Is it possible for an object moving with a co * /ah)2vbcy)nzogj f,nstant speed to accelerate? Explain,a)2ghy vc/*oz)jnf b .

  Consider a particle moving with constant speed suct.49duzf cd l-h that its acceleration of constant magnitude is always perpendu -.9dt4cl dfzicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the di+;myu8 c hyyazys/ /sfyidepc(/360 frection of the object's velocity and acceleration vectors/y dc 6iey;/fmcuh8 f30yps+( sy/ya z.

  When an object experiences uniform circular motion,otxp88x )s -zheow 2ovy34tb ; the direction of the accele;ox4p tso8 8x t3eb2zwyohv)-ration is

  Consider a particle moving witk+ba9u rwjmh y. tj50kb0g 0p:h constant speed such that its acceleration of constant magnitu :u0prkat0w 0k ybbh.j5+j9 gmde is always perpendicular to its velocity.

  What type of acceleration does be6**tjkzc ; iedjab xll8k/. ;dn*y .an object moving with constant speed in a circular pa bal xj /.e8zbtlc;e;y.k*d6n**jidk th experience?

  What force is needed to make an object move in a cig/ d;ot;z0n;zp sl* vvrcle?

  When an object experiencesf3db*dtu0:m: mkq)n7i ctm)vxj -au - uniform circular motion, the direction of the net force i 3nqtf):bj7a d m--vm:ktmx)*d ic u0us

  A roller coaster car is on a track that forms a circular loop in the vertical pl cv4/ezuju0+c ane. If the car is to just maintain contact with track at the top of the loop, whatc4ju+eu c /z0v is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that fq kv41gwx -5hyorms a circular loop (radius xgk-v14w 5hqy= 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 minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circ :qyq ,b* bgn)mt1e0waular arc until it is goimqbawb t1,n):0e *qy gng straight up. 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 curve dich4 t8 l:6apof 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 speedi;+ hr+whyn i1:hh m1 (qpy-co9 vcu.k v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car a ih ;+(rm1+ cok1wuy9:pyhhv-qch in.s it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of ra+0;s nbveal*pm f/v tec+z:9jdius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal fo va0b/l :sn+zve pj+9efmt*;c rce on the car as it goes around the second curve, compared to the first?

  A car of mass m goes ap kdtl+ 5, -f1qwury(kh; )dxeround a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of thk+ e ux ;rtfwld)dkhq,p5(y1-e 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, but one0 4nw2 r kt(b/9:rhvpm(sxbqj has twice the radius of the other. The safe speed (no friction needed to stay on the rup 0bj/ rxwk(2rq:(s9nmth vb4n) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on thj ;abnas ksrxl+23g6wd*6,w oe 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 los6 3 owd*sblak2rgj;w+ nx,a 6wer coming out of the turn. Why do they do this?

  Is it possible for an object moving arous q j7bhzu ar.;/,5dv6wfz*lita(uc7nd a circular path to have both centripetal and tangential acceleration?shafib rq7(zud*5/t6; w ,uj.c zav7l

  The gravitational force between two objects is prop c*;uyetvw ,u*9t +-opgjyrk1ortional to

  The gravitational force between two objects il9( j2fporyw-l 9 2 6lhx.khvqs inversely proportional to

  Two objects attract each other gravitational63rv .hioo/j kly. If the distance between their centers is cut in half, the gravitational forceroiv 6k.h/ o3j

  Two objects, with masl,wo;kzmg+guhy qg p n+ *xr2-*: lez:ses $m_{1}$ 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 ma1( kvm*ak(-c3gwekf jsses $m_{1}$ 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 universal gravitation .;rxdz u*cr ookfh ;k;5qem22.

  Compared to its mass on the Earth, the mass of an objeclu yl7)u: t3xft on the Moon is

  The acceleration of grav3 xdfl:l j:gn4ity on the Moon is one-sixth what it is on Earth. An object ofdj f3llx :4n:g mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's9liz*sucs 1 0.n .7j/xjduryf surface, the rocket's weight

  A spaceship is traveling to the Moon. At (wf.r6 ggp-kp what point is it beyond the pull of Eart (gppgr6f w.k-h's gravity?

