Is it possible for an object moving with a constant speed to accelhty clf/:d - .fa+ccu+erate? Explain.c.:cahcfu ++ -dytf l/

  Consider a particle moving with constantrnvi/ja0;rop j8 i/* i speed such that its acceleration of constant magnitud8*pioai ; jv i/rr0/jne is always perpendicular to its velocity.

  An object moves in a circular path at a constant speedz r /vm*xjqkxr ,uses, c+33gzz(8kf ;. Compare the direction of the object's velocity and accele,xqz kr;m+uek* cg/ jr,xz(zfs 3s3v8ration vectors.

  When an object experiences uniform circular motion, the direc 73uraeg+ cr/fi (p0*mkw (zqvc/pc v2tion of the acceleration is*cwe q/ka 3 (2rcrpiv/(v+ 0uzm 7gfcp

  Consider a particle moving with constant speed such that its acceleration ouybkeeqt2 ic*1 j2g.;n y:g 4nf constant magnitude is always p1nt: nek yj2cgq;.yuib2 4ge*erpendicular to its velocity.

  What type of acceleration does an object mx-xa 2;;vsorx q3d:mo oving with constant speed in a circular path expeq o x:rxv2xdm-osa;;3 rience?

  What force is needed to make an oe8ax r)ax/tb /:u wqe6 i2bt,rbject move in a circle?

  When an object experiences uniform circular motion, the direction of the net t1e/*2rdo b jn68w lwdforcewdj16*w2 nobt d8e/lr is

  A roller coaster car is on a track that formsh.xrt3un e63e7: o ivr a circular loop in the vertical plane. If the car is to just maintain conrne6 tuhior3: x.73evtact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is om2h7axu4c - syjt:h-gn 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 is the minimum value for its speed at-u xjstyg:hm -7h4ac 2 that point?

  A pilot executes a vertical dive then folyc.kn ;: x) ggvm;it60ljocv 6lows a semi-circular arc until it is going straight up. Just as the plane is at its lowest po;:nmt 6c)l;.6vv kgjo0yicgxint, 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 ryc 6ckue r;q7:u9goj;adius $r$ 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 cy*pjde/dz7 +y onstant speed v. Then it goes around the same curve at half of the oridy/j+ p7dyz e*ginal speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curv, wp y(8h7s. ialws19d.wkjfr e of radius r at a constant speed v. Then it goes around a curve owkpwy lh(98sfrs7i d ja. w.1,f radius 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 around a banked curve of radius r with speed v. If the roa*r m8cg ve,ke+d 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 is equal in g8*erkve+c,mmagnitude to

  Two horizontal curves on a bobsledq89ybl/d /q4 sa :adxfu0.ixv7wo /h r 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.qfxd / 9/v4/:0obihdr7ax la8 wyqsu. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, bu/3*gsye)n e ncy j:arx)g3t0k t increases upward from the horizontal. Coming around a turn, the bosen3ytgkc )je/*) :a3ygx r n0bsled 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 movin6 6 s5os6beicw(gpmt lz wbxz; )5.ii,g around a circular path to have both centripetal and tangential accelei5w6b;icswio) lxs e 5z6,6gp.mt(bzration?

  The gravitational force between two objects is proportit(6u(h7 qk ks;*cwqqecp6r-hf b)0y monal to

  The gravitational force between two objtdw nkb3vsf8/uwh,43/fzwmdr+ . fh/ xh s)( qects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their5k27obd:y mbg centers7kmdy 2b:5bo g is cut in half, the gravitational force

  Two objects, with masvz8o/oe2 oc9bwugw49 ses $m_{1}$ 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 ycad -oqs 9e3v2ax(e8 $m_{1}$ 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 uni ) egfho4tzl3zy7zyww66 ey4,versal gravitation.

  Compared to its mass on the Earth, the mab.b4+xap,h2w,71q pkhs8fvi ft ;k+i.n jif oss of an object on the Moon is

  The acceleration of gx9d ,*wv/pa2 uk sxu-xravity on the Moon is one-sixth what it is on Earth. An objx kx ua 9pvd*xw/su2-,ect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fromguna 8ey5/aq 8 the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pullozc3 x+x hhu.1ehk 5b6 of Earth's graz 6hhe c3bohx+u.1xk5vity?

  Suppose a satellite were2 ply2 9)v2gqek4ouw i orbiting the Earth just above the surface. What is its centripetaw 2k)leogu 9yp q42iv2l acceleration?

