Is it possible for an object moving with a constant speed to accelerate?i7 h r/0;yq;lq a9vcik Explaina v ;ihl;7i 9q/rkqcy0.

  Consider a particle moving with constant speed such that its accele,cjajzvu*to2(dp f/a9d:j/55 pi 3wasj j5h y ration of constant magnitude is always perpendih,j9p5dv/w5:zu d5i js fp23cy*atajaoj j(/ cular to its velocity.

  An object moves in a ci wb60yzz/04rjj/jv wg rcular path at a constant speed. Compare the direction of the object's ve/bj6/w jrwvj0 40yzg zlocity and acceleration vectors.

  When an object experiences uniji tl()yia8jpf1iun0k1)jfvga 17a;form circular motion, the direction of the accele7fu;il1i yj)ga p0)8a j vj1(k1ant firation is

  Consider a particle moving with constant speed suc8yp v/iy/v* evvl 7*fhh that its acceleration of constant magni8p/y/ v*vyhfl*v7e ivtude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a x1s5;b1 ukx8oe c /1zqyi+ k uuo9pl6; du5dhlcircular path exp b 6lxlip1kq s;8k 5uc1oz;d/y uu1xohe+9d5uerience?

  What force is needed to mil s 40x.cu9s i+csib2ake an object move in a circle?

  When an object experiences uniform circular motion, the direction of 0 nc4b)cye3y cthe net force i)3 ecy0 ccbn4ys

  A roller coaster car is on a track that fortm*tpl5trne- p.ku5 . ms 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 acuk55rpttmp l ..e-n* tceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circu21;(feaw sx wflar loop (radius = r) in the vertical plane. If the car is to just maintai;f1exfa ww(s2 n 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 vert1x l:nvkq a:9e3er z8aical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest v9l31:nezr8 :akq eaxpoint, 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 t6, gqsg n.j,mc-nk *aof radius $r$ 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 atnpntrd57a: 1kokhw06 a 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 tn 7:rw5kp6od a0n1hktime, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. *r/79zs uewzps 8nvqj3:j 7k x Then it goes around az*e zw/uv8 s9qjr7xsj3:7pkn curve of 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 cuh0;d*w z.ag6 e3eipj,5v wzjkrve 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 is equal ,j wizvewj* hkdg5apz;.03e 6in magnitude to

  Two horizontal curves on a bobsled run are banked at thee):xiru+ + las 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 x es+i+u)l ra:the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is/c5 ,vcgo8eh i not constant, but increases upward from the horizontal. Coming around a turn, the bobsle /5e gciv,oc8hd 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 paa)o 2me9gun c/th to have both centripetal ande) n agoumc9/2 tangential acceleration?

  The gravitational fou - d;,hyntvib,hc+l l1i8pz6rce between two objects is proportional to

  The gravitational force between two objects is inversely propo)pjd 0 l.rtl:vanw37q ti/1zu rtional to

  Two objects attract each other gravitationally. o;rpht 1(pk 1o If the distance between their centers is cut in half, the gravitap poo1( k1;thrtional force

  Two objects, with masses ps2. m08cu 8hhs/xzdzv f r6o*$m_{1}$ 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 cttr *jjo9rwzi7fl1l :*2ll+ wx( t, j$m_{1}$ 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 ccb9+ 1zhp hax 8a60g.fstyjx1g:0wmation.

  Compared to its mass x4tp7( )lka:gm ogj o+on the Earth, the mass of an object on the Moon is

  The acceleration of grax1gq9bo9eql3caq2v8ylt e( . vity on the Moon is one-sixth what it is on Earth. An object of mvq18ea.g t2cey(bxq99q3 lol ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weight3ye8g3 n a 2ay7crh;e/o dyt2p

  A spaceship is traveling to the (+t g9z jxe m9/jzz i/40nlopqMoon. At what point is it beyond the pull of Earth'g/pxtjm9 0oe z(i9zq n/ jlz4+s gravity?

  Suppose a satellite wer0 :5 wadh4xifoe orbiting the Earth just above the surface. What is its centripet4w0fh o :da5xial acceleration?

  A hypothetical planet has a mvq: *d3yzz qnvje:x hf20t, x:ass of half that of the Earth and a radius of twice that xqhq:v f z*v :zxdy,0 t2j:en3of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what y.iu,b p9fv t d,*5:xlqfpe*y it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Eaet 9,*.f*fdppqvi: 5lx b ,uyyrth's?

