Is it possible for an object moving with a constant speed to ayf ,irb2a 57rb g+:1osqjo+whccelerate? Explaisg7fhwqa5bob:rry2 i +j,+ 1 on.

  Consider a particle moving with constant speed such that its accele1,yd( :sydx ggration of constant magniy g x1sdd:,g(ytude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Cwbi ;4c9x tq:9qfrwx05b* esyompare the direction of the object's velocity and ;:4txbsqq xwc0by *9rfew95 iacceleration vectors.

  When an object experiences uniform circular motion, 1+ ;-qpsnbhe8 wcrfd+cih0s 9f:l,yv the direction of the acceleraf h q-c+s;ye s10bp+ cdh ,8lf9nv:irwtion is

  Consider a particle moving with constant speed such that its accelerat/yu,i go 6jyz6ion of constant magnitude is always perpendicular to its velj, i/yuy ogz66ocity.

  What type of acceleration doe(jm -k 6fhgu+es an object moving with constant speed in a circular pat (f g+6mke-jhuh experience?

  What force is needed p d)jm:61 gzaato make an object move in a circle?

  When an object experiences uniform cirkv5zidv75k .pcular motion, the direction of the net force isivv p5k.k7z5 d

  A roller coaster car is on a track that forms a circular loop in the dtzh/mzu c 3euitv-/si2y*3 3vertical plane. If the car is to just maum 3yv3isu2*e3t -cidtz/ zh/intain 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 forms a circular loo.n zx0--o4jnsa hopa( p (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, whatpxs4-ono -.h(0 naaz j is the minimum value for its speed at that point?

  A pilot executes a vert*q)m.wxmdc8k9fvn (p)rl v iw-(w lw /ical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at mwfl rw9 xvp/i (wm vw(q)n 8lc)-k.*dits 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 radiuskk wovml l*273 $r$ 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 cons*hl/ki)2gl d9roaux.q5 f*v vtant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car al/*ku*5lai2dvfrq g9v. ) ox hs it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of t2 ilv5 tq8y:cradius 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, co8y :icttqvl52mpared to the first?

  A car of mass m goes around aik-ik* 83 *tauzktb/g banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curvek3kz k* - *it8taui/gb 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 xwmmc-; )-abobanked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay w)b-m -comx a;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 turnt5.gg5 bf :mwp on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lowtgmg :f5p. 5bwer coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to have both ciaoalb 3+q6b5entripetal and tangential acceleration a +b3o5l6biaq?

  The gravitational force betdxh 3tb*ht6trl w9tjey -b521xw.+h zween two objects is proportional to

  The gravitational force between two obj1oby68-v e7h xwc0m ezects is inversely proportional to

  Two objects attract each other gravitationally. If t*r 393jixhv(l.b;atzcm9 tty bd1c5 phe distance between their centers is cut ixjdb*1ttm5 c9rap (blc93hyvz3. t ; in half, the gravitational force

  Two objects, with masses *xde anh p.f*0$m_{1}$ 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 masb-cgd/,*r0qc-cqx b* icc.uuses $m_{1}$ 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;d1sf*s z.)ac shj tb( universal gravitation.

  Compared to its mass on the Earth, the manpiy +tf,pm38ss of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. 0h xtsy.,(b t. ahba-r An object of, t s btxb-.haar.y0h( 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's weightuyugukpf; 9c )w/3 ou(

  A spaceship is trave75ip a-lbs ntz5 tyxr+bd98 skx60i c)ling to the Moon. At what point is it beyond the pull of Eartx z5kitp9)xl sbt7s +-diy 0r8nca56b h's gravity?

  Suppose a satellite were orbiting the Earth just above the s 4 s 9bz:z1y5f2zxp1gl9dqdzlurface. What is its cezl4 pz1gyxd:l91 q 9z5bdzs2 fntripetal acceleration?

  A hypothetical planet has a mass of half that of tg6crx 8gzve9 (4h7tpc he Earth and a radius of twice that of the Eart7zc pgg tr(vhc69 84exh. 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 gravity on the Moon is one-sixth whasw;o+-l h4et kgm4s6it it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Eari- mh 46gt+sowe;kl4sth's?

