Is it possible for adk95o0 t5-h i:blv bvon object moving with a constant speed to accelerate? Explainvt b9k:i5bl-0 o5ovhd.

  Consider a particle moving with constant speed such03) bn n2opcpy that its acceleration of constant magnitude is always perpendicularn)y n2b0po 3pc to its velocity.

  An object moves in a circular path at a constant speed. Compare the d5-*op2k uq t+7ieqky firection of the object's velocity *q2ey57iot -fpk+uqk and acceleration vectors.

  When an object experiences uniform circular motion,e cqc,8fx)*jgfl(02yp+edoxt3 fb +g the direction of the accelerx3o q+cc ely0gfb28 df pe,) tg*fx(j+ation is

  Consider a particle r:1u i r8 -a-i,+eb1mx e 2t0nzystcxwmoving with constant speed such that its acceleration of constant m:1e2i+ut1-x e0x wiz,crysm r8n-tb aagnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with cph1 4m hiav45j a- he+r11inrzonstant speed in a circular+mi5a-hhv r4 jenzha14 p11ir path experience?

  What force is needed to make an object move dk1avr q6 ug 6fg.jvuuj0/k)*in a circle?

  When an object experiences uniform circular motion, thep4 n d.;1rbsb- zl9ebv direction of the net force lp.b;b r ze-sbnvd194is

  A roller coaster car is on a track that forms a circular loop in theb (jgc jmj/55wky4,nivj j2 2l 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 thijwb4(2 j y5nlicj j/kmj 2,gv5s point?

  A roller coaster car (mass = M) is on a track that forms a circular 6n71pqbm* lpqy;nk w0loop (radius = r) in the vertical plane. If the cqp1w nn qmk*; y607lbpar 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 vevanh6b-r jt*5 rtical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowejb6 -a*nr5 tvhst 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 -vzw50 t5ua)o*hwp a jradius $r$ 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 89mwvlxk 9d+in h2li,constant 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 around the curve for the second tilmik 82, v +dxhw9in9lme, compared to the first time?

  A car goes around a curve of radius r at a constant spd50 l0y4 ttzz*otio i edt80h9eed v. Then it goes around a curve of radi*t o5yzhtie90o4tl dd ti00z 8us 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes aro) as2nt rfr10lam*x4qund 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 the normal force on the car from the road *rlmfxs 10n2at ra 4)qis equal in magnitude to

  Two horizontal curves on a bobsled run are banked af7k-fx /79p ht(kif3wfxes c4t 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 fp fw-3/kh7kxsff47e x(ti c9v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympu2b3 v :o 4zdnz 4.iq fnm(r(pye34lqric 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 turn. Why do thqn: zrl4(3vfqpm du4 oye2r i(4n3.zbey do this?

  Is it possible for an object msfk i*y .7p734zpmo lsoving around a circular path to have both centripetal and tangential acceleration? fl.p 4s7zoimysp3 7k*

  The gravitational force betwee69b d3d z+cr.; zn;0nqxtohotn two objects is proportional to

  The gravitational force between two objects is inversely prop7r cpg/*ccfba4 1b up,d 14gdvortional to

  Two objects attract each other gravitationally. If the distance be-cjae f; cm 4-)ra,q1vrpry;btween their centers is cua-,)c;jmev4fcqr -r1 barp ; yt in half, the gravitational force

  Two objects, with masses trtr ;oe2 n 9pvaf//gns+2e)c$m_{1}$ 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)d: hbsh q//nuec0hfb1wpb y l3)7jp sses $m_{1}$ 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 uzdlkqzjj+0 40niversal gravitation.

  Compared to its mass on the Earth, the mass ofnkjk 9)n*e/v+ fsavs5 an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An0vbp6+rmz2y xl q i)2l object rxi20 q) +pz6ylm vlb2of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the4,xcarxn tjl3 -gr 9y0 rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pullf+ :iswsau,0q of Earth's gravsua: q i,ws0f+ity?

  Suppose a satellite were orbiting the Earth just above the surface.pv08x7 wdfd4x What is its centripetal d8dxxf0v7 wp4 acceleration?

  A hypothetical planet has a mass of hk-mmmf b.r.f7l .v.awalf that of the Earth and a radius of twice that of the Earth. What is the acceleration due to graw.b valm.km -rf. fm.7vity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moo-0c -j0: wjp dtaw.wzvn 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 comparatwwp.d : -vw-0jjc0zed to the Earth's?

