Is it possible for an object moving with a constant speed to accelerate0 wlzbqv7ib4yt7 rk;+ ? Explai;ib + b7wkty07ql4 zvrn.

  Consider a particle moving with constant speed such that2d xel*rty +ax:p1pt/;. ps iq its acceleration of constant magnit 2 *r+1stpatqx;:yppil/ d.exude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dir*py:fjo+ncw 2at5ea2symyel/3ls w-1yl7 y / ection of the object's velocity and accele*2o ym f/ 5se lywyjlwn7elst3-ca:/pa1y2 +yration vectors.

  When an object experiences uniform circular moi.md zbe ik**92uttz3 m ku5b2tion, the direction of the accelerat.z2 *k5b2zkt3itumu9* bem idion is

  Consider a particle moving wity+.hyh h.c1 kgh constant speed such that its acceleration of constant magnitude is always peyhch+.y 1.hkgrpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in cb;4v 3i jn4jxyxd8i1 a circular path ej8 biv1 xx43dijn y;c4xperience?

  What force is needed to kykb nwk-6 mtmrnks. t,*n84/,y3h jomake an object move in a circle?

  When an object experiences uniform circular motion, the direction of dafy/ f.(-m tlgh5: rfthe net forcearf(dy f.-gl t:m f/h5 is

  A roller coaster car is on a track that forms a circular 7 koqdnvr n.7 5s2pmo:loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal accem 7 rqn2np5okod:s7.vleration at this point?

  A roller coaster car (mass dsurpj v3i( qj v0 qrru i,cj+;20as32= M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just mainta qi;j22 idj30ps r0+,sr aqcru(uj vv3in 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 t 9 js jsj*bmlw+y+p w,q36avu)hen follows a semi-circular arc until it is going straight up. Just as the plane is,3b6 9upws w+*yqjjv sj)+mla 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 of radiu4 ddz+y4 fwfq*s $r$ 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 gopaj- 2oekj+y*es 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 paok-j+ *2yejtime, compared to the first time?

  A car goes around a cu m zkd1xt.a s-m*s39itrve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What isdm i stx39s1m.tk az*- 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 speed v. If the roargz u )1h:s1dzs8vh g(35ppl ;q ajs6bd is frictionless due tops a 5 (zs )83b1;lg 1zsqpdhj6uvr:hg 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 ongx-yh5)1q ii:lq;ll j a bobsled 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 the larger radius xyiljh:gl)i- qql5 ;1curve?

  The banking angle in a turn on the Or:6 *y y(tk lhnaxii :b:;kb)elympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "cl ke*::i6y yt(kbnrl axb;):ihimb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an objeciw3 9k5m* ttqyt moving around a circular path to have both centripet wmt k59iyt*3qal and tangential acceleration?

  The gravitational force betwee32csu4 ihkm9 mn two objects is proportional to

  The gravitational force between two objects is inversely5 re)la+c9h;e qw qet+ proportional to

  Two objects attract each other gravitationally m6b -yx: jy j/z7,caxn on3;0emsv1.o yb.zwj. If the distance between their centers i:..6ow0- mn,jb1 y; mx/zbjcy zo3yxase jvn 7s cut in half, the gravitational force

  Two objects, with masseynu ls7 9x*uw,jn 9/ e;p)tcfhh/cf*hs $m_{1}$ 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 mas4p7+ d gqjf0baa s)s6bses $m_{1}$ 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 unive 2ypv45se+/od 1w 6s.nu dk8vpb9bcjvrsal gravitation.

  Compared to its mass on nx.h0 om(j+ ntthe Earth, the mass of an object on the Moon is

  The acceleration of glvpv n .,k: bpi)1wn/mravity on the Moon is one-sixth what it is on Earth. An object of map,bv/.m ni)1k:nlpvw ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from t ukraak* g()jklmoiw(m z-j:4u7e9 u4 he Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At;t0*ql/v n.zw r5k ocs what point is it beyond the pull of Earth's gravity*vtr .zn50q;/ lsckwo ?

  Suppose a satellite were orbiting the Earth just above the surface.hh v 1z)z*7iz(;a ;b.quwj f0 7fyezok What is its centripetal acceleration?;fajyu*h(z q )h;zv 7zebkfw7zi.1 0o

  A hypothetical planet has a mass of half that of the Earth and a radius ofhvzllq ,xq+vx2* 9bt7 twice that of l+, x*b7tqh qzx2v 9vlthe 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 gravityd-f*b28m) *gz urunwv on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of t8 *)f*uvr wbzu2mg-nd he Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface grfgdpx z,h0;u5 ikxh+ut . m c9:xf18laavity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of fa0; hic:1mh9,g 5.f+zxu8 x xtdklp uplanet B?

