Is it possible for an object moving with a .zv(a ; gwjtr rtl,ud*w8vz:6 constant speed to accelerate? Explai gu dtvl w*.trjw(8:z;v,a6zrn.

  Consider a particle moving with constant speed such that its acceleration ops 4- per: nmu7q7j,4pkr+u pdf constk,:7q4p7rm rduus4njp- ep +pant magnitude is always perpendicular to its velocity.

  An object moves in a circu6(s em lt.kgy:lar path at a constant speed. Compare the direction of the object's velocity and acceleration (lk6ye.smt :gvectors.

  When an object experiences uniform circular motion, the direction of the accez 68d5p:)qv+lqyn ds+ge8 q txler+ xyzd:en5tvdq8q6slg +qp8) ation is

  Consider a particle moving with constant speed such tha6diuiu 6n,jwt;,5 uhbt its acceleration of constant magnitude is always perpendicular to its velocit ,idju,b5hw; nu6it6uy.

  What type of acceleration do/ndj6 nd90dzjog wr-9 es an object moving with constant speed in a circular pathon/9j 9dnzrjg6w- 0dd experience?

  What force is needed to make an objec1 vy-fj3+f 7bjejlu0n t move in a circle?

  When an object experiences uniform circular motion, the di ep*7ynxd)mr 1blg0 )2r*hdkwrection of the net force ix )d epmb02r)1d *hygn *7rlwks

  A roller coaster car is on a track that forms a circular loop in:5w8y2jf e;2tuafxm p the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum f825jam;fp ty2xe:uw value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that65uhw r*zqh4t47utdx5 0 uqeu*9bx ah forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain conta549 qb ur70uettha*u 6hqu5h*wxzx4 dct with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc untuo 5jb)u o7x/gu :i 0dbc5q7fi/wbl:ail it is going straight up. Just as the plane is at its lowest point, the force oub:a5jx7oc b )7u/ ilfiu0d ogq:5b/wn 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 sax/s,bz2qn 6 dv 54jdmwz;0sradius $r$ 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 it hx*al b, zklf1aes )u3qv9lp* /z ve(.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 sele/*9zv1(.be* p)zaf,uas3ll vhkx qcond time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. ez6ni63th+ 8d4*j-elhcwwid uj/ymt *mp 4e6 Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as cde*jtm 4z6*jnilte8h ww u y mh 43-+ed/6ip6it goes around the second curve, compared to the first?

  A car of mass m goes around a +u3jtbq z, u725drkrkbanked 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 is equal 25 ,dzjr urqk3kub 7+tin magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but o0w va,od t2 kezf0+ 8eciw9ia2ne has twice the radius of the o0 ie 2tzo,f aavww89e2ki0dc+ther. The safe speed (no friction needed to stay on the run) 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 Olympic bobsled track is not constanan,fomd5) 8* 3u;x1f u)b(mmfw fkms ht, but increases upward from the horizontal. Coming around a turn, the bobsled team will intf8man f)dmm ;wu1sk*ub,mf5 ()h x3o fentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving aroj 08yug,b+j liund a circular path to have both centripetal and tangential accelera+bylu 0gj,ij8tion?

  The gravitational force betweenyxkzkq /so. 0)c-un7vx*hd k- two objects is proportional to

  The gravitational force betw* x50z;/ntiyy5*rhcg qp 1a gseen two objects is inversely proportional to

  Two objects attract each o,b*foaoun :qn7i-z 7j ther gravitationally. If the distance between their centers is cut in half, the gravitational forzqbo7j :,-i o*u7anfnce

  Two objects, with masses .pv-1nhzxm;e1i9 sscs 7wzw . $m_{1}$ 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 masse6skwt7 kff*h. 91lt jhp*km o3s $m_{1}$ 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 unuye : *p:erl efb/2dq5sd(nm+iversal gravitation.

  Compared to its mass on the E;s ) ndz vo)kt21cfs(xarth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Eartq+z0 bxm.(djxh. An obj(mx+ bq0.jdzxect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfay26:c tul+,: ne dmhirce, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the py5 f/2 opbebps99zy.p ull of Earth's gravi 9 9.bpsy/2fppe 5zbyoty?

  Suppose a satellite were orbiting the Earth just abopqh+x 02 yctp.ve the surface. What is its centrip2+xctq.0y ph petal acceleration?

  A hypothetical planet has a mass of haln:9)1cddupqdfn;cy 5 f that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the pl5f qd ;dyd):npuc1n9 canet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. The :,o qrx96vgmaradius of the Moon is one-fourth that of the Earth. What is the Moon's mass comp aq,x:orv6g9mared to the Earth's?