  A hypothetical planet has a mass of half that of the Eapz v6 wct4zh+83ko giw p0g7a1rth and 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 3ghza6 itw8 1vwpg0coz +k74pat the Earth?

  The acceleration of gravity on the Moon is one-sixth whjz9;.2mrid4e+ iehpi at it is on Earth. The radius of the Moon is one-fourth that of the Earth. What i;i.j mie4zh pe+9rd2 is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B s8m(.n3nw(e)vlnv m*u1 f oi lhas twice the radius of planet A. If planet A has mass m, what m)iu*mn s8n3llw.(fnov 1 ev(is the mass of planet B?

  Two planets have the same surface gravity, but planet B hat))2om/d0ya d c8:nhy .as9* j dcjxgxs twice the mass of planet A. If planet A has radius r, what t)y8n./a0s *jo9dcmj dcxh2 d:) ygx ais the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) a yf-o;):k 9wn 2vy c/deiuunh1:j2ois bout a spherical planet (mass M). Which expression gives this satellite's orbital v yo:f cd/yhje1u 2)uki2inon :w-sv9;elocity?

  Satellite A has twice the mass of satellite B*c(5r. zo yp8r ,ef2ymbfnu1n, and rotates in the same orbit. Compare the two satel rcpfy.1r2*8omb unz (fy,n5elite's speeds.

  A person is standing on a scale in an eln 9ksa muci8q1i 0yr**5 pe3uaevator accelerating downward. Compare the reading on the scale to the person's tr yse0uk cip*158qra iau *nm39ue weight.

  Who was the first penymd( r79wla4 rson to realize that the planets move in elliptical paths around the S9m 4 wryadnl7(un?

  The speed of Halley's Comet, while tri ) cnl-uz0gcn ;kq6*javeling in its elliptical orbit around the Suln icq ;*ukz-j)6n0cgn,

  Let the average orbital radius of a planet be R. h0 hbl 3p9cjm0 Let the orbital period be T. What quantity is constant p 9cj bm3h0hl0for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the gaps4bpz4nwk38a1 3 g abqn6m,dlaxy 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 4k ,pz81sp43d3bnqaamnbg 6w 's orbital period?

  The average distance flv hak4a 3//(gee9u tfrom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What ist g3efaa/k 9ue/4lv (h the asteroid's average distance from the Sun?

State Kepler's laws.9z8p 5xz-b fi)wtu(h u

  List the four fundamental forces in nat .9co4c ;k*gq v2vafpcure.

  An object moves with a constant gugptb/kq*yf95f1k1 3 oti) pspeed of 30 m/s on a circular track of radius 150 m. What is the acceleration o yug5 f1b)qof*ki9tg3 1 kpp/tf the object?

  The maximum speed around a level curve is 30.0 km/h. What is rmmp v85(3x4z dbc1, jjoowi3the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged. xobjpcim3rz351(mvo 4,wdj8)

  What is the centripetal acceleration of a point on the perimeter o;bpz vbub)x6vnt 5pi m hx g-(nv77-q.f a bicycle wheel of diameter 70 cmzinnx v pv(-ugbh.b- 5mq7bt7 6;pxv) when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 t 9wa w*tkan02;i;vy8 ai. zpk0jpdc;rev/s is located 0.200 m from the axis. What is the centripea. 29;0wwkdpv8ipka; znt0;acyt*ij tal acceleration?

  How many revolutions per minute must a circular, rotating space station of rada flei ;( svtv p2vd.zz,m)*pu/fd-1e ius 1000 m rotate z.(vfl s/dmp-;ve f*zv21ut adip) e, 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 tu/ y/mj9qnbjk5 rn at 96.5 km/h. bm j/ q9jkny5/What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attachednev /ib5e4 5cz 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 witci5zveen b/54hstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is att:9h pth ; x t *wy.ozy7aud6t0qfg*l0fached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is9zog hf0 yp 6talf*xquyt.dht;w:70* 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 ste1+v1c2)n dklct3po zrong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the sl +kn)3zt2v1o1 cpcedtring 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 acceleration of 4g when pu iwak nm30/0bbek+(kt lling out of the dive. What is the radius of curvature of the loop in which the plane is flying 0kn+bk bmwae(i 0t/3k?

  A pilot makes an outside vertical loopav kv7)2cl.pn (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing dowv2n p7.) lakvcn on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot j6fc(hz yi)1p can stand is about 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 2 61fyjc(h)piz50 m/s?

