Is it possible for an object moving with a constant speed to accelerate? *jcfrq ,ez6b28(sk ob Explain( o,e6zs8 fq2kr*b cbj.

  Consider a particle moving with constant speed such that its accelety 9cb+lxg2 cctgqz5 p).wf4) ration of constan5t)cc4.lpggb+x) qwty9f cz 2 t magnitude is always perpendicular to its velocity.

  An object moves in a circula,4v waoves7n: r path at a constant speed. Compare the direction of the object's velocity and acceleration vectorsv ,ns4o:vwae7 .

  When an object experiences uniform circular motion, ku f1/swatqu4+ lk98wb :wv(v the direction of the accelerfwaqbk8wvs+tl/ v:u1(4ku w 9 ation is

  Consider a particle moving with constant speed such t , 3-ts,aaf.,ttzw0jekaq2ysbs ;8 m xhat its acceleration of constant magnitude is always perpendicular w zks, se ,q;t- xym0 3bjatf2sat.8a,to its velocity.

  What type of accelerationc8nb 9r 9gm7as does an object moving with constant speed in a circular b8sr gca9m7 9npath experience?

  What force is needed to make an object move in a circl8uy 9 7qp4gmfue?

  When an object experiences uniform circulakvqs e(r,p4268 /qs w/klbabw 46tcgbr motion, the direction of the net force iwk 64btsbpa/b 2qkc gle 8 r/q64s(wv,s

  A roller coaster car is on a track that ;,)ox5 eect ic(ox-5zvfz;rk forms a circular loop in the vertical plane. If the c ivf k;xe,c;t(eo5c rx)- zzo5ar 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 (ma679)ue-b,r ku+ stz kcnta 3max4f t/v 89gpizss = 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 3 x+b6tezrstkv/ u z8 p) 4kit9a-mg79fa cun,of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical j+*uxjlv x.) ,fjny q:dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its low), jx ly:.fjj nuvx+q*est 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 radiusb cmj5;s74ubp $r$ 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 ic t zceo1; cce7x94d(ar)w fc5t goes around the same curve at half of the ore4cdtewcr zc o19 7 caxf5c);(iginal 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 curve of radius r at a constant speed v. a89rb:8t o:n9grmq gl Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around t:a99 bn gr88torqgl:mhe second curve, compared to the first?

  A car of mass m goes a r3h2hu71mv(ncuozk 3round 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 forc2um3co hu73 krh nv(z1e on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angl84 n : cc1ucoe+n)0 mxyckjca/wuu -/ty/(wspe, but one has twice the radius of the other. The safe speed (no friction needed to stay on the -k c1c)wn4cxu:e/t w8ny o/u+cusja(0 m cy/prun) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a t.va i* )locbw0t(i ;fkurn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobs(l o.vaci*b i0wf; tk)led 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 th0dqn2:w8 ta co have both centripetal and tan8tq :0 c2adhnwgential acceleration?

  The gravitational force between two objects is propor42q.4bp tb3*w nhvzsxtional to

  The gravitational force between two objects is inversely p8nr vt(5 wp-kdroportional to

  Two objects attract each other gravitationally +j 9wleawgt/qr1j+; x. If the distance between their centers is cut in half, the gravitational for1xj tg+jea9+ qw ;/wlrce

  Two objects, with ma .pfu/pjm 1x*jx(r6 96hz-7m p dkcikfsses $m_{1}$ 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 masxc;st5fk ynm/i wz2i3 5w,o9ases $m_{1}$ 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-v0h3kory: phe p8 m9kkk-1qktion.

  Compared to its mass on the Earth, the mass of an ob cgn/*uylt(o i x88r:p.pgv+r ject on the Moon is

  The acceleration of gravity on the M/e,.v3ff oy -th. gnzzsed.m.oon is one-sixth what it is on Earth. An object n s.zm/ed.vte3.o .z-hg,f y fof mass
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 e9ot:hg*w+ zp*g4 gc zweight

  A spaceship is traveling to the Moon. At what point is it beyonpmv.f+.allou v )c4p,d the pull of Earth's gravitymvv4upalo lc+,fp. ) .?