  Two planets have the same surface gravity, but planet B has twx)6ksv/ezh r .ice the radius of planet A. If planet A.z/ shk6xr) ev has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planf gvyp4w .49jcet B has twice the mass of planet 9 fc.4 wg4pyjvA. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (rad)lu5szc(40su xog 6ehius r) about a spherical planet (mass M). Which expression gives this sgeul u5)xhcsz0s o(64 atellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and ei uswa61:fr+3e mgh2rotates in the same orbit. Compare the two satellite's speem:6ag+h 3w2fuesi r1eds.

  A person is standing on a scale in an elevator accelerating downwaru h 51 xpur9q:eco/2ood. Compare the reading on the scale to the person's true we rp 9xe5:c2uoh1quo /oight.

  Who was the first person to realize that the planexi3 hwn8nta ( ht.a9h-ts move in elliptical paths around the Sun iwa.ht-38xh ah9t(n n?

  The speed of Halley's Comet, while traveling in its ellipticall7ij ku 06cbv5 orbit around the Sunkv5uli6c 0bj7,

  Let the average orbital radius of a planet be R. Let the orbital ,tofn 7r vpi3icflc gyu,) :/.period be T. What quantity is constant for alfc 3rtn:ul, f/ g p.i)ocyiv7,l planets orbiting the Sun?

  A planet is discovered f/v7 vn,,kyd)rz z:xkto orbit around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that stard/) zkv7:kz,y rv,fx n 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 Sun is defined as one "agvnm;j 0ipf21zjl7u,s2 cos )gj;vr7 stronomical unit" (AU). An asteroid orbits the Sun in one-third of a yea sv,0gc vj7 ;i ul1mj2nz 7f)goj;2prsr. What is the asteroid's average distance from the Sun?

State Kepler's laws.w7j5 :qukkn t gyk+94t

  List the four fundamental forcesq2lvk4p ju irszkkt 7 r-nwqa.39 98y) in nature.

  An object moves with a constant speed of 30 m/s on a 6 e6gd:8fxip) z/ssli circular track of radius 150 m. xgz 6dil sfi/s:6)e8pWhat is the acceleration of the object?

  The maximum speed around a level /3 wroqzv wa/e 6rl6o6 7oyh5scurve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged /56 wo hr6a lso3ezwqy7v/ro6.)

  What is the centripetal acceleration of a point on the perimeter of a d0p/z9f 69 rrx+opqvobicycle wheel of diameter 70 cm when the bike is moving qprd9xpo +o rv 9/0fz68.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 mvmht 0ok *d y:hfdyg*u w762)l2s)buf from the axis. What is the centripetal ag )yfmu*u7: 2*h0lwk d) y2bs 6thvodfcceleration?

  How many revolutions per minute must a circular, rotating buvf( p+g+j+lpx,w0 u space station of radius 1000 m rotate to pro+ ,+bjw +ufg xvl(up0pduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aroundv:o vt(5zbm t8 a 13.7 m radius turn at 96.5 km/h. What is the cevbv zo t:85t(mntripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end y s)ta0e3qz8v/+nknjof a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is08a nvtsn /yq)ej 3k+z 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 stro4ayfpj3yo *l ar,qt2(1gii ;phz: lz.ng string and whirled in a vertical circle of radius r. At the exact top of the pa1gfoill(i2yz:. p patjhzq3r; a, 4*yth 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 attached to a strong string and( sb ftoxu*k 8tmzs q(n4u5-.p 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 ths( zknt(t x-op 85buqus 4*f.mis point is given by

  A jet plane flying 600 m/s experiences an acceler c. xl:lkzx k8i.a*ba93iwxd 5ation of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyklxaz39:5w*8.abkic xl i.xding?

  A pilot makes an outside vertical loop (in which the center of the loo(t l(,)5c ngi(,3piupl9 c pw u)fvnnqp is beneath himi puc5 , qc9u(wiv(pll3t)(gnfn ,)np) of radius 3200 m. At the 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 aboutwa edy*zgy a s9961i y7p,ppm. seven times his weight. 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 250 app,e71p*z6ys9wm yig .a yd9m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curv.haz wu ;zeh-1e with the tires on the verge of slipping. How fast can this car ro -hh.;zeu zw1aund a second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20q( r5e 6o0xoao m/s. The centripeo0(e r 6oaoqx5tal 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/ v+hqd a4fuxv0ybkm 0 :/7*glcs. What must be the minimum coefficient of friction betweenl 0 gh fkvuyd0*x7vc4abq/m+: 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 coefkns gj z.huovk52gr+ )2dk6:j nr;bm1ficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay o 5r:nkgkj.g2bdnh )+6 1k2r voj;su mzn the road?

