Is it possible for an object moving with a constant speed to accelerate? Explaia8x3m7o* ;uc+f xtc;z pxg/p(; kdnhkd ; x*o/utk;fmk zncpx7c8pg+x(h;3an.

  Consider a particle moving with constant speed such that its acce+m8wns k1y*rfleration of constant magnitude is always perpendicular to its velocm *nrks1+wf8yity.

  An object moves in a circular path at aci ,0h wk)qa7y constant speed. Compare the direction of the object's velocity and a0 )kihc7y aqw,cceleration vectors.

  When an object experiences uniform circular motion, the direction of/hrr8 wz,t buyhy5t5+l f9mn , the accelef9rmbth,n/zyy+ twhl 85, 5ruration is

  Consider a particle moving with constj00 x doi5ybz f*f,+nyant speed such that its acceleration of constant magnitude is always perpendicular tny 0bz5,od+jxfi f* 0yo its velocity.

  What type of acceleration does an object moving with constant speed in a cirgj+6,exqx qibo ev2 le 9y82+y6(iyap cular path exp 86iy e aeq2bve+ix2y9l,+(ygx6qj op erience?

  What force is needed to make an4z7j:hj: qvgi-n.hn 2 y pfjg1 object move in a circle?

  When an object experiences unifgg z v79o.k:rdorm circular motion, the direction of the net force ird.g:z o 7vkg9s

  A roller coaster car is on a track that forms a circular 8/kcu gy-g9qm loop in the vertical plane. If the car is to just maintain contact with track at the top ofck-9u gm/qg 8y the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that )0l so.h/x/h ot o+nc-i/a vksforms 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 that pon+-hxai.0sl/o/s och/ v) tk oint?

  A pilot executes a vertical dive then follows a6f;c gep l;(uyeyx(i9 semi-circular arc until it is going straight up. Just as the plane isile6exyc f ;yg(p( u9; 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 ow pq o6//j2fpjf 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 at a constant speed/.j udb nu)+zd v. Then it goes around the same curve at half of the orizud b/)+n duj.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 curve of radius r at aw9hrf+nn7 n3 u constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force onwf u7r3 n+9hnn 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 yj3.bwont1 ,jv. If the road is frictionless due to ice, the car ca13. j yojbn,twn still negotiate the curve if 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 kk t,g amw yi8mhv0lkw*mg6isu 88s8)z( 00crare 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)sgu8m,) i(gr000*v mka 8w68 t hsyczi8kklmw for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the u)ggl ,61;ci d u m5zy+7ugxriOlympic 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 cominugd z6 li;xug1i5y urc)7g,m+g out of the turn. Why do they do this?

  Is it possible for an o25bgh k qj*n3qbject moving around a circular path to have both centripetal and tangential acbqngj2 qh 35k*celeration?

  The gravitational force between two objects is proportuiq8*yp efm 2;cmj8s7 ional to

  The gravitational force between two objects is inversely proportionacnazc (s8zlho,5z :5ol to

  Two objects attract each other gravitationally. If the distance betwee7miln -0v5x+djli-x3ijts)y7av: bl n their ceix+y37jb 7 n:0-dl iil)a5vjsml x-tvnters is cut in half, the gravitational force

  Two objects, with masyfvq t3t1 78h),rnl:+nsds knses $m_{1}$ 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 mass ja:qgn6f+6:amxs-w9pq cdl) es $m_{1}$ 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 gravi( o h nx:(4htj.egn+tctation.

  Compared to its mass on the Earth, the mass of an objectxc(gp8r iq3ouo e0sev*o2((nzsm:o 7 on the Moon is

  The acceleration of gravity on the Moon is one-sixth w bjdzums *z()jwm;x2y8 ifk,6hat it is on Earth. An ob zk82wif ( ms,ud;myxzb* 6jj)ject of 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 we1aie1 s(4ajjx1y hm;kun7j ve; u .e7light

  A spaceship is traveling toff s(7dc/w/ cz the Moon. At what point is it beyond the pull of Earth'sz(/ w/cdc7sf f gravity?

  Suppose a satellite were orbiting the sl7hxi5 ;y*uf6v1hkcEarth just above the surface. What is its centripetal ac; hyv l u7k1cfi5h*6xsceleration?

