Is it possible for an object mov l7 p(uowh7cm bdx3bc/etk27+1v7xt ring with a constant speed to accelerate? Explainxv+bkdlb /hemw2p 7otx c(ucr3 7717t.

  Consider a particle moving with constant speed such that 4pi+r/fb8f-go lj y,dits acceleration of constant magnitude is ay4 -/ro8lbgpj f+fdi,lways perpendicular to its velocity.

  An object moves in a circular path at ax ey/fq9ps/2 8zul:4sa+ yyvz constant speed. Compare the direction of the object's velocity and acceleration vxf vss 8l4u2a zpyy/9 :/zyqe+ectors.

  When an object experiences uniform circular motion, the dirlm-at*71 yw,qb2v z a0bq8 zxaection of the accelerat2tw 0y zbzvq, aqa*l 71ma-8xbion is

  Consider a particle moving with cobdb)x3r 0 zjw0nstant speed such that its acceleration of constant magnitude is always perpenj 0r)bwz3db 0xdicular to its velocity.

  What type of acceleration does an object moving with consta -t 0*.:aho3vg joaekdnt speed in a circular path ex .0d:o 3a-ov*gakehjt perience?

  What force is needed to make an object move in a cirao0 3 tpq5ek xqmyg/qv(n;zh+8z;c2pcle?

  When an object experiences unib/wk h6x2eysm +)xh;;y 5 hvvsform circular motion, the direction of the net for)6wyhx+mevy5 kxhb2v sh;;s /ce is

  A roller coaster car is o x-,p cb8,c1zsdu ba4an a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at bz,udbp4 a 1cx,a-sc8 the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (massk7:ia+ xxn s4rm+-ud j = M) is on a track that forms a circular loop (radius = r) nk 7jx-ui 4 +srmdx:a+in the vertical plane. If 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 semi-circular arc until it is go6 bl92)ksm odtw(b, loing straight up. Just as the plane is at its lowe,bo wk2m) (l9o6bl tdsst 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 n oue)ah .exk72 ff6/hof 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.3tiwh4yd rw (y*z*;evf ldy*) 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 time, compared to td )ywlt4dy**z f3*vir (hw;e yhe first time?

  A car goes around a curvec3+ee0oe 1ervy(lzx ;,5 vu ug of radius r at a constant speed v. Then it goes around a curve of radius 2r aoey3rvz uge1;uel 0+( xc,e 5vt speed 2v. 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 with sp(wp- b )owmu+ uc pi gxokdxu4j+-o/+;eed v. If the road is frictionless due to ice, the car can still ne++du)b+jwi uc;u pwx(--/pxo gkom4ogotiate 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 bobs1wx +) t0x0j p pblux+h9oxlf5led 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 smaller radius curve is v. What is the safe speed on tl9j50)1xxb+ to w0xfl+ pphuxhe larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not consu3qdg ew j2j ks4nt oy8-3h)e(tant, but increaseqn3h8jwu jt43e2 k- y sgod()es upward 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 a circular path to have both centri28zdwlg,m(yb g w0d +h8uy7z bpetal and tangentiallz (0y8 wbb +7 udgw2h8ygmz,d acceleration?

  The gravitational for iam9k .g1 akxamx)g/g s8i(t-ce between two objects is proportional to

  The gravitational force betwe)w)metm 0jbja:k.dq:, he ,qven two objects is inversely proportional to

  Two objects attract each other gravi sd hbs*l,i(p;tationally. If the distance between their centers is cut ihsi*dpb ,(l ;sn half, the gravitational force

  Two objects, with massestq.ry0 ,b:i) aqj0 var $m_{1}$ 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 massesym1jerc t lm8) df.):w(;eay v $m_{1}$ 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 universa.bn 0lbl4.eeuxx1u s /l gravitation.

  Compared to its mass on the Earth, the mass of an obf;z5,) n/vzv k ns9iorject on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An ob kp6;o*aa9 8xyg 2bsbyje*kba 6;p2as bogyyx98 ct 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's weight,vvjs em39m3n j (ji2r0dhlvxp(+d0q

  A spaceship is traveling to the Moon. At what point is it beyond the pull ofswm9r uwm*k4 , Earth's m umk*ws4 9r,wgravity?

  Suppose a satellite were orbiting jvvgap0+.cge s/s252ebe1 m xx)sq;x the Earth just above the surface. What is its2m.vvxgs exjs125/+ a sxbg eqp;)ce0 centripetal acceleration?