  Two planets have the same surface gravity, butx4 q 4pj.i9 k41rtwomjw,r t-c planet B has twice the radius of planet A. If plaj1 4mcrx t4jqww 4 9ik.rt-,ponet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but pladr2z4t 3aefcl: t8y/b net B has twice the mass of planet A. If planet A has z/f cb 8 tt:dea3r4y2lradius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheric*oo sjzz0f i8(al planet (mass M). Which expression gives this satellite's orbi*z8jsziof0 (o tal velocity?

  Satellite A has twice the+w ;hdw a6iq:82+skuymvp.d a mass of satellite B, and rotates in the same orbit. Compare the two satelw6va+d s8mkhd p.:2q;auwi+ ylite's speeds.

  A person is standing on *i 7lsujei 8tst.4zd-a+yi h(a scale in an elevator accelerating downward. Compare the reaz+hjtal (ii7esi4yu sd*8t-. ding on the scale to the person's true weight.

  Who was the first person to realizb; imb1 tdnf((e that the planets move in elliptical paths aroundm(n (bf;d i1bt the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orb fw j : *pyk:mmqul996kgn*.lkfvju 5)it around the Sun lj: ff9 p*yk 9uk56mlg*m):juv.knwq,

  Let the average orbital radius of a planet be R. *np +rvd/yhm6 Let the orbital period be T. What quantity is *6pnhrym +/dvconstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the gc 0nki e5d.;xgalaxy Andromeda, with the same orbital di.5e cgdxk;ni0ameter 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 fr . -g6* enetnv(akt/reom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits thv*- t eek en6n.tg/ar(e Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.( 06dxqjrtct5

  List the four fundama b sk9 .gy9qrn4x+lzg9wv)s93p)quyental forces in nature.

  An object moves with a constant speed of 30 m/s onyhq( 8olsz a:4 a circular track of radius 150 m. What is the acceleratiol sh:a8(zyq 4on of the object?

  The maximum speed around a level curve is 30.0 km/h. Wha/+nd cwp73iy/ *eyctv. +ok-pkign: bt is the maximum speed around a curve with twice the radius? (Assume all otn .cb *-pye +civ/d/3ng +o:iwpy7tkkher factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a 2r (tyuczcy38 bicycle wheel of diameter 70 cm when the bike is mu3czc r(2yt y8oving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev1zb jn kj,jk5 h548ejg/s is located 0.200 m from the axis. What is the cen,zkh85b5jg 14je k jnjtripetal acceleration?

  How many revolutions per minut4v 24qbw8 barf mv lgga3/1r3mb ,imuoog+k- 7e must a circular, rotating space station of radius 1000 4q1kam -,4+g7bwim 2 blrmgb oag3ov 8rf3vu/ m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aroundoq,c1:j )c:c ygze* nd a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the):1qy,g jc:zod * encc motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whir4g1 sd3 :g* vk+zapbns) oq8dkq8cm,fled 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 id ,4 f*q)km8 b8gcks:p3d1avsz+gnq o f the string is not to break?

  A stone, of mass m, is attached to a strong*rv29ral w s+m string and whirled in a vertical circle of rad2sm vr9lr*+waius r. 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 strong string and whirled in a vewh,r xjad 1:dp9gg 9+grtical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weightj+wg1g,9h:rxpd9 a gd. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g w9xaf9 ey9e 6duhen pulling out of the dive. Wxye9ed6a 9 u9fhat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside ver4hbz q)p4c j8atical 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 on8)j aqpb4h4zc 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 times/;fc *sxh)ekx his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of k/x* ;esc) xfha vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tiree ;l ir 7va48,;3 pbujivgf+wnucd21ys on the verge of slipping. How fast can this car round a secondc4r;biny3 ;pd 81ju+aewg i7 ,v u2lvf 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 y/pz ;m7-r (kq,9t7* h(ala nfmsr skja speed of 20 m/s. The centripetal force provided by friction is (amr nls;pam(7 fsq r9h7j-k*z/,kyt$1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a speed of 14n 0d5x.:71*i2kaccv;ui;w r,t)dqcdung o mh m/s. What must be the minimum coefficient of frictio;dwv1q, 7c0mdc niak2.u:odnxu*g tir)h; c 5n between the tires and the road for the car to make the turn?