  Suppose a satellite were orbiting the Earth just above txb q0: 7pbqh6whe surface. What is its bbqwqx:06p 7h centripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twig(bobgsn b t3 1wqxy9ux4.: a6ce that of the Earth. What is th9gny:u3bsq ax4( t61b bog.wxe 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;e wx:h z4d:tu Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of :h xte:z wdu4;the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the samedx+ .90) 3f/kbhek orbpso 2a3umwe)e surface gravity, but planet B has twice the radius of planet A.kw/ .)3 s)2k0h+b eemo9er dpxbof3au If planet A has mass m, what is the mass of planet B?

  Two planets have the s2o p zc0;)yd231dprs)yealm g ame surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet B2e0m1z2cdl 3yrp) g oad;yps)?

  Consider a small satellite moo)pjcw fq5/d(qy ww5 z*cpy:/ ving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbita /dc*(/5f z:5 qpwjywpyqwo )cl velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. C8ogge).u gc 6vw,cp qjh*bc+. ompare the twc+ g8egcqhwjp *.)b og.cvu,6 o satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Comparepm 8xfj-0/k:j *olz4k ) klawp the reading on the scale to the azlm: *l /)jk0p pfx-8ok4kwjperson's true weight.

  Who was the first person to realize that the planets moog a2dbh w63k;ve in elliptical paths around theo6ag2;hb wdk3 Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around 8.4qhvp:f +b(k orhd othe Sunbohp+ovf.: hd84 q(rk,

  Let the average orbital radius of a planet b+yrm cs (i;3 cj;ejv,se R. Let the orbital period be T. What quantity is constant for aliye+ sjs;,jc m3;(cr vl planets orbiting the Sun?

  A planet is discovered to orbit around a star in th7x1pm wdboc72d vif01/j+r tde galaxy Andromeda, with the same orbidvc1bfd d7j2ri1p7+ox0 mt w/ tal 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 to the Earth's orbital period?

  The average distance from the Earth to the Sundikn2m ,v t3(x is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third otv2nix(kd3m ,f a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.0cukw0c h,6p /ix3yygw)1 iui

  List the four fundamental +(-*/vv2t sd.ehudl qvza0d jforces in nature.

  An object moves with a constant speed o)t x: n :9rrzhqb8:ygc aszi24fz:t ;df 30 m/s on a circular track of radius 150 m. What is h ;:q:r yxig8 bzdazf)cr42zs9tt:n:the acceleration of the object?

  The maximum speed around a lnt 0-i32jergr evel curve is 30.0 km/h. What is the maximum speed around a curvern3 egtji-2 r0 with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal 40.eyt1 f cqo,id3bvhacceleration of a point on the perimeter of a bicycle wheel of dbc.d3e 1iho,0fvytq 4iameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating an9 l920 kq7 iiue*vhrzt 5.00 rev/s is located 0.200 m from the axis. Whal v i*2i99ekh qun7z0rt is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space stati7 mazszlwoxc/p)qh i*4vg 9 3mjcc8;7on of radius 100c93o8wgs )/amh4mpxc j7iz; czl*q7v0 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aroun;pzfsp.).ylwnx u 0 h7d a 13.7 m radius turn at 96.5 km/h. What is the ce7 nwl0p x;uh)zy ps.f.ntripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end oi60uvd slh -j*1ya4nl f a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstain 410v y hdju-a6l*slnd 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 strong string and whirled in a vertical cmvm3k(e mwlt)0d.gl n+ o9f(sbpm))y . qr1yvircle of radius 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 t )93( w)me(v0pt.mlyov qsdkb.g)l1 fm+ym rnhis point is given by

  A stone, of mass m, is attached to a strong string and xk40g kha +wbfc/cza,h (kb16whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the strah/01b6 cawxcbzk h(g fk4,+king 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 vpo:4 .prr*p pan acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop iv.p4r*por p:pn which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is beneam /lk e2whu7a;th him) of radius 3200 m. At the top of his loop he is pushing down on his seat with k ulw/;h7m2e aonly one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weigmdf3wjj* ik jee 2(1ab2s7wg; r4p4an ht. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of(a ;j7e a e2drgbjs1m*4jwp2nk3w i4f 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with.ltlt;x - laf, the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction betwexll a,tt .lf-;en the car's tires and each road surface.)