  A hypothetical planet has a mass of haqabl i(:6(tf q2gm -xglf that of the Earth and a radius of twice that of the Earth. What is the accele g(q qt-b:6f(lmg xa2iration 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 what it is on Earth. The r1fjmw0-2xs z wadius of the Moon is one-fourth that of the Earth. What is the Moon's m w jzwm21fs0x-ass compared to the Earth's?

  Two planets have the same*3 ycre3gje)r*if qj+uazcq n 1 5bi7( surface gravity, but planet B has twice the radius of pl)ecu*qf35 g73 r qci1i+jera zy *(jbnanet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, bunns*tc 8i1. 6ylng owoo.a+- kt planet B has twice the mass of planet A. If planet A has radio okgt1w* c.y86noann- l.i+sus r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius1q.r cq :7cqphek d:7e r) about a sphericalrcq :7d q1.kheq:cp7e planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and r2-1ygbv ym7z rotates in the same orbit. Compare the y-2 1yrmbzgv7 two satellite's speeds.

  A person is standing on a scale in an elevator accelerating f9mlntd z50t+ downward. Compare the reading on the scale90 t+5fmz tnld to the person's true weight.

  Who was the first person to realize that the planets move in elliptical paths aar/figr3 ;( qvg8ctt4 round the Sq/ ggr34 i;(trtcf v8aun?

  The speed of Halley's Comet, while traveling in its elg c ;2+b8iackxzcn1eq,:fe xqy4-kksq i: 18eliptical orbit around the Sy1xce1 8is, q42g-qc qbnee :kk8k:;a ifxcz+ un,

  Let the average orbital radius of a planet be R. Let the orbital pevk1dxy;. jssgu 217 jbriod be T. What quantiyvk1ubs .17jsg;jd2 xty is constant for all planets orbiting the Sun?

  A planet is discovered tc 1swv1 4lj ydgb89la;o orbit around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times s vl1a9cwdg;48y1 bjlthe 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 thw*i qqj0ero1 6e Sun is defined as one "astronomical unit" (AU). An asteroid or6jqr0i q1woe*bits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.w4v r*h vcdu6xw((n 2d

  List the four fundamentkp j9s5j vv(izb5n 4n0al forces in nature.

  An object moves with a consrcbass gg55)7 )m n164lnzdqstant speed of 30 m/s on a circular track of radius 150 m5 7g5m 1sg)az6 c)nslqd4snrb. What is the acceleration of the object?

  The maximum speed around a level curv7 a9laoz3m ;zly(m;u le is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assumez alla7u;l3m 9z(moy; all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the periqyy(n 0*z a y)wc.3zskmeter of a bicycle whs.az3y* y (0z) cwkqnyeel of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.0 wn8zb5 (jek0q0 rev/s is located 0.200 m from the axis. What is thzq5w(0 8k bneje centripetal acceleration?

  How many revolutions per minute must a circulzljxs.w .a4t. ar, rotating space station of radius 1000 m rotate to produce an artificial grav .l.xzw.s4jta ity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes arwev* 2vt 0v-kjound a 13.7 m radius turn at 96.5 km/h. What is the cek0vv-tj 2wv*entripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. znsu+4 wl(dh*pfp4z x.:9dwe The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is dp:zn dw.xweh*+4l 9f ps 4u(zthe maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attachegtqya9p7da mvmdv uj0,k -91yt,6/l qd to a strong string and whirled in a vertical circle of radius r. At the exact toau,9jagmym-q9q vy vt6,/17 kplddt 0p 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 +ufs (qnajr5*attached 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 the stone's weight. The stone's speed at this pointra+q(fns*u j 5 is given by

  A jet plane flying 600 m/s experiences an acceleration of 4scnw:r+x3w fl3rv60y7vfco4ja9(im yd mr;4 g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is+( c;m4v0 4drf ian f3ry9x:6w olrjcs7 y3wvm flying?

  A pilot makes an outside vertical loop (in which the center of the ltvgdbuj*7 9k /0/7ifhchka )loop 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 weigh7a)/j7hcgi*kkd uh/v0b9 ltf t. How fast is he going?