  Two planets have the same surface gravity, but planet B has twice the mass2omj1j5m wq/t of planet A. If planet A has radit1 ojmm/ j5q2wus r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheyfodvky6i 5pk)0jq 8. rical planet (mass M). Which expression gives this satellite'fd8i 5)6 yoqykpk.vj 0s orbital velocity?

  Satellite A has twice the;t5 sd/jv orh( mass of satellite B, and rotates in the same orbit. Compare the two satellite's spej rd/5tsh(vo;eds.

  A person is standing on a scale in an elevator accelerating downward. Compare wzg7)+ l0ltv kd*tz ;ythe reading on the scale toz k)t0 ;wvy d7t*lglz+ the person's true weight.

  Who was the first person to realize thato 7pydq,4i 7pc the planets move in elliptical paths around theqpcdy7p 7,4 oi Sun?

  The speed of Halley's Comet, while tz4ry q3pp.g2 uraveling in its elliptical orbit around the gr yp2uq43zp.Sun,

  Let the average orbital rad6emjxr x +s5njz1k2nk -v b8q4:4mhxgius of a planet be R. Let the orbital period be T. What quantityk6 jkqje:xnm2-8 x1 n 5zbg hv4+xrsm4 is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in thebhv8k(ebx6,o*tp e :v galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 k*e(pboh:tv,e xvb86times 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 Eartzj5w uhf uv86/h to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average dis5w 8f/ hj6vuuztance from the Sun?

State Kepler's laws. , v,f7,ehulxa

  List the four fundamental forces in natd 88 pew-8 /7n1kpgm5ssm; y:urihvlgure.

  An object moves with a constant speed r*bsk t96ax*n of 30 m/s on a circular track of radius 150 m. What t*ka*x6s9brnis the acceleration of the object?

  The maximum speed around0l a6 b50dfs-d*v tlo(fybaa- a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all otb *adyb(aot0-0ad v sff56ll-her factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle wz, 1:oczff1it :i* t2 dq2as5kujf2q theel of diameter 70 cm when the *2f2: akt 1d zf5fs2qcuq: itj1t,izobike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s (sujsp/w 4l:w is located 0.200 m from the axis. What is the centripetal acceleration?uw/ ( 4sjswp:l

  How many revolutions per minute must a circular, rotating space sta;(-ro2v;etj k. j*hvjij8kostion of radius 1000 m rotate to produce an artificitvk-oe2v ;jjr(.s;ij * 8jkohal gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiud2 s hul7eg-)sq 5(rgzs turn at 96.5 km/h. Whar- ug5q(lh)esgd s27 zt is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The s53s f cvqff5c0gpqlni5o 8(/nystem is whirled in a horizontal civ/n5p0 cqigf s5o53 nlf8cq( frcular path. If 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 strong string and whirled i9o:h(by 3k audgp;v ,rx7a)d wn a vertical circle of radius r. At the exact top of the path the tensiokba;o(a 39:yhwd 7dg u)x,r pvn 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 isg(z ov)z* xyz5hi 53.vnbep86cw y *vertical circle of radius r. At the exact bottom of the patv * z()5 e 5g.zpyhbics3 *zixyv8wo6nh the tension in the string is 3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experienc 99vft kp* g.ats7u.kyes an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flt 9. yugp7k.*fa sk9vtying?

  A pilot makes an outside vertical loop (in which the cent gvh4 j8 qhlge-n(7 g,cw.few6er of the loop is beneath him) of radius 3200 m. At the top of his loop he is vhjhl(g.-gg 6q4w , cewefn 78pushing down on 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 his weight yok0 o+d,cpm13 pc.ub. What is the minimum radius of curvature that a jet pl od.0o3pmpc ku+ y,c1bane'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 horiwle0 )*t bqd*+/ynjdra5 cq: izontal curve with 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 between the car's tires and each r*0nqar)/y+de j clt *:iwq5b doad surface.)

  A car is negotiating a flat curvenyr 3nhs9; 5ok of radius 50 m with a speed of 20 m/s. The centripetal force pr o5;k nryh93snovided 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. s-ubx9 ghtqnd3 3;1 i z0ctgd.What must be the md .bh3;uq1gn09tct x gz-s3diinimum coefficient 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 coe8dy9ybr;m9 dafficient of friction between the tires and the road is 0.4bdym r9a 8y;9d0. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is requirzc -byhby88(js)x co px7.yhn jv60z/ed for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (0pc h8zjbb- hxo xj ynv/).7c s6zy8(yIgnore friction.)