  A car is moving with a consttt(x7 a exo1)pant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the tote7(xa )xp1 car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 1w)a-ko .0)eensie3tbf r yvwp75 9a8g 00-m r8wi r)a 759setbg3p.ke o)vya 0- nfewadius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankb-ei9+i m(ulvdx *iv9 ed 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 an q+ *x549baup*ixryh oangle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m isrpg, deh:t** y4 g *r.tkpg5tw banked 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 revolving uniformly in acd0-oa zu+n qi 1(fz erb9)ch9 horizontal circle of e 1-orc9hibz (ac0dufq )z+n9 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 unip u 4z 4m,zau f3f-pym;5lr /bro:fw(vform rate to a speed of 45 m/s in 15 s, moving on a circular trap: rzfbvlymfm 3or z4ua4 ,/p;w -u5(fck 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 consig t5w3u y5 ;0gugpofz0aop. 1ssts 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 Eartbbdp1 :0mku46k*xlloh, due to the Moon?umo4 k:b1l6x kl*dp 0b 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 masses is F. If the z7d9uea(gg 5t masses are moved to half of their initial distance, what ia5gtdu9gze(7 s the gravitational attractive force?

  For a spacecraft going fpy)7 j+zesw i(f4oar -rom the Earth toward the Sun, at what distance from the Earth will the gravitational fop7(a-fw4seryzo ij + )rces 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 d5 lgk2/vw8 ) k5ql20/,eet z fhwwmpbis $7.4 \times 10^{22} \; kg$ 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 vk*3sxxk uw2 ent: *)im d6/rya distance above the Earth equal to the radius xsdy*:k2/e)t v xwku* rm6i3n of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will:;om 2pu,iq +mbdon4l the accu+4n: ; ,pmoomidqb 2leleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a wico.* 8xbnn7n:q8k sdistance above its surface equal to 3 times the radius of Mars. The acceleration of gravity oxnb7nsq88k ocn *:i w.f the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some pla:vwlv ,:zaehk3bw : n,s- hao4net's center, the acceleration of gravity ,w4ha v:ze3b,lo:h:k -wasvn 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 Ear u:a6wd 6*lcxrb ;a5luth has radius r. If the object is raised tocb5uw66 *;adllau: r x a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weigvqb r/7 jkse1prnh 953ht of a 100-kg person change when he goes from sea level to an altitude of 5000 m? ( v3q1knr pesbrhj 759/The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is a19w xcv w8ct31lapd1 xs (u3wbt a point 3r above the Earth's surface. What is the satellite's weigh18b wdctulaww( cxp319xsv 31t?

  A spherically symmetr8r;agub n ,8foihccw(cj)o1e/ o ,er :ic planet has four times the Earth's mass and twice its radius. If a jar of peanut butter wei,/ n,(eoohr ) o wr:cg8j1iefb8;ua ccghs 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, and Sun e2 ur / tra rar27,-popi3vpg+all lie on the same line, with the+rgripu72p3 v-a /,o2atrerp Earth between 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 thmpzcf ; rkovr*5ju18rq**+pzuii9o 1 e 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 3 sy(:iem g:wl6i,ifees- dw2 Earth (i.e., it just skims the surface of the Earth). Whl-ydeg :f2,(smwi3eei is: 6wat is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low c( m 4tk.-w9y82fh(tmw4: qdmsod ))rbldbpk zircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the E2 :httd (m-)oz4yswmm kl .) k(fbp w89qddb4rarth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the ukvg 3undm18,f bzl- 01-skchsurface of the Earth. It is on uzd-1 kk3lhm8 -vsguc ,b10fbserved to 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 6 ji) 2cqfvm+zdiameter 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 w j ;z,w;5+3ydn 02q*oym; szvbovoiyuith 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 circulartnegh3 (g (wn0 orbits. Moon A has orbital radius r, and moon B has orbital radiue(wt(n n3g0 ghs 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter iaj01bhd/ zm gm1 j(tx.s $7.78 \times 10^{11} \; m$ 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 orusb 2vp5 zqca (.a92h1v fc 003ylpfxgbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from tvps2vgpf 5h0aq fb1 2 0(yzxula.39cche Earth to the Sun is $1.5 \times 10^{11} \; m$.)