  Two planets have the saym:06 a4j; da e0dlaisme surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mas0aj 6l: 0mdsya 4iade;s of planet B?

  Two planets have the same surface gravity, but planet B has twice the masok+dkc(v-9lw s of planw o-(lvk+ d9kcet 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) abou-umbt. f/wk9l ;uth9w )ssm5ut a spherical planet (mass M). Which explw b.f 95km-t/us huuwt)sm9;ression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite 9xomwru08 ap1B, and rotates in the same orbit. Compare the two satellite's speed8m0xpa 9 rwuo1s.

  A person is standing on a scale in an eb.v4 qr;8eta rlevator accelerating downward. Compare the b q4t8 a.;rrevreading on the scale to the person's true weight.

  Who was the first person to realize thaa54 3zo 5 hae,i gg/tvwf7fbd*t the planets move in elliptical paths aro/3 o,ghf*wfez54aa7tbv dg 5 iund the Sun?

  The speed of Halley's Comet, while traveling in its elli +r95zalw/ )ozokl4 mzptical orbit around the z)lo9ml+w 4/kzar o z5Sun,

  Let the average orbital radius of a planet be R. Let the orbital period be T. jsfr3h b 2l;3)1cnzlkvclhm/k7jt9 - What quantity cl2r-9 1)lf;hk7vzb/nt hl3 3sjjmkcis constant for all planets orbiting the Sun?

  A planet is discovered to orbit around aeqz+d;f rld+5sp- c0 c star in the galaxy Andromeda, with the same orbital diamq- cp5+;z0 d+d srfceleter 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's orbital period?

  The average distance fro6c,bsetyz9lbxh/ b 8.m je+i j4ia0;d m the Earth to the Sun is defined as one "astronomical unit" (AU). An ass b68.;l9+bcta ymi4 ze /ijje0,bdhx teroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. e3)w9-ux e8 vsrdy /7mq6gsxv

  List the four fundameohe*1gyb;k qufp;w x*+4hf e7ntal forces in nature.

  An object moves with a constant speed of 30 ;vgdeb 723oxi uyk0)cm/s on a circular track of radius 150 m. What is the acceleratie3vgkxo ;0diyb cu2 )7on of the object?

  The maximum speed around ark d2eavv 6/x2 level curve is 30.0 km/h. What is the maximum speed ara6xvdk/ re 22vound a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the9 jwi t:89qecr perimeter of a bicycle wheel of diametec:itw89 9jr eqr 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.m ;ym mnz(w-:c,eob8k1)bgu b 200 m from the axis. What is the wm1uc;:bybomge-()8,k n bm z centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of r)f4e00vs b; ma3 cprhoadius 1cva ) shp0m30oerf 4;b000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goe2p8(8ad jtyaz s around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force o z2t(88aydpaj n the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m stdpbyvur.z:bf.ryz ;r;y*/ l +q1 7laxring. The system is whirled in a horizontal circular path. If the maxivbr xd+yyr;z yf l;7b.pra uq.l/1:*zmum 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 attacheds+s0rlx0)dkg to a strong string and whirled in a vertical circle of radius r. At the exact top of the path thek0) xr+lssg0 d 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 strijtyb9 6vd0g2n*;ug g;9 f 4;okpuylj xng 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 weight. The stone's speed at this point is gk nob4f tj9* 9yv;6ul2;g jy;gdx0u pgiven by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out l sh/ d+i, :-fadauh)cof tfds+lh,cida:h) a- u/he dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertic lpyo+gvp d) qzz.qjx:;h(.-eal loop (in which the center of the loop is beneath him) of radiuqg)dv.p.+hy lx(e jp oz:q- z;s 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 pil.fyd+k0/j9kf dkd t8 xs-; *f,s)e+bu qobnxcot can stand is about seven times his weight. What is the minimum radius of curvature that a jet planfxns/ ,dfu)f+qx .y;s - 9 ckjoetdk 8bb*0dk+e's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s roundsjs gr2 /dk) l60p unb sck0p.h(g3gq9j an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of fr)gjdh 6u/2.r 0 kpqgkp( sgj0cls93nbiction 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/i.:by p13i ipnwm) 7j dbjdz31,t *dc1uk4qags. The centripetal force provided bwujn d.:)i11 gyi3tqda *1pji m 3b4p7bdck,z y 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/s. What ao/m6h 8tf( g+uh2fwlmust be the minimum coefficient of friction between the tires and the road for the car to make the turn(6+fugwh /a8l tmh2 fo?

