Is it possible for an object moving with a constant speed /n/pv y 9nvd(sto accelerate? Explain(v ys9/d/pvnn .

  Consider a particle moving with constant speed supvm ogye:2.k,ch that its acceleration of constant magnitude is o2 pyk:, emgv.always perpendicular to its velocity.

  An object moves in a circular path* dq rcw6m5:nveg)8in at a constant speed. Compare the direction of mn* d)qwrc8v56i:ge n the object's velocity and acceleration vectors.

  When an object experienrciy.9y sk b59ces uniform circular motion, the direction of the acceleratc 9kyirs9 5by.ion is

  Consider a particle moving with constant speed such that its acc9x4f j/ybqtj.3wz 6v* rezl )neleration of cons.r3txf9l qn /w e4*y 6jz)vjzbtant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed inl .j )7-huscfv,1zfnu a circula.1 lz,fnhj-vuu7cs f )r path experience?

  What force is needed to make an object move in i1+r s, pxvk:wa circle?

  When an object experiences uniform circular motion, the d( ,j etywsj,n0fqx1(hivfv ( q /j33xdirection of the net force q((0qfx,d ei, vn/(jy3j13hws fxjv tis

  A roller coaster car is on 46y 6pspwif*jr4h6ny s: g;eta track that forms a circular 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 acceleration at teywhfr6s ;4pypg6j *i4 :tns6his point?

  A roller coaster car (mass = M) is onypx y74qz91ld 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, whazq94 7y yxpl1dt is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc untwu56 0f 2xzshail it is going straight up. Just as the plane is at its lowest u05hazfw62xspoint, 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 radiur5ihju osx *(3rk-v60bx b-gss $r$ 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 constahw6.q4oang yll14:q cnt speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes arno lwy:4l qc46a1qg.hound the curve for the second time, compared to the first time?

  A car goes around a cur erj ze ;:roe52k8h/ibve of radius 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 aro:ee8/j orkr5 ;h2 iebzund the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If 8n (vqj-a o1rzthe road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal forv j8zqo-a(r n1ce on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at thec *bsv lpx3m+ i*d:3zz 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 curve* d i* +s:b3cxplzzmv3?

  The banking angle in a turn on the Olzsmz xq+n i;93ympic 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 lower coming out of the tu+xsz3z ;9 imqnrn. Why do they do this?

  Is it possible for an object moving around a circula5p)pe ,vk+m (96wkgt -p0ctn y:tm wqlr path to have both centripetal and tmpl -:) ypkm9pew, 6q+wgtntv0k 5(ctangential acceleration?

  The gravitational force between tw-g d35sr j)rtmn/+garo objects is proportional to

  The gravitational force between two objects is inversely prbsl/qo k x9 c2-:zzwk;oportional to

  Two objects attract each othe 0b) sej/+eyfrr gravitationally. If the distance between their centerse0/)fr+yjeb s is cut in half, the gravitational force

  Two objects, with masses(r.wo )ykf n,l $m_{1}$ 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 masse-ky// yxantzmo q3 6m-s $m_{1}$ 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 universaprbpdap,:3z3 v.1dz o l gravitation.

  Compared to its mass on t7i g;gdhk7 bs3he Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Ms df, xfnb8w:1oon is one-sixth what it is on Earth. An objef1:xf,dws 8nbct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the u7jix v0oia **jfv01p vu-id-Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyon)ng ,ffl8k+ p k+/rovn1hoc y;d the pull of Earth's gravito+/k,h)1;k flco8 n+fv nygrpy?

  Suppose a satellite were orbiting the Earth jba c;njc-dx69ust above the surface. What is its centripetal acceleration?9ab-;n jccd x6

  A hypothetical planet has a mass of half that of the Earth t1f76. axiv +yzx.it eand a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at thex7yx eit+.ft a .vz6i1 Earth?

  The acceleration of gravity on the Moon is one-sixth whafz1-g.*kys vm gi8w(yt it is on Earth. The radius of the Moon is on - 1v.s(f8gkm*yzygwi e-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravitqh:+, mgvd :pibjl/ )ty, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass d+p,t:)g:lv qjhim/ b of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of plj;hrsdnc g() +j w3k5n izz(z*anet A. If planet A hns)zkw*jd (c;z3 +r(hn ji g5zas radius r, what is the radius of planet B?

