Is it possible for an object moving with a constant spebzy pltl5f r5 q.z0k91ed to accelerate? Explail59 r5 tlbk0 .zz1fyqpn.

  Consider a particle moving with constant speed such that its acceleration of con3zve :zpdtn.5 stant magnitude is always perpendicularen3vtzz d.5: p to its velocity.

  An object moves in a circular path at a constant speed. Compare the dir0 k0zy2a- vkigljp4a cze 8(;nection of the object's velocitypklg kvej(yac i8; n02z0a4 -z and acceleration vectors.

  When an object experiencesgd)0p7.w d tcdn2ft z(5 misq2 uniform circular motion, the direction of the accelerati.d2qdf0pm 2 ()ind7zcttwgs5on is

  Consider a particle movi*7wcz. z3 jj9(jxc osbzl: qy/ng with constant speed such that its acceleration of constant magnitude is always perpendo.sy*z(lcbcz7 z j:9x3jqw/jicular to its velocity.

  What type of acceleration does an obxl)qgyspvg)3).6 q cmject moving with constant speed in a circular path experienceg lcy)s6v).q )xgqm 3p?

  What force is needed to mahumyg6o1 wn+d/3(ul8oxs2-e5xs ss3g dtl8w ke an object move in a circle?

  When an object experiences uniform circular motion lvf h*30dn elad4zpy1vbxurr 2) 8942k+ sktw, the direction of the net force is40v9 2lbl3d1r2 hu+ 8tapr*dxves k)n4 ywkzf

  A roller coaster car is on a track that forms a circular loop in thej9;cok:wc3 cu/t.djh vertical planec:wj uoktd/ jhc39 .c;. 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 this point?

  A roller coaster car (massn98 ap o7+lyzid35w do = M) is on 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, what i5+aodw d3oiyn8lp7 z9s the minimum value for its speed at that point?

  A pilot executes a vertical dive then fc:5sx(gk( ao41 sz)dfr4 dwb lollows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forczwc)g1a( 5dr:l k f b(s4sdx4oe 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 r//,ld 5tziqk oadius $r$ 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 goes arounr -qn gvadz5vmt)a88pel1li4c:1 bq)d the same curve at half of the original speed. What is the centripetal force on the car as 5z qnad11) lqr acieg m)bv4-t8lpv8:it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it t:z3z07yjc7n6ud 7f/xw kwm i goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around thet7m73 xwnd z:zwuiy 6j0/f7 kc second curve, compared to the first?

  A car of mass m goes around a banb+;;zar2lz la8mdfl*y;k( fxked 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 the normal force on thm 8z; a*k;d+alxf( f;lz lrby2e car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at t;d311 w+u w+dhy,hwx h) lvrkyhe same angle, but one has twice the radius of the other. T1hw1;u kwy ldw h ,)vryxd+h+3he 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?

  The banking angle in a turn on the Oy8,uuk :e rkzrih)ry;iv) .7x lympic bobsled track is not constant, but increases upward from the horizontal. Cominzhy;vkr)e .uxii8, 7 rrk u)y:g 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 centr;z(o +y4w zyy. 4smkd wcdxg53ipetal and tangential acceleg+yc zdso 5ww4 d y.4mkz3;(xyration?

  The gravitational forto +.rrx vn8eg4wti+.t+d-rc ce between two objects is proportional to

  The gravitational force between. sj6lpw 9gibuswn7vw 2y(d3 6 two objects is inversely proportional to

  Two objects attract each other gravitati hr1yazuj+i k .+2s:neonally. If the distance between their centers izy.: jh u1 ae+2s+iknrs cut in half, the gravitational force

  Two objects, with massn.wb / v7mmea)es $m_{1}$ 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 mass nvr1ec(cc+q-4i w15zrh(egu)g* wp res $m_{1}$ 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 gravit w3 h7vk*:y6a;juk aggation.

  Compared to its mass on the E i)h) 5(epivboy,g xb:t+jy(9xy e( qgarth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-siv9ovjr7o8jjqm8f: qapar*r : )*dbk 4 xth what it is on Earth. An obvo4p*fr8m:ja)b j8* :aoq r qkdr79jvject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's su/,c(8l:mj v dk thj(scrface, the rocket's weight

  A spaceship is traveling to the Moon. Atmmgtsbt8 +yfq+*ttd 0;al/4by5wb . t what point is it beyond the pull of Earth's gravitft +*mla5+. g btqby 8mtw;/ts4y0tbdy?

  Suppose a satellite were orbsrwp32qpv2 8j iting the Earth just above the surface. What is its centripetal acceler qp r3wjsv228pation?