  A car is negotiating a flat curve mp 0,+b-u9lo1txsy +3y afxbnof radius 50 m with a speed of 20 m/s. The centripetal force provided by sa3 y,mbf+p-lux +btn y1o09xfriction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of ri7hn8 ja -k2wgadius 50 m at a speed of 14 m/s. What must be the minimum coefficien2ng7wk8 h-aj it of friction 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 curve. The coefficient o(j r2u o/v3r( ;wn.stvf5 dblxf friction between the tires and the road is 0.405j;3vwu 2(v.snorfb rx l( d/t. 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 Olympic b 6z8.ix, *a7ubn3s zckkyac, eobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictionykk6bczca, * a7.u3zx,s 8ie n.)

  A horizontal curve opcn83 5s/c*:w/e +q4vswxg kntq ljn+n a 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 )0degan s gq)bs5p..w at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 ))g.ldra+rr(z5 q ; x2wypgxhm is 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 ri.v.df *6qvua horizontal circle of radius 0.5vv u6q.*irdf.00
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 i;k tay )s(cea-n the pit 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 numerical value in the blan-ast; )ekyac (ks)
(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 mury,y.c60g sb)pqpr-4a2 urr ass $1.67 \times 10^{-27} \; kg$ 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 f5kvbl ila8 p:+orce on a 70-kg person standing on the Earth, due to the Moovpba i lk85:+ln? 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 massesr 2zudmc9esjoh 13u(2 are moved to half of their initial dista s ej1z(m39ud2choru2nce, what is the gravitational attractive force?

  For a spacecraft going from the Ecva u3o*4*bfmq/ ir 5darth toward the Sun, at what distance from the Earth will the gravitational forc fbcv5qrmai3u4 */* does 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 pp,zw6 dg.wg61 b lmw0is $7.4 \times 10^{22} \; kg$ 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 distancmar.hwv.df f1fdt;3 m7sj5 .z e above the Earth equal to the radius of the Earth. Wh m s3hdfzrtdf.vw1;ma7j.f5.at is her acceleration due to gravity?

  The radius of the Earth is R. At what disogrmbq y3x9sihamr ie)63e2f0t* 4a,tance above the Earth's surface will the acceytqam6i* sb4er 9o3are 3 gm2hi)f0,xleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a disk vn6vtv14cn -tance above its surface equal to 3 times the radius of Mars. The accntc64kvvv- n1 eleration 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 pex/ 3w34 nn3onmwm)4j yby/wy lanet's center, the acceleration of gravitynm3/ /3 b3j4w e4nmoywwyyx )n 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 r9;is ra.v*yqr. If the object is raised to a height of 3r above the Earth' ;aqs*riyv.9r s surface, what is its weight?

  By how many newtons does the weight pi3n*5pt y ; -h8mvy7skq b3fhof a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of pikp3-h 8m 7s;vyt qh3*fnyb5 the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satell0b8+kchepif 2)j6/ u, z nik(unne6kfite of mass 100 kg is at a point 3r above the Earth's surface. What is the sat/(cz ,6i+kn)ij hk be6 82p0nkefuu fnellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twic g:/oxt,dcmd 2e its radius. If a jar of peanut butter wetod,xm c:2d /gighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Mooybl l6jj;yw-x-pg +s/ n, Earth, and Sun all lie on the same line, with the Earth between thb+s- ly-gpjw6xl ;/ yje 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 /,yla nq+my z3hft43k 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 circul8yux8 s*3)ijo bdy g4/ tu4lgc3xbf-war 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 f-34owxggl4 /b 38dysy8ucxjt bi )u*the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skimhdyazw30n ;qsd,n 3h8 axl6t(s the surface of the Earth). How long does it takhlt;3nhzw8qdyasxn3 , 6(d0ae to make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbi )8sv;c. 2 wsm8f2qtj h.w bppaxfbb84t 230 km above the surface 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 Earth i2fb8st xq 8wvp)bpa8b ;.jfmh 4w. 2scs $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, hc75 hzkp pcx94u0n ,rhas 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 Jupiterd5s*7 xorlrr- ug-hp2 oyz *7c orbits the planet 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 plan,j* d)z d7iqmnet in nearly circular orbits. Moon A has orbital radius r, and moon B )i7 qjdz*d,nm has orbital 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 is 2l)diqnbwbw/ zp b.l5 ao 2d-9$7.78 \times 10^{11} \; m$ 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 Su ;i yfd3j(nkfot0s02)xsfw6l n once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to tyx2 3kdff)f60i(0t;sloj wsnhe Sun is $1.5 \times 10^{11} \; m$.)