  Two planets have the same suro ;9cw ;f (swcaqgvcufe y1*45face gravity, but planet B has twice the radius of planet A. If planet A has mass m, wh c;9qf*aw5ew1 v(4s ccyug; ofat is the mass of planet B?

  Two planets have the same surface g)*ngap uh1 kh 4xjq8n) k2pxh4ravity, but planet B has twice the mass of planqn*24)8)nhh1ka up xk hg4jxpet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheric4 w-n8n9:a z (zhprxr:a28mq tz jlk9qal planet (mass M). Which expression gives this satellite'nwza4rnx -hj:zkr 9q 2(z:t 89l8ampqs orbital velocity?

  Satellite A has twice the mass of sat4zg vp 2w3uq0aellite B, and rotates in the same orbit. Compare the two satel uq0 zpwv24a3glite's speeds.

  A person is standing on a scale in an elevat rs9q2:n qhuptu.)e0bor accelerating downward. Compare the reading on the scalep uq: r9.u) s0bte2nhq to the person's true weight.

  Who was the first person to realize that the planets move in rvfqy0au-lkv)0)ax- h2-pqyelliptical paths aroundy-0l yuqa hv)-px- k)av0fqr 2 the Sun?

  The speed of Halley's se *c:d2 (um s(i 9mh2arh.pkgComet, while traveling in its elliptical orbit around the Sun9 2kpm(hr:d.hi 2asuscm*e g( ,

  Let the average orbital radius of a planet be R. Let the orbital perio+0esgz pd4u5x d be T. What quantity is constant for all planets orsdpez5 0xg+ 4ubiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with thu,yt*9nou+iy/ rzxdajb 34 i4e 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 rej+uut3 iy *dxz b4a9ynr/,i o4volution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined kh ccf.oiz/:pxi39+m8* jno qas one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What x.pm fjcck oq:+*9i o ni/8z3his the asteroid's average distance from the Sun?

State Kepler's laws.dswj9r7t +; h+f1u defq54rjq

  List the four fundamental forces inh6 umjp,hyibu* a 6m44o x*vw ic8:zb5 nature.

  An object moves with a constant speed of 30 m/s on a circular track of v(unx c xbs7dv6fs5osqz)a69cb2 (qp-2pi j 7radius 150 m. What is the acceleration of the obje(fd 7z9o 2bjsqi(7 56pvsav2-scupn6) qxbcx ct?

  The maximum speed around a level curve b;m3)e;0e:bkdua fmt es -hr7is 30.0 km/h. What is the maximum speed around a curve bd :m m tr0)eu7ekf-bhea; 3;swith twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a poinz0zk1i3sg 4 zws/v+ lti 2i2lg1efrz+t on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movin0zzliwge4s gt+f z1ziiks2v+r 12 l3/g 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from ty u8l 2,z1zryfhe axis. What is the centripetal y,8r luz y1f2zacceleration?

  How many revolutionso b2ciwfyzlu gy9- 21flqs303 per minute must a circular, rotating space station of radius 1000 m 2 sfbiyw0 133l2zf-lcgu9 qoyrotate 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 tuf;jv2p ek.8svyfu2w /rn at 96.5 km/h. What is the centripetal force on 8k; v sjev22pu.fyf/wthe motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. )pd)ckej) 6 gh b0pp)nkwb1c7 The system is whirled in a horizontal circular path. If wch7pgb)pe)6 kcn0kjpd) b 1)the maximum tension that the string can withstand is 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 strong string and w6 / c+oulebea.w(bu8whirled in a vertical circle of radius r. At the exact top of the p+ ew.6uo/ wl8 b(ubecaath 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 whirled in a vertica20:fpl r+dq 3azbazcpr(l1d 8l circle of radius r. At the exact bottom of thez rbppac 2rza(l301 dd+:fq8l 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 acceleration of 4g when pulli y( jj1b+miys+ng out of the dive.yyj b 1s(mi+j+ What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the lot;/t/q iag1y .rffj6m op is beneath him) of radius 3200 m. At the totgti jf./a ;/1mrqyf 6p 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 --iajohl98 rhcan stand is about seven times his weight. What is the minimum r ao8-lirjhh-9 adius of curvature 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 th u)wdw dai; (d;spbf7+e 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;wsa;p biu7)(+ddfdw road surface.)

