Is it possible for an object moving with a constant speed t;q e7rgns*asq4l*ex6 o accelerate? Explai re;q7ql s 46sxg*nae*n.

  Consider a particle moving with constant speed : 5v jv2nwg 5wlxv4ho9such that its acceleration of constant magnitude is always perpendicular5x :lg9v5 hwjv24v own to its velocity.

  An object moves in a circular path at a const(*w(tn lcoa3yant speed. Compare the direction of the object's velocity and acceleration venw3 l (atcyo(*ctors.

  When an object experiences uniform circular motion, the direction of the ak-1 wrhij(-tvcn5m7 r9i8q orcceleratnv-i8cr - 79h j1r(moqwtrik5ion is

  Consider a particle moving wizm(5 ( hpo.qovqr:*y m8 /thbtth constant speed such that its acceleration of consrt m(ohzh(qo m/.:58btqp* vytant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object q,l w b9518m fk,pzagdmoving with constant speed in a circular pag8 ,kadq19mp zfb w,5lth experience?

  What force is needed 3hhja/ o9ffwsc o5i*, to make an object move in a circle?

  When an object experiences uniform circular motion, the )gqpq37o9po hp scey*nru5.5,6o .(casc ppn direction of the net forasc.p npuc *yq,69o5.r 3opsegnh c p (57po)qce is

  A roller coaster car is on a track that forms awz n;ynz8cvvexpw ,:-36ibn 4av.f j. 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 centripetalaw 8xeivv4:zb - 3fp,nn;6yvjw n .zc. acceleration at this point?

  A roller coaster car (mass = M) is on at;1z+*5iel6oters,1ik -jyze vs m x / 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 is the minimum value for mk;6ivei 11sxsz,/ -l y+*zet retjo5its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc utn23zxl sl10 tb 5gxq)/apqe6ntil it is going straight up. Just as the pl n5x ttz3l eaq2q06p1bslxg /)ane 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 of radih b5m c1d8v26n ae8kvwus $r$ 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 cusecg u+w(jxi y q9+ljr:+7fiqf87 0it goes around the same curve at half of the original speed. What is the centripetal force fc0w+f8i jlgx7e 7u9qcuq(+y:rij+s on the car as 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 cog8j*i)id u1 pxnstant 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 around the second curve, comparejug1*dxi)p 8 id to the first?

  A car of mass m goes around a banked curve of radius r with speed :j yez*cc /l0tfff1)h v. If the road is frictionless due to ice, the car can still negotiate the curve it/ 0cjfcy f:h)f*zl1ef the horizontal component of the 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*f00 umfqp 1ez1(cl gl 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 vf gm0lp* c(1qe0lz1uf. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled trackd 6de a -qp(ph:kh8gv* is not constant, but increases upward from the horizontal. Coming around a-d8g*vd :6ae h (pkhqp 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 an4a g25hux5nwn object moving around a circular path to have both centripetal and tangential accelhna wng2 4u55xeration?

  The gravitational force between two objectv)1qjt 2sz k4/bkgea 9hg ,nd8s is proportional to

  The gravitational force between two objects is inversely proportionalx8v,q,uidai tbu4,3 n8iy no* to

  Two objects attract each oth) uplnsuud9,, m(upf3er gravitationally. If the distance between their centers is cut in half, thu(lu)pus 39mfn,d,pu e gravitational force

  Two objects, with masses)( -v rdxgy*qr $m_{1}$ 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 masses e0xq8:wg3h: /zh alsb$m_{1}$ 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 gravita.et1m nd; zmu,tion.

  Compared to its mass on the Earth)onqt(dgk rjk(,6gk *, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth wha*my*bwkkku 02 t it is on Earth. An objec02* yum w*kbkkt of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves awa8n 5raelyp7/jp u2ue;y from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what poinnj48e5gm+ g)fqahsf-o .)2glh mu2i zy +y 5sot is it beyond the pull of Earth's gravig o5+)lfjzmye)+quh as8m4g5oih.2fs yg2 -nty?

  Suppose a satellite were orbiting the Earth just atry g4rw .;;qhbove the surface. What is its cer ytr whg;;q.4ntripetal acceleration?

  A hypothetical planet has a mass of half that of toje9 dccux:,t)5 +ljphe Earth and a radius of twice that of the Earth. What is the acceleration due9poctjx +5u, ldjc:)e to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on t - 2sicnav)+ethe Moon is one-sixth what it is on Earth. The radius2- e)ican +vst of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of za 0i 3ul*c/zvplanet A. If planet A has mass m, what is t0v 3liz/uzc *ahe mass of planet B?