  A hypothetical planet has a mass of half that of the Earth and a ra1 uw-t .ao7b-mpglf2fiz; m.ci4rn(:z(nmz xdius of twice that of the Earth. What is the acceleration due to gravity on tig7-b ixf ma4 .lz:p(nz o- .t2wc(fmnz;r m1uhe planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of graviss;kxme0;,/54 vjc 2q-n+ybs m kn.o/ ahs poyty on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass c h0;k o 2sem 5nkmvpq-n,y4js;bs +a.sc/xy/oompared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius qc32aejyc re j6wkun 2--v4:yr vi.6 xof planet A. If planet A has mass e2 xv na-cj i:-vq2w6k4c 3uyer6yr.j m, what is the mass of planet B?

  Two planets have the same surface a4o;nxeid c jemn9+v3o-;+u e gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of pla u4o9 vei coexa;n+m3jd;en-+net B?

  Consider a small satellite j j:r*( 3b.wt cf0zx(arnsjf- moving in a circular orbit (radius r) about a spherical planet (m:fzw*0bj x rs jc( af-t(r.3njass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of zylir0 a1l 6g/.:zx 7qflj.cke3u.phsatellite B, and rotates in the same orbit. Compare z 1j:l.piq/fuge ykz l67.lah3c .x0r the two satellite's speeds.

  A person is standing jc6ilr q6-zkb-je7 8mon a scale in an elevator accelerating downward. Compare the reading on the scale to the perm6r8 cjk-l bj qz7ie6-son's true weight.

  Who was the first person to realize that thej 26bh /pdyzr6 planets move in elliptical paths aroun62 pr 6h/ydbjzd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around 9:c goo-.ck lbthe : l-gbko9c.o cSun,

  Let the average orbital radius of a planet be R. Let the orbital pe8 u6 yu9assamw-e/v g-riod be T. What qua9wye-ug /uvs6-8 a asmntity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star i,/ )d5jpr)kv-wpydcfeq k 5+n n the galaxy Andromeda, with the same orbitdn +prpdj5 v k w)k/e-cy)5q,fal 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 Eart/gkxm1olqtcqdyu7e 5w.7/ :w 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 dmwk cu57g wx oqt //:y7e.qdl1istance from the Sun?

State Kepler's laws.dy v. 2faxsaq *8d*a9m

  List the four fundamental forces in natur3r7w .s.u )aemsf ap(oe.

  An object moves with a constant speed of 30 m/s on a cir4ybh2g)nhebd( , y dk;cular track of radius 150 m.dy b;,)dk2b n(hhgye4 What is the acceleration of the object?

  The maximum speed around a level curve i. 3p-nhjr8gvhe s :6cjs 30.0 km/h. What is the maximum speed aroune:n p jr v.jg8h6h3-csd a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a lpct z hn(2r;;point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is mon r2t(hcl;;p zving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is lo/.va8j7p6*e fkey 4mpda br a+cated 0.200 m from the axis. What is the centripetal acceleratioayb8e7 vkrf pm.+p6j/d 4eaa *n?

  How many revolutions per minute must a circular, rotating space station of ;mm9uj4cw a9 tradius 1000 m rotate to produce an artifictc m9a u9mj4w;ial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It g/s pp;;-:vekpbs hk /qoes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motor;vpsqeh // bk-ksp:p; cycle?

  A 0.50-kg mass is atq0een s3pz21 d6hc ;fvtached to the end of 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 1vef phnq0dczes3;26 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 vertica 7v (vq4sg/9a4e(szpc 8r4npkgbh.kynnc1i9 l circle of radius r. At the exact top of the path the tension in the string is 3 times e49n1c cspnrnsbg k(vv zh 7 (gkp48q9iy 4.a/the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attashf 3or(b0nz/ v- -nuhched to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in thbvzs/hn3nfu(- o r 0-he 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 a qn wxah:xego (jp9/ -p55mi,xcceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plix9( j o hw/xx55- npegm,:aqpane is flying?

  A pilot makes an outside vertical loop (in which t(b)o3wvkt 4pqow -pn;he 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 one-half of 3 ;p(bwpw 4ovq-kont) his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weightl :l*ih;m j (t(rnbj054g2voclqi)b k . What is the minimum radius of jk;j*bibtr(0c 5) i2 ohqnmv 4ll(:glcurvature 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 80-m radius horizontal curve with me );xn8vzvom(l0a94 )u v2jgr omeq*bj yu :+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 betw:yeo) 4+0gmj2u ;zql *x(avou )j8 b9vrvnmemeen 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 cenaj)) t,eexp4e6,u vr oysa 4t6tripetal force provided by frict s,eata p,yu6vo)rx4te4 6 )ejion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radifa-1yn4q z 9btcvd r1gy- +yz4us 50 m at a speed of 14 m/s. What must be the minimum coeffi1nzry9-tgcd a f+y-bqzy41 v4 cient 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. Thewh5 t/vf j3 c4lkcf;qi+3pxj 5 coefficient of friction betq j5kfi+pf53 v3l;j/ hwx c4ctween the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required m,uac l w/62ayifr-z/v.n:k e for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skiddi /kar:-. u /cmze 2fliy,v6nawng? (Ignore friction.)

