 8qqr8d the person's true weight.

  Who was the first person gmcq/xc )p 1t-to realize that the planets move in elliptical paths around the Sunp1/cgq t xm)-c?

  The speed of Halley's Codj 5wbopp7 2ub/1ac oht543 wamet, while traveling in its elliptical orbit around the Sun,5awot bh/p5 o7ucwa143j2dpb

  Let the average orbital radius of a planet be R. Let the orbital period be(gk cgn6 7so9e T. What quantity is constant for all planets orbiting s769ecn(kg gothe Sun?

  A planet is discovered to km5ak; npmn .:/xh4hxorbit around 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 5h m ;nm a:p4/khk.xxnto the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as kvq,gps o ;kq0h5mg u.nj16 4lone "astronomical unit" (AU). An asteroid orbits the Sun in ou.kq0;nsog6kv p qjlh 4gm15,ne-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.bszbh+me 7: h/xacv/)

  List the four fundamental ejesb3x ji0/j0 gae,89ta wv- forces in nature.

  An object moves with a constant speed of 30 m/s on *2 *s50:n qwvxs f0sjoxh rn9aa circular track of radius 150 m. Whq0xrnnvf5 *ashs2 x0o:s jw*9at is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What i0w o24wdo*y2t:wbhg t s the maximum speed around a curve witd*0:w wo2wtygh t o24bh twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter ofohp b4x1hp.1 p a bicycle wheel of diameter 70 cm when the bike is movinx11p4h bppoh .g 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0txt8xhg7g 6c3 /tw v+c.200 m from the axis. What is the centripetal accele+wc83 / h6ttg v7xgctxration?

  How many revolutions polmt3, ixk5, ger minute must a circular, rotating space station of radius 1000 m rotate to prool x5g i3k,,tmduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1 r olr3wjz2y04j5t )ks3.7 m radius turn at 96.5 km/h. What is the centripetal force0jt krr2j l)sw543yzo on the motorcycle?

  A 0.50-kg mass is attached to the -qw in ,g:h42qu b5sbiend of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if th:,5b24g-s iibun wq qhe string is not to break?

  A stone, of mass m, is attached to a strong string and whirled il(jz 0 9 hodl.mj,pe fe6sfmr-,-xx9qn a vertical circle of radius r. At the exact top of the path the tension in the st ef lxhqdez90x9(r 6o-jpj lm-sm,f,.ring 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 strr3d m1wfh8*iw9c uy3 5bhb9suing and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's wei hcwdyhsu3 98 1fbrb3uw9i*5mght. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out5;z(o e 7sfqdifhzl( 6 of the dive. What is the radius of curvature of the loop in which the planelo6zizfsq(; ef7 5d h( is flying?

  A pilot makes an outside verttmj.g0k3jn e5xx+ *dk ical 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.n5x mjx0j+kd et*kg3 seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about sevejxbf7(syh c mts44/3l h.q9 8pu6y -n+vwnn gon times his weight. What is the minimum radius of curvature that a jet plasp6qvym/lnxh+3(4 . 4 nnbtu -o 79yhcfsjgw 8ne's pilot, 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 /(kt)d vnv+umr62i 90cuc qux curve with the tires on the verge of slipping. How fast can this car round a second curve(9cu/kvr v+cnx0u 6q )t2miud 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. g7mo r 8(psuqanr-d e/hd:6z1The cent( 1m qpr86d d-z: gsuoer/7anhripetal 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 atz )*d0bba5ff/h-k k9u-vsn8f;usm y m a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road 8 zf fm)ah5y u*vssu;b0fmdbnk/k 9- -for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coeffici*,iu+dsha 8rzz7uu j.i z;p2fent of friction betweehpiu8rj*,da z.i ;u7u fzz 2s+n 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 for iysy tny7)8t3 an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore n3t8yy )7i ytsfriction.)

  A horizontal curve on a bobs qziy/(h;dyd tr/um1 )led 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 anj3--y) 7nc s,mde*sodr:bxer angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banvg m.jrz9xx3lsu o*z/9*bx9sked 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 enp2d28(zb gdo ks+(prw d of a string is revolving uniformly in a horizontal circle of radius 02r(bgs8 z2 d(wkd p+po.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 accelera/bzth;alc ib( 2h8s6q tes at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular trac lb6sbtha2h iq8/z ;(ck 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 proton of mass usk 4a5imaz ,un9,y.j$1.67 \times 10^{-27} \; kg$ 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, due tobs 9wm xb e) -fd/kw(j*uex;n, the Moon? The mass of the j)b w *em ke9u;xnsf bw(-d,/xMoon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force +)hpv fwuyfay 9wu n36n)q84mbetween two masses is F. If the masses are moved to half of their initial distawufm4npy8 )vyuh3 9 nq6f)w +ance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distanceg;gm)(y h4o ba/m6 kefuc2v4p from the Earth will the gravitational forces due to the Sun a 4b46g mhvo/m2 ecku)(gf;pyand 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 ij*9:pd ibl.--neh ie5a7 khmss $7.4 \times 10^{22} \; kg$ 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 Earthjw1*ywoy :g */h9oanh9s:kq t equal to thya /o9 k1:thw*9wo nsg:y*jq he radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth'sy, ya 4w1hb oq)5q msy/fam.u/ surface will the acceleration y )h/4yy/1wsuabq.m ,qoamf 5of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dilqqb b6vnetvs7 p2 9u+ h94y.istance above its surface equal to 3 times the radius of Mars. The accelerati4 b7v qe2npiqbh.y6t u9+ s9lvon of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the homk92j 4x b0usd .lu*,:/tuapfm6cv acceleration of gravityf20 t*6d/9mokc h pv .4m:uja,uu slbx 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 surface of the Earth. The Earth has radius r. Iuru0v azt5:l z2/ h cxxozk38*f the object is raised toux 03okt * 8lrxhcza 5:vzzu/2 a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the q1gx ugv 62mcqo+31nf jv9t*ws w)+nf weight of a 100-kg person change when he goes from sea level to an a1n2vqmgt qgu)*+6ffv ns3ox 1cw9j w +ltitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite vc0qq9/fd8p kvq9ln. of mass 100 kg is at a point 3r above the Earth's surfacecvnk9 q. 8qvfp0qd/l9. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's ma3sqgj6vg;v qf d5b3,kss 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 surface s63qq5v3 vbg d,f k;gjof this planet?

  During a lunar eclipse, the Mo3rj4 kbotbrcl-a8 +qo0)urm/on, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Src 8b4uklb 3j arqmo-+) t0ro/un. 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 kv8*k z64qde wto 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 mv.e9 )b/su2 aqhel*hcircular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth is 9. m ue)qhe/alvbs2h *$6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., rr:mwv-p(9)yca vk +rit just skims the surface (r-v mv+cw y9)r:akprof the 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 circuly9liqo,m, 0jzar orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. y,oi m lj9z,q0 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 d ,xwqn57fja0s cm6s 9diameter 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 platkk1k 1qoo, 9r b5+ tyqo1c6crnet 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 orln0 qixv mrui/vyeu-q58g31 f9y0 5mibits. Moon A has orbital radius r, and moon B has oq59en10u vmm i5yqu8v3g/fiy irl- 0xrbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isi n:8s hhvrt(6 $7.78 \times 10^{11} \; m$ 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 zvrr6 8 w2kz-zzkl 0.bc8e zr0years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from w8c 0rzv -. 2r6kz0ezlk zzr8bthe Earth to the Sun is $1.5 \times 10^{11} \; m$.)