  Suppose a satellite were orbiting the k2j dxjr+q6luf 1nn)6Earth just above the surface. What is its r61 l6jjdfn)qn+u2 x kcentripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and scvrj 5b 9hed76v. 6gda radius of twice that of the Eart5d rg7evsch j9db 66v.h. 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 -swmei8 b,: v)zez68wou; kx jMoon is one-sixth what it is on Earth. The radius of the Moon is one-fouri6)mz;xek 8 sb-,we vou 8wjz:th 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 r) * / szb tt*l;r82rtdocd0cqpadius of planerszc8 / dolp)2 q;rtbctt*d0* t A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, bu5 egjb/, )y0 x(e c)lknuaars(t planet B has twice the mass of planet jca eglk(0eu r,/a5 sn( x)b)yA. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite movu+fkp 89a o(ksing in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's o 9kfpa+ku8so (rbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in tc8gwkd 3a(i34sa ha8 the same orbit. Compare the two satellite's speeds.4c 8a3disw ta(kh38ag

  A person is standing on a scale in an eleou6k56pzx+d8 rm0)uc aj 0spkalu8 (dvator accelerating downward. Compare the reading on the scale to the6 upu kxul 6o0ma p+8(8jc5z r0)dksad person's true weight.

  Who was the first person to realize that the planets mo 3c.(l fykjry8+dte )dve in elliptical paths arj(k8+.) rcdd etlfyy3ound the Sun?

  The speed of Halley's Comet, wh 9 n;p5gy-q:h-ij81-al mz ku8w/ddktwv*bbw ile traveling in its elliptical orbit around the Skwtu *dyv: - jbl 85/1- ww8pd;bmakz-9giqhn un,

  Let the average orbital radius of a pla lo-vvu2od3z 1net be R. Let the orbital period be T. What quantv u-oz2vlod13 ity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromedai(ji,sv, spo ml,:p1r*e*c cr, with the same orbital diameter as the Earth around our Sun. If that star hao,lv,rr*p: e1ssm,(*icic jps 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 tomjsehwtc, 76p+n2 aq+ the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is7+s6mq jae w,c2h tnp+ the asteroid's average distance from the Sun?

State Kepler's laws. 3s ;kw *gvpva 3cz;7vygpjmn7p+s+t 8

  List the four fundamental forces infu 1r*zusy* iz-3eu2)a/fg ra nature.

  An object moves with a constant speed of 30 m/s3ys6p t8 dvh,gg9hvz8 on a circular track of radius 150 m. What is the acceleration of typdv8 s8g39zh h 6gvt,he object?

  The maximum speed around a level curve is 30.0 km/h. What is the m+,qn*( mke-myfxw0 j9t7ml5zyzt um :aximum speed around a curve with ltf e 5z,ymmj9n(07tz wyum:x*k -mq+twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the2bnb65jta ez :+ nyghx*ai c (9guw/y0 perimeter of a bicycle wheel of d 6 e j/g*5ya9n0g2yuzb nhiw(t+ac:x biameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locatecyz 2a) /d z9e)bwsi-jd 0.200 m from the axis. What is the centripetal acceli9 s2) ebz/dzj-c y)aweration?

  How many revolutions per minute must a cikh 5k +u;oyjl0 /cc4ttg9+uvyrcular, rotating space station of radius 1000 m rotate to produce an artificcc+k /y 45hluougtkyt;9 0 +jvial 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 9ou1lok4jm 8:t s;s)zf6.5 km/h. What is the centri:loj84tf) m ks;ouz1spetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string.q21t/oj) z);syg+ fv2w0p:q cjv wdcm The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is tc1/qp2y)tf+ 2o; )wvmgj 0wzsv:jdc qhe maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whic+i,w8kccl7 rrled in a vertical circle of 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 thi8kcr,7ic +cw ls point is given by

  A stone, of mass m, is attached to u vjyxbtc9 9y5/ x,i.p*cff7aa 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*xbv7 fup /5f,.t jc9ixcay 9y weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences azpdt z(/pl z*t 6( q*oby dh3zg1nxk-;n acceleration of 4g when pulling out of the dive. What is the radi(p*zdno( 6dqh/1z-x;bzzt yt3*kpg lus of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop ( pjue6/.ocjx k.)xqn012:xs7. fb qqbhy5lxu in which the 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 his normal weight. How fast is he goin qu:/)yecb x7jbqhu. p2s61x lqkjxof.0.nx5g?

  The maximum force a pilot cqc5ag)u)-dgyh +wi7udnt44 san stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's piwu5-)dgadcy)h +n tgi4suq74 lot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s round.ak47g pvb0m3tes b 4hs an 80-m radius horizontal curve with the tires on the verge of s4pgtkb bh7 a.e4vsm03 lipping. 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 road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. tl8c/y/qtx b5etmb1/The centripetal force//5tbq1yc tt xbe8 lm/ 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 speed1 5b.-u(b b /qbzrzvq aao2)hkmr(,ha of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the tur,(raam2z q oh5za)kbbu1vh/rqb. -b(n?