  A car is moving with a consr/;h ovwcsm2g+t 4dr9 tant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve r 4s;2vow9th+gcrd /mif the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsles-erlx2hllea nw9l6)z11 z5id to negotiate a 100-m radius turn at 35 m/s h 5llle1exszz29nri 6aw-)l1 without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run ins5s+ gefj j99s 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 :t7 d/n0nxw u qct6g;hat an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is b -5y x)l9zsxpganked 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 uniformly in a horizontae)gcxf mnpd*u r ,-e+0l circle oer *udncxf0,-e)+gp m f radius 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 accelerates at a unirps o7:ru ev -.0/w:pyktoc)z vhjw -2form rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (onlkoh r7:/ -vzcsv -)puw pt:.rj2oew0yy 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 con *v7b 7m1cq2ebuc o* 9ztu,xhdsists 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 gravitational force on a 70-kg person standing on the Earth, due /, 9m1/nsa:nj vdhwh7 pcy8ji to the Mo:mwn,ays/jn 8 pji/ hvhd79c1on? 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 ma .(/jwg7svjx;9 emqa ;fc:yywsses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive forcew wvyg;fqc 7yjx(a;:9mj/se .?

  For a spacecraft going from the Earth toward the Sun, at wha. rimed hlr4-otxdx7q1q 8vlp0 +.s a6t distance from the Earth will the gravitational forces due toeq osm.v-8tlq 0x 7dpx6 +4lr ihr.1ad 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 ah- ngz phi*m )4um0;c)eq4xuis $7.4 \times 10^{22} \; kg$ 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 q nobyf+*ji;t5cb5y6u )aq) a 1zrhp2"space-walk" at a distance above the Earth equal to the radius of the Earth. What isbh)u *i1+pj55;y aqq2nfoty)b rcz6a her acceleration due to gravity?

  The radius of the Eart gxp 2to24 qdydw39f-ah is R. At what distance above the Earth's surface will the acceleration of gravity a-94tq2 og32fpd ywxdbe $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance (qp57/q 1dbyw u06jzrh9xg3lkb yw- tabove its surface equal to 3 times the radius of Mars. The acceleration of gravity of the swld w9 hpxzy b-1by(/qjg0tu5 kq3 r76atellite, 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 acceleration of gravi/*vhrwrp7(y kh vy-hu5,vw .rty -v, ruwv/hyvh. ryk 7rwp(5h*is $32 \; m/s^2$. 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. w2ni cb co +dxl(l:*z.If the object is raised to a i+2dwx(n *bc. llo:zcheight of 3r above the Earth's surface, what is its weight?

  By how many newtons does th )cv0w5ke4xaa j;l)ur e weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the jwl v5 ra)4;a)kecx u0Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point :99zvf o;oke;y ,badj 3r above the Earth's surface. f;99zbjk;va :yodoe , What is the satellite's weight?

  A spherically symmetric planet has four times the Ezc h5.6,ohbmac 0. :lb/)jtfcah,vkelmv4 .aarth's mass and twice its radius. Ifmak aboehj0 ,c.tbhvmch,a f 4z5/c):l 6. .lv a jar of peanut 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 onwqwpuj 7qs1g- :9 gn wsb;1fx/ the same line, with the Earth between the Moon and the Sun. The Moon has /fw :ngj; sp-9s1wq 7x wb1qgua 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 t5ts. lo8+kbav 4bhc3 sransported 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 orfj*z sgc+jxlv x;l ;* m62xd.pbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellit z+j2l 6g*;l.j cp*fx ;dxsvmxe? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aboutdom4tl 3aq42 n-c gs;x the Earth (i.e., it just skims the surface of the Earth). How long does it take to make onen4s; l4qac oxg3 2-dtm revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 2k*u b2m 7,envl30 km above the surface of the Earth. It is observed to have a peneb7kl *v2mu ,riod 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, has an orbital4jr3ifh8r0 h b on)kzwo672- ch8s kwh 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 Jupo62 g-p:wh7:gl9c +fkbgahx vc9d ) jfiter 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 orbital radiu(sp+ yw(s eq;xxf+k -us r, and moon B has orbiuesw;p x(+-(xk qyfs+tal 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 iflhw+fjzp)(1b y)6ius $7.78 \times 10^{11} \; m$ 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 average0 5l wprrb1:hu distance from Jupiter to the Sun? (The distance from the Earth t0:1p5blwu rhro the Sun is $1.5 \times 10^{11} \; m$.)