  A horizontal curve on a bo dc-;btxw/o-l bsled 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, b 6ch kp(8vncu9anked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atpv );zwd)1vsn $45^{\circ}$. 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 lh55i6vre0, byy qz 7iof a string is revolving uniformly in a horizontal circle of radius hivy60zle5 57r ,q biy0.500
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 x) qb :6iy60 dbp0(qycsm bva.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 numericv6bp aqdsiy0b y.:( cb q06)xmal 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 p(fo xs(bbftz k4p/u/- roton 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 Earth, due to oald1136j2 vw c ga;wht1 dah62vol1jw3gcwa ;he Moon? 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 mhnt- )1o mu(uxx (pv6kt)wp62m:macoasses are moved to half of thtk6-:wpa) 2xv (t(muuco16)nox m mpheir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Se 49 0ni h(9:x/fxewpczei+ idun, at what distance from the Earth will the gravitational forces due to the Sun andi: /diep 9cex+( fwnh0z9iex4 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 m72hjuuz )k)he* qa;zis $7.4 \times 10^{22} \; kg$ 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-waoaouh45 nwsrm/ 5bipox x5 37zr,9(ar lk" at a distance above the Earth equal to the radius of the Earth. What is her accosz(5wmboor5 h/ix 7,xrn rp 4a39au5eleration due to gravity?

  The radius of the Earth is R. At wzhggtnkb6 0k(r * )6*yl n;iknhat distance above the Earth's surface will thb6tn(k* 0;r in6zlkg nh)*ky ge acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its suxi l9f n;)x4riom * 0l xfi.whp6j4-tjrface 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 Marwx*. xj)m-tfn4li 4 ;l6x jh9ii opf0rs, is

  At a distance of 14000 kf f/* i --ubf1c51unzp c,p5z7mrikf km from some planet's center, the acceleration of gravity is f*i1p7k1kc-z pzn bf-5fr/m u c5u f,i$32 \; m/s^2$. 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 r. If w0o4i) sffjz(the object is raised to a height oz) jwf(si f40of 3r above the Earth's surface, what is its weight?

  By how many newtons does the wg e-p7 .vjjhug.,heyehm7 -4geight of a 100-kg person change when he goes from sea. -mpeyh.e7ggejvu 4hg7h,j - level to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 1di-jr 9k 7pyb4l id8:i00 kg is at a point 3r above the Earth's surface. What is ry-kp:ij4i8ld d9i 7b the satellite's weight?

  A spherically symmetric planet has four times the Earth'ww5rav0o m-1rpt xe /t6r x56os mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how muchrxr0w t16tp-5awmox/65 eor v would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on thv *:us *7xd:eezjpgki69 vs, ze same line, with the Earth between t :* ,z6x:7kv9*gj esidzpv suehe 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 transport*dfm,/w1cfevqz: (qe:h sm ) hed 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 cichtrn f3qps 29dq*i)2r*h io 0rcular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellit0h3p*o2s dihrntq *r 2q9c f)ie? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earr. z-)a0ee*u w8 qq fk(k/m vkupvbg2k/m+k*mth (i.e., it just skims the sue8f.bmvk a0/ +mp ku2kgr/)* evk zkqmq(*wu-rface 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 2b.x3+2 3wg dm zbmkq/z30 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 Ea3 q xz3 gbm./kzmb+2wdrth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Ju) )yj6.-y7w wss1u7jwfs a8 xggzb8c xpiter, 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 p5v( bh m6 poq3he-wje0lanet 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 circulatmn o7uo6xwjmu07h)tx:a .- w ay q(o2r orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orox-a(uau h x)wotj 6mm:no.7t y0w72qbit?

  The planet Jupiter i0+1s(wqvslh+szxp8(pzkl -8zw 7h h cs $7.78 \times 10^{11} \; m$ 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. e*7wi egjt y.g yi( 1p,lr:iy;What is the average distance from Jupiter to the Sun? (The:(1 ipyye w.gljigityr 7*,e; distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)