  A hypothetical planet has a mass of half that of the Ear 7yww:b9qz ln 70fv)gith and a radius of twice that of the Earth. What is the accelbfyn iqv)w07:7 l9 gzweration 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 tnoikdb3m)x-f8 jphhaev68v907: w i is one-sixth what it is on Earth. The radius of t tm8d hp)x i 9kw7n-o8bjv fv:3iaeh60he Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surfaceotd;w-4t3ioqy mu a.ix8 z,* b gravity, but planet B has twice the radius of planet A. If planet A has mass m, yowu ,8 3d4izo b*i.tq;xa-mtwhat is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice tx* x:tq cp d+1en2f)qepls2x2he mass of planet A. If planet A has radius r, what is tpcq e2ne*2+qt )x1 :xpsd2 lfxhe radius of planet B?

  Consider a small satellitecpc :)o7gm8n8tr ,mwz moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression grwz8g: oc8cn7p)mt m,ives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. x0 6c10txit)vtbdlfuv7 r8w.o2jgw; Compare the u0iw1xj8t ovg0wc.v; lf7d 6)r ttb2xtwo satellite's speeds.

  A person is standing on a scale in c5zp s1p p.uq 3x*c1ktuwbu3 3an elevator accelerating downward. Compare the reading on the scale to the person's true wecb w1pu*tp3s33k xqp1uuz. 5cight.

  Who was the first person to realize that the pk+rhu)hav7o2x. f5yk wy:5:f tz 0vvmlanets move in elliptical paths around the Sun?kf m7:rhuz )5vo0ayktx wh5 v.y2:vf+

  The speed of Halley's Comet, while traveling in its elliptical orbi 054jqtprrz o+.v9biut around the Sun0.o 49+tzb ijprqurv 5,

  Let the average orbital radius of a planet be R. Let the orbital periou,oo 23kj8sgjd be T. What quantity is constant for all planets orbitingus ok3 ,gj2o8j the Sun?

  A planet is discovered to orbit around a star o/yzj1ctid( r. 6qd9xbl *om -r9gx b*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 revolrcg-61*t.(objdz/ilm9 boy dr q 9xx* ution 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 "astronomicy8-ztvhe - 9jaal unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance fro9eya 8-j-zt vhm the Sun?

State Kepler's laws.i,/ xgm,fvnwyey bpm5 1 3jp(3

  List the four fundamenta2myo.xsvtpl b s8-q2mm 1+(x/m*uqa xl forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiu44 3z-br9g-lxc qrodf s 15fg4rob-cldrx 9-q34 z 0 m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.079;y/up kiu ;cxcx rg5xdaw53 km/h. What is the maximum speed around a curve with twice the 5 xp /;cxkx3uyrac 9;gu wd5i7radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter odv)r :)vb mg7ia,dt4wp ccop 7jsj/72f a bicycle wheel of diameter 70 cm when t d,c:7 jp)4br gdwp2/m7o7)s vitjvache bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is loc( v oar/idx:g:k.oy) pated 0.200 m from the axis. What is the centripetal acceleratio/r (adyg. povk:: x)ion?

  How many revolutions per minute must a circular, rotating space statigd r5 88l)fypy /f5qalon of radius 1000 m y58p)ar l5y/g qf8fdlrotate 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 rqxf)k9xe qqjr62id06 0 vgnt t+0pgx/adius turn at 96.5 km/h. What is the centripetal j6xxgkn0 x+6ti)pqte0v fgqr /d0 q92 force on the motorcycle?

  A 0.50-kg mass is attached lim r iud-+:m6to 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 withstand is 350 N. What is the maximum speed of the mass if the string is id:+r-lium6 m not to break?

  A stone, of mass m, is attached to a strong strink v )d :lvj1rbkzv5mwg 2.;4otg and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 4jomrk v b gd;1.w2z)t:v5lvktimes the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong strypb 6( io j;i93xdmx8ag 0id7ling and whirled in a vertical circle of rpg6dm7o x8al9yd x ;3ii 0jib(adius 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 is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when tg,ucff)8l y :oji8-rpulling out of the dive. What is tictgf o8:ljuy8f- )r,he radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical lo( wm31ak nj9zvop (in which the center of the loop is beneath him) of radius 3200 m. At the top ( a1jknwvm93zof 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 tim t7::(7uxbp, n,pnxlbpzu8v l es his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling pb,up x8tx:(n7:bl,ul7 z n vpout of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius rin-7(0vsxsv-si* m w18nj* fbta9le horizontal curve with the tires on the verge of slipping. How fast can thij0slm(*a sv*f-xi91bvr n e7wst n8-is 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 s bzoduj/: w/ , lmja.09pocdyhk9n u2*peed of 20 m/s. The centripet9 :ou ykwj./dhz*pum/a,0jolbdc2 n9al 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 19*s */)jnha dc xwmlj)gwj, eradius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction betwe ge)1/nlj d*j)hx*wcm a,w9 sjen 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 k 2mz ;jmbh4we mg:;v5coefficient of friction between the tires and the road is 0.40. What is thjvz2g5;m:mhk4;m ebw 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 gzb4znr o9m5j3mpu-2 negotiate a 100-m radius turn at 35 m/s without skidding? (Ign 9mb45m guz32 ponrjz-ore friction.)