  Two planets have the same surface 04v7i tol j3pwd 7yu,66mvloogravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet B? l3,ywto o6d o j74lpvmui076v

  Consider a small satellz1yld;c l l6/nite moving in a circular orbit (radius r) about a spherical1/llnz;y dc6 l planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the o*k t03 5vmyib(qxpv,same orbit. Compare the two sat,k0iq (pt xy5ovvbm3*ellite's speeds.

  A person is standing9gn p xvh osz/7w/,yd; on a scale in an elevator accelerating downward. Compare the reading on tn,9s /zpw o;7xdghy/vhe scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptic 9a0.zoqmmrs 6al paths arounmm9r s 0a6.ozqd the Sun?

  The speed of Halley's Comet, while traveling in itp) sdmy w7 +qot5.un;7sdbi)hs elliptical orbit around the S7.hsn+qb5; 7 osd)imy pw)u dtun,

  Let the average orbital radius of a planet be R. Let the orbital period be T. brv 8pgh css-vk s,567 What quantityc sshv6gpk7,rb- sv58 is constant for all planets orbiting the Sun?

  A planet is discovered to orbit a;7c pdgazq9t ,round a star in the galaxy 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 of that new planet be, compared to the Earth's oz7dtqga9 ,pc;rbital period?

  The average distance from the Earth to the Sun is defined as one "astronomical8ab0d3e xe; tb unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from th b8xt;d be03aee Sun?

State Kepler's laws.cdu 6ikg43lp 1.p 9vtn5oee6) olxm7u

  List the four fundamental k r-;d9ij tsxilj2t*g5/ bkb2qkl90 zforces in nature.

  An object moves with a constant speed of 30 m/s on a circularoay8ik s k wu2ao9kjq56p:2k* track of radius 150 m :9skok wyo28* iq56jku2apa k. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximhc2rl :b;6si epp l2. dt3j 7ea78ol,hter8houm speed around a curve with twice the radius? (Assume all other factors remain unchaet8p7e;l i lh3cleah , .t:b8d7sjh2o2 rr po6nged.)

  What is the centripetal acceleration of a pointyn s;74ekasjg o8+d/y on the perimeter of a bicycle wheel of diameter 70 cm when the sg74jk 8/ys;ny aeod+bike is moving 8.0 m/s?

  A point on a wheel rotating atzpp5qnv+z ow :t2rg :0 5.00 rev/s is located 0.200 m from the axis. What is th z:op gt:qp0v25zn r+we centripetal acceleration?

  How many revolutions per mi3 ay1yigku:w1m5 .h fdnute must a circular, rotating space station of radius 1000 m rotatek.1y:ui1f 3d gy a5hwm to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at o/f9 y*0di, tdrx ,blt96.5 km/h. What is the centripetal force on the motorcyc0l,t/t fiydxd ,bo *r9le?

  A 0.50-kg mass is attached to the end of a 1.0-m stringrgsv3d 53b+*a1o hy8nf kep+n. 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 strin8r1*k5s 3hbenvyn3a opd+f +gg is not to break?

  A stone, of mass m, is attached to a strong string and whirled in bd z6wdle kk-tj4 6td z9 um6nfbmg.x:t/8-6la vertical circle of edll4 -zg6 t6 b8.f6nmdxu/ j69wz d:ktmk-tb 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 this point is given by

  A stone, of mass m, is atta3nvvjab;yg- 1 ched 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 point g3jyn ;va -b1vis given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when vlat/1l 8z6xgrp2yz+ pulling out of the dive. What is the radius of curvature of the lo gx/zylvpt+ 2r1zal68op in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is f ox3 b,z 9e)bisr)7kobeneath him) of radius 3200 m. At the) )brxso k7fzb, i93oe top of his loop he is pushing 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 wppd*dsqc 7hoa -y*i4)eight. What is the minimum radius of curvature that a jet plane's ppd*pdah4*isc)o yq7- ilot, 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 howwg3;lw 8zj z6+5d rcarizontal 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 fri j3r8lgd ;z65+wwz acwction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 5 9)i:pio ,;a7dkpy:z ntr4izu0 m with a speed of 20 m/s. The centripp;ziunr ) p:kodaitz9, i4y7 :etal force provided 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. m95m wtkjnr.3 What must be the tjrmw 9n.5m3k minimum 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 levow6g7pho1jyy;c/yu q5ud9h qp x0**l el curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curupdj*0x7 ;opoc 6wg9q/q y*yhy1hlu 5ve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsz8yq m2vfo7. a0g/g7 e w(cd+kkerku*led to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictiondumg7kfw.2co(7k */rk +ayq e08ve gz .)