  A car is negotiating a flat cudb4d7( vm+dskrve of radius 50 m with a speed of 20 m/s. The cen svd7( dbkm+4dtripetal 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 rakqp)yeei24(yj *8+a e8(mk tyqd+chzdius 50 m at a speed of 14 m/s. What must be thezyqcmq +e)* 8aidpy4e+y(( eh82tjkk 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 level curve. The c y yjt8 ud7/ tg )e4yx;l8xa,(d/jughpoefficient of friction between the tires and the road is 0.40. Wha;,yt 7uygy xp 8)dj4guej/lxd(tha /8t is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle t 0ozmbt(al/8 0v p3lolwr-,ris required for an Olympic bobsled to negotiate a 100w,op(0bt03zv- 8l rotr/l a ml-m radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bo2 fwfuye;2 7ibbsled 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, banked at an anglof6eb ka mf az0/65)nbe of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i bl. ;q7.c w1c(wojkxex7 rdph,po 302x4cm cms 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 iskm, 6a9 y*ka;xqzhu6/ ypk l*1(nf sku revolving uniformly in a horizontal circle of radius 0.50,nakmk 6qk u 6/* ;x *y(lsfzukph9y1a0
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 uniqq 8.-hm myk7gb)b4i hform rate to a speed of 45 m/s in 15 s, mgmk8 q7hhq)4m.yib- boving 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 oum0n45s4cd xin kz84hf9 f nuvs 4jo9*f a proton 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 xz 7l;ietiquj :(tj10b2d5 wwthe Moon? The mass of the Mooni7ej5xdubq( w1zi2 j wt:tl0; is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attracix7m j 8bj)*gwtive force between two masses is F. If the masses are mojb7i8g*x )wmj ved to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, as)+f591 rooi * 3wxgkzrsiu3u t what distance from the Earth will the gravitational forces due to the S9*isi5uf) r3g1rzo ouk x3+wsun 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 is+ :xw2mp b2z zkrtw;6y $7.4 \times 10^{22} \; kg$ 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 distancb0.ooju 6espll:t8wd+j zo/)e above the Earth equal to the radius of the Earth. What is her acceleration.dps/bu:oj o)8jzt +o0 l6elw due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfa,a1u6;wk*q dxqno ;x vce will the acceleratqnkvdxa uo ;*1qx;w, 6ion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at n;i2//tj z7g6az (c / yzh fq8u8ontova distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the accelerazf zaot/6;8iyo n 8/vcn(jut/q 7hg2ztion of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleraz e;ra,hvn5c+0vd d2 etion of gravity is vh;c+0a,zed 2 n5e rdv$32 \; m/s^2$. 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. 6 acs.7q1x jzwx y-9r2 nm4qyoIf the object 72c 14nom.sr6yqzx jyq-9 wxais raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kv9tdgx2af +ujqeb t85/n*o-z 9etqa 1g person change when he goes from sea level to an altitude of 5000 m? (Th n eo+ux2t fqvt8 9-jtgzqe19ad/*b5ae mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A saj (sd.pxbp)z/tellite of mass 100 kg is at a point 3r above the Earth's surface. What is t sd/zpbjx. ()phe satellite's weight?

  A spherically symmetric bzra.:alkso7h 4/v r. planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the .:lb/k vra.zrao7h 4ssurface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun ;e9z6r0ntlqksbv,p r3 t- nk ;all lie on the same line, with theln 9nbp vrs0 e;3,;q 6kztkr-t 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 the Moon. p5;xklhkt9;*u/8s0bcvee, o bi0h3;t haq wn
(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 (8cpqov2(,,wx*zo vuhs2 83pii3ywc ti.e., it just skims the surface of the Earth). What is the speed of t3(vi,2poyv8, q2 oc*u wxsit8pzcw 3hhe 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 skimsca-h7l7t t- v(9gi g0t/x wffo the surface of the Earth). How long does it take to make one rt/fg7g 0 alvt-( i fhcx-t9w7oevolution 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 suhy5qf87cn* )qn fau4a r v r:)qgj44u un-1hzkrface of the Earth. It is observed to have a period of 89 min. What is the mass of thrq1f a4hr)cku ) z7qv-gj 5n*h8 4fa4ynnu qu:e Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital dnu-tmu:wr5z j 3k . 8z;a1rnx4fmn c.yiameter 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 planet with a v-x,zor* r vu8radius of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet j(/xfw(1epq(yc oa1h in nearly circular orbits. Moon A has orbital radius r, and o cf/ah(xq1e1( yjp w(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 i(7.scp /u2jqiz*q ktf03ips ws $7.78 \times 10^{11} \; m$ 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 n15f7 xgnzk;x Sun once. What is the average distance from Jupiter to the Sun? (The z1n5x ;7xfk gndistance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)