  A horizontal curve on a kk-50rhoc-kap ohd-f7u .q m ,bobsled 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 ans 3-y7d.tm (cz .xtcpxgle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m1 uw +) 2qh53jqfj0obyb njjc8 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 un ne jp)+w- i6sc/mm)btiformly in a horizontal circle of rasji)me/pt 6cw- bmn+)dius 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 ac4nfl.) qw*;x kpkhiq, z))ufvcelerates 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 in fq,kqnxuf.4 kv*l zh)iw )p);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 protoxfc2gxs * 9.ob aj4zc2n 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+gmd4rph+bc1;l)d sf the Moon? The fc+r+dm bdl)1 ;4pg hsmass 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 m9x;(6 tgdk ykz8pj yr+asses is F. If the masses are moved to half of their initial distance, what isygk t y;69kpjz8+xdr( the gravitational attractive force?

  For a spacecraft goi /47 zu hrochf5avabt523p-xlys*r 7 png from the Earth toward the Sun, at what distance from the E723 prr5of y*/7shhtl- ax 5c4bzpuvaarth will 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 Moonay,c1 4pvqyw/ 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" at a distance above the Eart4kmyv*w cm.:xj 9nca2h equal to the radius of the Earth. What is her y:2 xm.mc ncv4w*akj9acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface wyar5.+ez+m hlq0 n:g v4a*d pxill the acceleration of gravity :+hdzn 4m x0rq*5leay+ga v.pbe $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 timevh.cf( s 4r.lu7y3do is the radio.us 3d hl .(yicr74vfus 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 fxzm)/k;*z 7bln ihrh /rom some planet's center, the acceleration of gravity i*i /7nhzbkz/; lxm )rhs $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on 5kc:*hpiuiq6epq /n 1 dvg88u the surface of the Earth. The Earth has radius r. If the object is raised to a heigp5cue 6p/i8qhiun gv1dk* q8:ht of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg *vk u)ldoy(b2person change when he goes from sea level to an altitude of 5000 m? (The mean radiuydvo (2b) ku*ls of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r aboveuv2;bn (bqjvlu oq cc84m2b( 4 the Earth's surface. What 8c(j4;o(ubuv 24lqqc nmvb b 2is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass ai* zjs s8u9jgf n(qg67vje*(und twice its radius. If a jar of peanut butter weighs 12 N on the surface of qs7g e6i9 v8fnzj j**j( suug(the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun a,n 51yy v 5xixd-(vng.xj5o3+k ckmlyll lie on the same line, with the Earth between thecklgi 5x.5o ( vm5-knyvx3yj+nx d y,1 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 tsyb9(l4c5y keo 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 circulaqidafft s:b my3213h 2rl1.v dr orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (Tls afm3bd21 1hqvd .ty32 fri:he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth zl;+ bk;xpunri3 x2 2x4apt m9(i.e., it just skims the surface of the Earth). How long does it take to puxz4bp+x2a29x n3;;mitlr k make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 go ungc5mi +b t.6)(c(e/ua nskm above the surface of the Earth. It is observed to have a period of 89 a)gu5umc/ns(t g+ceonb6 . i( 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, has an orbital di:cslcclp y(j 0dx2k6u3 ej3) yameter 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 radius ofwm. xf9ip:-1 hnq ur6t $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in :w8do;6eby(pc9 zyaf0l -ca nnearly circular orbits. Moon A has orbital radius r, yecdp n6w(y-9:b;0caz8fa loand 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)1f*oma w pv9ieisk3 li, +4mws $7.78 \times 10^{11} \; m$ 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 onceb6 :b.kpst* sk. What is the average distance frk6sb:t *pb.k som Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)