  Consider a small satellitcgh 8o,e2s7bhfu-k9n6 dw 4hte moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives thi7sewn9 gt, b 6fuhd2kh4-8c ohs satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. ql1gp+-w:*tmus2l avya0 uu7 Compare the two s+2-u:uy71 q*mgpva asut wll0atellite's speeds.

  A person is standing on a scale in an elevator accelerating downwaf;6* uq6ooqew8 fuu /frd. Compare the reading on the scale to theuoqqw f 6ef8;u /f6u*o person's true weight.

  Who was the first person to realize that the planets move in elk :o 6ivf *b7mkmw:)deliptical paths aro*w:) ofe bm:mvkkd i76und the Sun?

  The speed of Halley's Comet, while traveling in its ellipdtnyd iojtuf91c8 b6 2;2acda 8sa:i;tical orbit around the Sun,aoait a8; :cb89ni2y1u;ddtcj26s fd

  Let the average orbital radius of a planet be R. Let the osfcsv1clw:n8+ wx l6 i w 23/w7krksv:rbital period be T. Whk swl 1:8sxv7f 3l+w c nc2wsr:6iv/wkat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy hgdt;j-9)fo7poi j7dmq(j 2 y 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 9hj 2djogim7- p jf7);qt oy(dof that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to tuh. ;xd,l p17lk ql(xhhe Sun is defined as one "astronomical unit" (AU). An asteroid orbits the x1h 7l(l,hu xq p;.kldSun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws..1 rrv2cc 6wmwr,z;r etjr2(s

  List the four fundamental forces in nature.svmn p/45g4-hm3cmh*jkfn c c7+l fg 7

  An object moves with a constant speed of 30 m/s on a circular track of radiu2 ja7wxqrf(0us 150 m. What is the acceleration of the objec ua27qrf x0wj(t?

  The maximum speed around a level curve is krhe/t5 :7t n;vi6zpxg,kgw 6 30.0 km/h. What is the maximum speed around a curve with twice the r g/gn6zp:ev 7xkikrw5 th;, t6adius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeterw0uyvo((- q w..q1jg;k zqp/o dx0ffi of a bicycle wheel of diameter 70 cm when the bike is dkp gz-u(q;/yq oqf(0vow i1. 0x.fjw moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m 8q1kk h1xe df3from the axis. What is the centripeta18x3fk1d eq hkl acceleration?

  How many revolutions per minute mus8y 3.vu/b3 p9r3 ltux qcm4sgr l v3jrpt64(ctt a circular, rotating space station of radius 1000 m rotate to produce an artificial gravit6u.9v4urmpt3y 3v4rscl 8l/ p g 3tqrjx ct(3by of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1j:rm;zhx 1f s13.7 m radius turn at 96.5 km/h. What is the centrip1 f;zjrh1x m:setal force on the motorcycle?

  A 0.50-kg mass is attached to the end ofkq+ ta j80+ydg 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 the string+a8dt y gq0+kj is not to break?

  A stone, of mass m, is attached to a strong string+hdj6p)b bvc*q4 7uyu/q.gpmtbsc88 and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. Th qj.c*pq4/s88 hvdt ) y+ub bcpbm7u6ge stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirle, ;nb ;qldbfe9d in a vertical circle of radius r. At the exact boldqe;bn;b,9f ttom 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 jet plane flying 600 m/s experiences an accelerapj,eue*aolx3 7zs 4fo+9, gjqtion of 4g when pulling out of the dive. What is the radius of e4,+g*p3o x sjlfu7 j ,qz9oeacurvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which th 8f gfg7avn/h;e center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only;g f nf7a/8vhg one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weigyue: d4vv)x8cybs 60e6(qbm cht. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, cabcc:m b4)v ex 8y0yd6 (svuqe6n tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rouncyqi+u9,sm9 dceh 11qktjc4 , ds an 80-m radius horizontal 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 road surfac ,de91c h,9s+ci1uq4qmck yj te.)

  A car is negotiating a flat curve of radius 50 m with a speep38rbi p h8hi3d of 20 m/s. The centripetal force provided by frictiop8b h8pr3 ii3hn is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a fc cg35 6k5ztz;ksxqej2wt0- ilat 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 fc-ejstzq kg; t cw2x0k 635i5zor the car to make the turn?