  A car traveling 20 m/s rounds an 80-m radiu*.yzp l*h dvn3 qocd,*s horizontal curve with the tires on the verge of slipping. How fast can t 3coqny ldp*.v h,z*d*his car round 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 20 m/s. Tflqw t-m-./d jhe centripetal force provide-mfq lj/tw.-dd by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radt f09o ynfav-l4/n e;wjphi7t0l a. 0rius 50 m at a speed of 14 m/s. What must be the minimum coeffail- rv0 w0n7tt90npjah/f; .f4 loy eicient 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. a6 of0ii)dkiiz 3lmz + w9ng8;The coefficient 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 ow zdigi lfmn+;60 a3z)k89oiin the road?

  What minimum banking angle is required for an Olympic bobsled to nego5 vki a,-ds65+j /9vqydwfjhctiate a 100-m radius turn at 35 m/s without skiddin/9yfc+ djq55dkaj is6v,w v-hg? (Ignore friction.)

  A horizontal curve on a bobslqnc .mz t;0. :,fll 22pgcuxoled 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 radi67) oe,jg5qnt ; hvqxpus 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ba 54axnuds i4ea izckc:623, zqnked 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 vh.6 2h 1 s5ysrsr+jxyuniformly in a horizontal circle of radi+ 1ss 6s2hyr xyhvrj5.us 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, w fiq bp; om)r yw3ez. dm;+a0z(yx8c;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; m0q xeciozfw)8(bra+ wd y;m z.y3;p 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 pe fb hq49qtqr-n()e6 jroton 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 persony1 v9xl;kfda:8k p j(w standing on the Earth, due to the Moon? The mass of the Moon isk 1vayl(9f wpjxk;d8: $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If the maqatihr3hj --x1y.nn 6weg n*9sses are moved to half of their initial qhw yx t3*rn6jhag- nn-91e .idistance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward tdv6+w;mb(yg t he Sun, at what distance from the Earth will the gravit btv(gw m+6;dyational 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 c/b4vjfwj a 0tp6:lp;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" a9 4;jkx x7rzr)hnz uk*t a distance above the Earth equal to the radius of the Earth. What is her accelerat)9u74zrx;x kjhz*n rk ion due to gravity?

  The radius of the Ear2idw jymwm8(n u i5/ulvpke)8sg1e5e* 0 xc) pth is R. At what distance above the Earth's surface will the acceleration of ps2xwe )5/8ie ej1 *y5 cm0)dv8kp w(ulmignugravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at j 0ekp6cqp q39a distance above its surface equal to 3 times the 6 90pek3j qqpcradius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the ac/d, djuy8lq5dceleration of gravity qd/ dj85,ud lyis $32 \; m/s^2$. 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. T 0cjvg0(ot kyxw b2)s(he Earth has radius r. If the object is raised to a height of 3r above the Eartyc(o (s2 tj gkw)0bxv0h's surface, what is its weight?

  By how many newtons does the w ns al vi-o)1gz vd27:-)lmnqjeight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radiu v-l ) mgnlv27zdja:sq)1-nios of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg iswcq5g0kzz t x.u/h 3c, at a point 3r above the Eartk ,0cuh.xg5cqzz3/ w th's surface. What is the satellite's weight?

  A spherically symmetric planet ha+oinx. .kswg+s 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,i+n+ .ok gs.wx how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie ot6 ejm -x.r m)+3xvxpsn the same line, with s6)- jxtmrx mx.+e3v pthe Earth between 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 transported to th/9 vc:srsn 2abe 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 smn lhlh 39jgm2oz8om* t:utq87*e6bekims the surface of the Earth). What is the spel*gtmh39oe 28tunm:76*lj em oqz8bhed 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 th p6gl,bbsw2s7 e surface of the Earth). How long does it take to make one revolution aroundlpssgb2w 67 ,b 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 nuid 0guj +muod-5cq(x5n88y. It is observed to have a period of 89 min. What is the mass of the Earth? (The m (-d 5dic+u yn5xjmu uqgon808ean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has 5zgi ea; 6g6rdl .l-inan 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 Jup;m-u(- kag ,3cgh3z ;psf 94cvqvwcyjiter 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 has3n(yg wu 3b/qg orbital radius r, and moon B has orbital ry 3u3q (bnw/ggadius 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 y6 +kjsm;lln )$7.78 \times 10^{11} \; m$ 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 Jupiterwp: 7z (5l2m +udujo y72 lukkk3nczv. 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (Th:7 mzkl2+ncdk23lv5pou(ju w yk 7z.u e distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)