  A horizontal curve on a kji p +st ;uf ux25g((vdmq8.nbobsled 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, banpthm0bn2 meg*.cd 8f)ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked:m9 e)dhlk4bj 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 striz.ltc(nr ea*b +/ch. r i18m8egvmvs2 ng is revolving uniformly in a horizontal circle of radiuscl mvt8bh vsmr. iea2c/ez+rn *(.81g 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 pittm jz9 8b7d;oh6 wv nn1q9bs0p 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 blanks)sd9pv t1nj8b7h6 0z nq9omwb;
(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 consisazrdk45xdo(upw i ,n70. ec-nts 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 Eart(h m:w u4)e2 sqzgv/ z2ic;zyrcj( xh;h, due to the Moon? 2(hzr:) i xcz vs(;2;j/g4cq wzymehuThe 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 tha vtckc0; h62u by05ww( lrshz. ,x2c /e,igose masses are moved to half of their initial distance, what is the gravitational attractiyhc6ck(5utcvox,sihrs02/2 z w wa;bl g,e0 . ve force?

  For a spacecraft going from the Ee:ql4gcv 6 q08 i,kijvb1ip3karth toward the Sun, at what distance from the Earth will the gravitational forc3,b 80: qkq pgviei jck1ilv64es 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 Moonid*bvi ed* p0:c h)lqtq763 af is $7.4 \times 10^{22} \; kg$ 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 abo6ba)u* :rof1(nt+cm zk hf1o eve the Earth equal to the radius of the Earth. What is her acceleration due tr)aom *ck1+(1bznoe6ff: u h to gravity?

  The radius of the Earth is R. At whatb360s)f+ cedl2tk diy distance above the Earth's surface will the acceleration of gravi36i0 ftse2+ dclykd)bty be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance awdgqbz z3+ mz2uz o:5pp ,v4z2bove its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, 43zw:+z,u2 dm2bpp5g zzvozq is

  At a distance of 14000 km from some planet's center, the accelerate70gzpd y7*uhion of gravity 7 y*egup0d zh7is $32 \; m/s^2$. 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 v p..+wtwqwd4jay t0* 8i,wuxEarth. The Earth has radius r. If the object is raised to a height of 3r above the Earth'sjapwtv .t4w,iqx.d8*w +0uw y surface, what is its weight?

  By how many newtons does the weight of a 100 o74lwova(j1 :yc9cqjf5 ejr;-kg person change when he goes from sea level to an altitude of 54qvjo5: j1wlja;oe(yfr79 cc 000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satekwk51;iu xuc :wbpa(s2g te.5llite of mass 100 kg is at a point 3r above the Earth's surface. We x.tak(:pwb ik wg;u2u5s51chat is the satellite's weight?

  A spherically symmetri1bfcl/rik vzt; , +*oyb*xrs1c planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how,/+ bc fizrr 1 byosv*t*;x1lk much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, cral ue9k/8-g4u;cp k6s9i2 0eousa kand Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass ogu0ee/rupka8 -cl4u 62 i 99a k;ckssof $7.36 \times 10^{22} \; kg$; 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 tyq9 bfhzi,.gf0u0ff)7f yp4qw uz , *pdj-gl4ransported 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 just skio23e x,njw+e7 qc ; qkyy6z+vegl5ji,ms the surface of the Earth). What is the speed of 7+wxy ye ekj n3 6jivoq, ;q,c5ge2zl+the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a lou9 lzmjrim((p dvj 3 0r;)vo9jse,d m;w circular orbit about the Earth (i.e., it just skims the surface of the Eap(rmm9 v0szv3 9 j(e;;od mdr,ij)jlurth). 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 circular orbep z/ox xl(8se hw812kit 230 km above the surface of the Earth. It is observed to have xhpz e o(w1882ekxsl/ 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 diamet43) ugfsdb 8x 6mmxg*ier of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupite t2 ,cr;runt(dr 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 planet in nearly circular orbits. Moon A has orbital r24owqv4; c;nd icsl 9fadius r, and moon B has orbital radius 4r. Moonn2c 4;cfw4dl 9sviqo; A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter iszodk (nj /u8(z+le: ym $7.78 \times 10^{11} \; m$ 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 1 p zlyh4505vhwi8gkf to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The dl kw5h g45v0hpf y81izistance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)