  A car is moving with a constant speed v around a level curve. Thde)wr7wr1f cih/d mh7;p*/ wme coefficient of friction between the tires and the road is 0.40. What is the minimuwdfrm dhm;7 hi7/1w p/)*rwe cm radius of the curve if the car is to stay on the road?

  What minimum banking anglei (gc;:4 g+ k)(jeatb( k:de+btajpr j is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skiddi()+k:t;c ejgaji+(er tb4 d bg(j:pakng? (Ignore friction.)

  A horizontal curve on au,bhig g *y(cv6+05 xih br,qe 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 1000bqu z f/qsf/u24 d8dx m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m ibdx5 j0 hpx.x3rgf16gtff o*+s 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 a horizontal circi za() 9u(-mnun5 mosvle of radius 0.500 nn )vi(9ou5zsm(-au m
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 unifono/vkm) -cz-)0xq qshpp v/*crm rate to a speedv k)m/-sx)-n*qvccp0qh z po/ of 45 m/s in 15 s, moving on a circular track 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 wzm1p 7 frqp2) gt*.ptof 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 oj+foancpf9a 4p /te kvlskjq j q9at18q 18**7n a 70-kg person standing on the Earth, due to the Moon? The mass ofksj1 *ao* jq8jpct9fntp418+ ae7q9 l/fqakv 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 F2adao/ 8 uv;o5 k:g vuspigr9:. If the masses are moved to half of their initial dk:pg8d 5rvius2/ o;au:9o ag vistance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what asb ov;j n mq 03o +pvmnd./fugte..20(vnd.kdistance from the Earth will the gravitatd kgj;otdmbm.2. n 0n3+0/eqpauo.vn .vv sf(ional 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 isfz4(y1ufr o2 vieao;4 $7.4 \times 10^{22} \; kg$ 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 k m+, 89qhtp 75wdfzmka distance above the Earth equal to them7kpd95h 8fqmtz+wk, 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 surf6ju 1; hqx9 fgi*6imppace will the acceleqpx *gm66hi f;p u19ijration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfa4 w j3ej hjc;t8p0f7vc o6om7fce 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 wov3f 7f870pj jc6toe;4 mchj Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of grav9j9dfme0n)xh qyvh /(ity /9 ydqxn(mh0 j)he v9fis $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the s-c a8 hjpqfmhex6vbp(use:1p o0+g 78 urface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surfacegf8hvse -u 7h om1:( +ecb8p60pp aqjx, what is its weight?

  By how many newtons does the weight of a 100-kg person chqve1l4ly5p;l2qedsmns(sj6w wn , :+ange when he goes from sea level to an altitude of 5000 m? (The mean radis +6m,lyd5qnse 1(wewql4vl;sjnp: 2us of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at aeakk3g-m 7o +vxb6o+t point 3r above the Earth's surface. What is the satellite's weight?-+eo7 t+o km gkvb63ax

  A spherically symmetric planet has four times the Earth's mass5mx2*r (yx uo:fvyr +t and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it we vxr or(:yu*y m2f5xt+igh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same lo. o/qj rv*6k3 )uhwczeej ,j.ine, with the Earth between the Moon and the Sun. The Moon hjrcj3j*k)u ,voq6o z/ . weh.eas 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 Moon.8: +oxwbe a-lov fs mg.c e 4c1y.u,e+isd-;bz
(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 skims thesvymms w-9 *p, surface of the Earth). What is the speed -mmsysw9,p*v of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circula hcuf6zlf1h7cpdw2 d(u90 da,u6w.n sr orbit about the Earth (i.e., it just skims the surl0fuh2nf uduh61 9wzc (6d,wa7s.dpc face of 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 circular orbit 230 km above the surface of the Earth. It ,h9/rvhqg .4;iduy* 7xikgds is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth is q9 d4hhxiu7.r v ;d,iy*g/ksg$6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter,( v5nzr b7k(xuw,5cf z has 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 Jupiter orbits the pjn86jnud oqp 8j/ w1x5lanet 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 circu t (2ttt2y 9gi177nts(baar uplar orbits. Moon A has orbital radius r, and moon B has orbb(s t9tn7uart27 p12(g ia ttyital 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 isyec61; 1zkvx kkh3( - sefw*rj $7.78 \times 10^{11} \; m$ 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. Whatrujfr1 vnz d*;7 5*ert is the average distae1rn;57fzujtrr **v dnce from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)