  The maximum force a pilot can stand is abj.dl)ej ;cv 8bout seven times his weight. What is the minimum radius of curljbe.8;d jv)c vature that a jet plane'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 cd/tg(fg+ 6nq 80-m radius horizontal curve with the tires on the verge of slipping.qdgncf6+ (/gt How fast can 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 cenl7mdsbhw :3pv,fm cr * 3q7xu,tripetal force provided by fricti mw7h3, 3l :dbrvmsq7 p*fxuc,on is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat+f:( v/8aayey/ thd7umec aa0 curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the tur/ ac/u0 : 8hey f(v+7adaatmeyn?

  A car is moving with a constant speed v ard fl vbt0:r(jna)4uh b++db /bound 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 car is to h/ad4l+):b bbu(tv f j+rndb0stay on the road?

  What minimum banking angle togq3; 5p f,esior9 :bis required for an Olympic bobsled to negotiate a 100-m rados:q 95b3iro fte;g p,ius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on ava1y;v w:sdg5v/: 6jwa fot :yrwk3i( bobsled 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 an1 r8kbgb; x2 axyddk.18oz(0m iypex1 angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banktke)wfm l0)-q8 fgnh 9ed 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 uniform. zearc p+ fb-:o9mw4ply in a horizontal circle of radius 0.500+4a fec-mpz9opwr b.:
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 uniform rate to um; +( cmk(ohpa speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in num ;mkm((o cpuh+erical 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 con)-k:ee yr edy5sists 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 pe ufh. 8 sd;(/9oxugdmkrson standing on the Earth, due to the Moon? The massd/ u( fukhmsd.o9g 8;x 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 9sdn rwpq81/f two masses is F. If the masses are moved to half of their initials wdrq98n/f1p distance, what is the gravitational attractive force?

  For a spacecraft going froman nu3p*1zs7:m.t5 d)pq8lf r kbin (d the Earth toward the Sun, at what distance from the Ea 1*n(7: dub lnsp8 p5nf3zti.md)kqarrth will 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 cs/l m zol5l1;z,nd ;v$7.4 \times 10^{22} \; kg$ 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" atff fr+h:ki0 uwbp(w)) a distance above the Earth equal to thh) u +i:p)0ffk(fw wrbe radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's sd . uu:e96hsiwurface will the acceleration of gra.:u6hud ew9si vity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its su sm2 m;b(ru66jok94b 9yvfrzw rface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity onby 6 bu so9v9m 4j2z;6wmrr(fk the surface of Mars, is

  At a distance of 14000 km from72j(blz4f0 l ia7 oivp some planet's center, the acceleration of gravity i( p4fi7bai7o2 zlj0 lvs $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surij4nv f8q1 +q6 2s1d3:uhd vuumrjgyxh62 4jsface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, wh 8 1ujg:jnvhd1mv3y62s+q irf d 4hsx6u4uq2jat is its weight?

  By how many newtons does the wei-uidl6 46exbj ght of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean ra-j lud4b6xe i6dius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a pjes -*agz.fljf p 7r a8yjq:66oint 3r above the Earth's sf a- :p6faj87ej *gl6jq zsy.rurface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earh1g 2mz,mg w.b6x:mljth'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 su :wl1mxz.g,mbg m2 6jhrface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same p2n: 9l/pzw)m kaym2am1k.ik line, with the Earth1mapn2) mpk29.k/iyazl m :wk 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 tr,x7*.r5rvaxw ab8s jfg4d(qf1 gkg x -ansported 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 ci;*z1yf+ 6xg jit vwxv1rcular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? vitfy1 j*xg6;vz1w+x (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit at i3 -m,giopha0*5qu;yh )s orbout 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 radi;3m g oqsy0i )h-r5oapitu,h* us of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the suynze p*w*/73t1tn pclrface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Ear1 ype/*wnttnl3c* z p7th is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital53l uv xxtffxyh.ykyi62 *8k; 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 )1,ts kc-ss hzz;j o+;qu kg7u--tdl 4y9mgwmwith 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 radius 9g o-o2nmzre.s : zoh6r, and moon B has orbital radius 4r. Moon A takes 20 days to complet2 zesh9-.norg6 :m ozoe one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is :*; 4fjqz eq-zv7 ogr7c lxw0f$7.78 \times 10^{11} \; m$ 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. W klp(3qgpl8.ar0icmfonh : 1 5hat is the average distance from Jupiter to the Su3ao(cq8mpll1hf.k nig: 5 0 prn? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)