  A car is moving with a constap 4+ihit197a p/eia p6rctb*c )dwv8ent speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is thb 7cep )i6pavhta1 rc*8 iwti+/4pde9 e minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to nu0 nf(pdv0 sxx+ztc0(egotiate a 100-m z0duxtfnx(ps(+ v0c0 radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ru2dv7 zc0;erw kn 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 7e9g 5wb-0cyuwh eqt9 q6z3r jthol2dg+5s*y radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 806jwttu v+ukic8 6lt0, 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 of a string is revolving ui2sqddd4dm-/n 1 ga9sniformly in a horizontal circle of radidd 19/nm-qgdsda 4s 2ius 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 accelerateqpka.8 z6 e j2zm qj*vnkd6/n;9u: eqhs at a uniform rate to a speed of 45 m/s in z.*8j;6v6nmne /qqkuaeqkd h :29zpj15 s, moving 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(x*; e6pv03u .hgenssxt* ulr of 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 gravitationc5s,d9qdzvx re3 k/2q6m3 nqu 1 voyp9al force on a 70-kg person standing on the Earth, due to the Mo9xo1cpsq6 v5dz yqe/m9kqdv,n 32u3 r on? 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. n g*+4:rnksj m If the masses are moved to half of their initial distance, what is the gravitational k*jrn nm: 4+gsattractive force?

  For a spacecraft going from the Earth toward the Sun, at what dicsovms (i16:seaerx v:)9 x6 wstance from the Earth will the gravi a 1oe w:6ir(ssvxe)mcvsx:96tational 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 is 7yzvhl: 5mwbn4c y/e*$7.4 \times 10^{22} \; kg$ 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 fz l 1pof9-silfl0( 7efor a "space-walk" at a distance above the Earth equal to the r zil9op 7slleff 10-f(adius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will r1s74oa hlf6e the46rha 1fl7 soe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 time l/wal+ mfxg4q1or06k s the radius of Mars. The acceleration of gravity of the satellite, as compared to the accele lqg/k+flxo m460rwa1ration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, nj 1(-acp/ 5: jtbsgcpn0h4 vbthe acceleration of gravity istjvb: p/1p-0cnhn5bc4sg (ja $32 \; m/s^2$. 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 Ear:by-zxv3 (lcy ia,4 zrth has radius r. If the object is raised to a height of 3r above the Earth's surface, yl 3b,zxzvic(r a4-y:what is its weight?

  By how many newtons does the weight of a 100-kg person chamdn 2r( wss:( qzfefi8ei*7 i:nge when he goes from sea level to an altitude of 5000 m? (The mean radius of the En w:2fi 8mze(rq sf7:ei(dsi*arth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r abik1* fd).fyzbbl4 thze t3 -;uove the Earth')fet1h*fb iy lz;-bk 3tdzu 4.s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its ral+ q 011 rak)sskwt*rfdius. If a jar of peasqa r)k 01fswk*+tlr1nut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the samegyil(hqj+-k *hv s1s ; line, with the Earth between the Moon and the Sun. Tvl(sq +yij;*-gs1h khhe 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 Moomr 2fphyxqe6s: cep8) j6 7ae(n.
(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 j+/d +*i lz7y xsa8viv 4pz0jyxzcl.6 xust skims the surface of the Earth). What is the speed of the satellite? (The mean radl zdz47 6y0z*+sxl+xv/8jp xi .cavi yius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it juenxehluw,ab w gm;97b 7 az:8(st skims the surface of the Earth). How long does it take to make one revolution aroulmb7:anzaeb( u79ww e x,g8;hnd 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. wd2wd;id c3a:6p4u w5xxjkd+ It is observed to have a p w+x udpd3w62;:dxd akw4i5jceriod of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, s94wdkfx q4tnd8b-- u 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 planet with aalnru 08:oc ,i 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 ocy fq)5aov 5e1rbits. 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 m)o qyv5a1ec f5oon B to complete an orbit?

  The planet Jupiter i:w+64p 5 egcqthk r1yqs $7.78 \times 10^{11} \; m$ 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 averay )vopp t) cegyh+x36:ge distance from Jupiter to the Sun? (The distance from the Earth toyp :po)x3)hgtv +c6ey the Sun is $1.5 \times 10^{11} \; m$.)