  What minimum banking angle is required for an Olympic bobsled to;bgu/kpwmu jh y:/8 zwm)m*, i negotiate a 100-m radius turn at 35 m/sz* b; i8 /mkupwhm jwu):mg,y/ without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run iy- exesy-z 2k0s 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 kuox3h*ysonx: cq8 ))- jfs.dm, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m ijt76fh6+w -+pzmztlls 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 e /xu-/mmx uu/d( x/hxmnd of a string is revolving uniformly in a horizontal circle of uum/-x mux//xm(x/h dradius 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 pit area, a race car acceleratf j +d/w9t+avwip1oezzgn irp)sex+ (2 0:nr-es at a uniform rate to a speed of 45 m/s in 15 s, movingaxin(+)wz1 d:oiv+f 0-n + grw9rjps t2/epez 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 proto/ isrp6c m5cj 40/nr clky x,y4obg;i,n 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 omsm/a r*jivpn*(bz - (n a 70-kg person standing on the Earth, due to the pmaji(/b*-*n mrv s(zMoon? 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 masses ar5oqxnf z hg.)8y2h2xkqi;c9ve moved to hal x;gyq2.fh85nh x)izvo2 kc9q f of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the z / 6szxt6zj/ySun, at what distance from the Earth will the gravitational forces t/xj 6/z6sy zzdue 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 ts1 bmipivd*8o-ay96k9 )ix)s - l czris $7.4 \times 10^{22} \; kg$ 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 ll .1i11 tzybmqws ,c6above the Earth equal to the radius of the Ea 11ly1,b6ismqtcz .w lrth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distahjsmo.-c(7 hq nce above the Earth's surface will the acceleration of 7hhc. sj(qo-mgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars uo+4vu * cx4tsat a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration+x4outvs u4*c of gravity on the surface of Mars, is

  At a distance of 14000 km from some o 0q: jak tss1l /4 impce9d:l g*mneu+q98y4qplanet's center, the acceleration of gravity is q1 maeij9084kcony lsq e +:* mspg/ 9d4uq:lt$32 \; m/s^2$. 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 ha gq zhp0)+g9yts radius r. If the object is raised to a height of 3r above the Earth's surface +tp)qgg09hzy , what is its weight?

  By how many newtons does the weight of ;le 1m: z b3dvjwa6o9va 100-kg person change when he goes from sea level to an altitude of 5000 m?mj wv doa6vl9 :;ze31b (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mas79wcetls w6* nbw+:eds 100 kg is at a point 3r above the Earth's surface. Whats7wt* :lb ee+6dw9c nw is the satellite's weight?

  A spherically symmetricdm4jni ) m+rt2 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, ho4+m njdt m2)riw much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth2ky:tad*dw c6r gcw/2, and Sun all lie on the same line, with the Earth bet /c cwa k6dr*d:2g2wytween the 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 transporse7i. 5cbf -y.fx bb/mted 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 ( t ;v8p hx*mo9g*,zzt)hjyql skims the surface of the Earth). What is the vjhz, (yht;mq8zpl*tx) g *o 9speed 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.cv )u z6ac)1iq v46y.mh*leamprv p : the Earth (i.e., it just skims the surface of the Earth)..evh 4p z6aq6u vc.vr mm1))a cyp:l*i 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 circularx:d j5uvhlaz9v o :mm 6vv;-i0iz :f+i orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. Whatd:; oa+:hvvv9-zu0 if:6jz5ivm xlim 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 diametnr 6yjmfnsj4 +c)0i6per of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon o+wh ut3b: )ycpj a.q5sf Jupiter 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 orbita zkz(2 h7y2lzoifxk 3:l radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it3k:yzlz2 2x7z hkfo (i take moon B to complete an orbit?

  The planet Jupiter ismlk k(hy b5qj4p x1crvii65zp6v e 6)8 $7.78 \times 10^{11} \; m$ 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. What is the average ;cmt u:a9ydt5q uu1 8h2iwb3l4 xs 4ofdistax4c3u18 fmui4 ;bql hydatows:t92 u5nce from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)