  A horizontal curve on a bobsled run is bankpv.0cccr sk(g2dg*pc 4uq7 b4ed 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 ab. aa0oex qf,7n angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 efs/lay4ps: 9 m 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 o dnetwv 9r)z;h-.;ql tf a string is revolving uniformly in a horizontal circle of radius 0.500 wv t)q;t.;ed-l 9rnhz
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 are 2nro.y:c u;sb5 8smzfa, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on u :.zrf5 2m8sn;bos yca 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 protoyekrqd d f,1fj)57b3jn 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 70ckoe.kw ;ha6elx09d 7-kg person standing on the Earth, due to the Moon? The m06kalh 7k. cwdex9o;eass 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 ba h04:z l(vscj(ayr.hp q8 my-etween two masses is F. If the masses are movev- (qp8c 4ha a(yzsj y.h:rml0d to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going fro, y.rvc3kd wrogjwj 3h/l iht(2apm-.nw :c :/m the Earth toward the Sun, at what distance from the Earth w -/ :vrl ykcwj(on 3mh:ht. g.2d,ij ap/cw3rwill 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 isxalywo* atg9( )rq7 lfj 634sc $7.4 \times 10^{22} \; kg$ 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 above the Eap(oy:taj0)*)dhkb,zke.a lu rth equal to the radius of the Earth. What is her acceleratiabe*o d)l0y) kaz (kp:thu, .jon due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will++ t,/ gw*cfbjzrdyo y+ :(ogl the acceleration of gravitwgy+bot/r, lz+ :(ody c+*jfgy be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 t9bxj 4aodh1 3v 1cgpi2imes the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfaccv1 idgxo jhp2ba9143e of Mars, is

  At a distance of 14000 km from some planet's center, th+w/v:)gxpm9 y614 ;q bmdjbw8 udtln ie acceleration of gravity iux bm d8/g bi9dw6lnyj;mqt :)4wvp1+s $32 \; m/s^2$. 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. txl 7b0j m/.vz The Earth has radius r. If the object is raised to j7/tx .0zb vlma height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg ps-,//xsbs 4q jokxl4ferson change when he goes from se 4blj4,-/qsf/x sksoxa 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 sa(y5y7 m88zpvn1bcvd w tellite of mass 100 kg is at a point 3r above the Earth's surface. Whab(yd7y v5nz8 c8p1vm wt is the satellite's weight?

  A spherically symmetric planet has four8)hd bstc:e p fmsmwlx2*j340 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 much would it weigh on the surface of thsw*xm2chels 8b dm 3p t04f):jis planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, wj.tey-xuv ;sra 8j 26jw*c-2q x8djm-p, lrojith the Earth between the Moon and the Sun. jvlmx 2.jjsj-o; - c xywr6j u td828ear,qp-* 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 ihx0- pc1 g7(wm8xknyMoon.
(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 circsiv )8,m py-lh/gx:xdular orbit about the Earth (i.e., it just skims the surface of t gs),hx d:/liy-pv8xm he Earth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skims the7 ee x)lq((ne3q/ w)b0tbad ys surface of the Earth). How long does it take to make one revolution abben 7)e 0(w)txs/ e3l yd(qqaround the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit wmy :v:-6mn;bpm(kg * fko;za 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? (T;:fmyp-nb :*mmk(v o; 6w gkzahe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of 6fwsm9:girmo97k x kw2xv j(6$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a ragdl8b h8n :n5ixq ivrbq3 n086dius 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 ra4qo2(t g )igpwuk. d3xdius r, o .w(p qd4k23t gu)xigand 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 orbit?

  The planet Jupiter is.h0fn . zbfxb5yg l4a( fbq+x6 $7.78 \times 10^{11} \; m$ 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 r9pay;1hb dwuyjae,-*0leq ;years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance froaa*wje;p,yr;ueq yh-0 d9 l1b m the Earth to the Sun is $1.5 \times 10^{11} \; m$.)