Is it possible for an object moving with a constant v ;4r, 4ivqoec83j iitspeed to accelerate? Explaici;4vj vq, rto3ii84en.

  Consider a particle moving witho,r ck;hhbt/i) e0w3z 1;rqg w constant speed such that its acceleration of constant magnitudihw3e;h c)0rro,1b /kqztg w;e is always perpendicular to its velocity.

  An object moves in a circular path at a constant +8d;v/)em+xo pc*p m7 qqd4nx as wur7speed. Compare the direction of the object's velocity and acceleration vectors.amq+ *ux778do+)pp /drmnwecv4qs x;

  When an object experienc6o wtrhk ob3*x-vk+3tbh .)s ies uniform circular motion, the direction of the accelerat. hkwk+3oshtbr3 ob)xvit6 -*ion is

  Consider a particle moving with constant speed such thwo1r5;kzg6tp at its acceleration of constant magnitude is apokzt gr6;1w5 lways perpendicular to its velocity.

  What type of acceleration does an object ba(t6dbklbv9 )8m kaq: kp 2 eu86-fjhmoving with constant speed in a circular pev qkbjabm(ku)8k :6bt fd6 l9h -a82path experience?

  What force is needed to make2;z12.6eyva k rkgnxm an object move in a circle?

  When an object experiences uniformro2 qu sa4xan7.t x.2tcbk/f + circular motion, the direction of the net force o2 /bcq7n.+ .xsxkraf2a u4tt is

  A roller coaster car is on a track tha+c1;.uw8gkl jeuvpb7 t forms 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 v luu.pbe ;wkj+v gc718alue for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track thlx*8 b(d5grv eat 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 r8egl xb*d5 (vthe loop, what is the minimum value for its speed at that point?

  A pilot executes a verticalj)n nm0 hjq1b6 dive then follows a semi-circular arc until it is going straight up. Just as the p nqn6jj1bm 0)hlane is 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 of nks.zlzr 1 :2uradius $r$ 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 constant7t2bpc+2wr8ui*d ng t) gfw.x 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 thg 2tn .cfdw*+78r)ip g u2txwbe curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goet h0r2y c6yp a)yhn.)es around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared tonh)60yyct)2he pay .r the first?

  A car of mass m goes around a banked curve of radiuoed1 gz,ff 8y0o2cg6lxk02hh s 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 in magnie fy10 og82 l2x,od0ckgfz6hhtude to

  Two horizontal curves on a bobzl y7y+k)un :.ho82sbf w+;jx+aui pfsled run are banked at the same angle, but one has twice the radius of the other. Tkah2w:nu + u8jlyy f+ )+x7ifob;z.pshe 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 t l p4c-rakwv)-ea+0g track is not constant, but increases upward from the horizclg0vw-epr)a +t-a4k ontal. Coming around a turn, the bobsled 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 tk; urqee9;n( bo have both centripetal and taq ;(neueb;rk9ngential acceleration?

  The gravitational force b wzbw+s11fyvtax*gnf ;.-d i5etween two objects is proportional to

  The gravitational foll :-fq*: td)azoyx1 mrce between two objects is inversely proportional to

  Two objects attract each other grak q+.j6/uf3foc( vizuvitationally. If the distance between their centers is cut in half,/ uofuj.fiv3c z6q(k + the gravitational force

  Two objects, with macc.xc 5jk6kc8p/jp(:b-yiq y sses $m_{1}$ 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 jv(9o) zvh eic)8 g,yzu8 l6ul$m_{1}$ 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 oziln2 b, l3t:b ojxn4+f universal gravitation.

  Compared to its mass on the Earth, the mass of an objputv6w ; 7zqf3bhav kp*6i;1 gny 6pa;ect on the Moon is

  The acceleration of gravity on ;s,i+r;iw /kg 8lgbeaidt,n7 7m uy 1sthe Moon is one-sixth what it is on Earth. An object of ; m ag8b esukwi1rg7d i,,7 /li+;yntsmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the r+jgf7lo u.y :d abza6)ocket's weight

  A spaceship is traveling tob pvlb,01q *vy the Moon. At what point is it beyond the pull of Earth's gravi,b*b1vl0yqp vty?

  Suppose a satellite were orbiting the Earth just above the surfa aw0w4u*:6merxch cgk/ y .te//* zffmce. What is its centripecfxyu*/hg /.mekw 0ec t:ma4f wzr6/*tal acceleration?

  A hypothetical planet has a mass of half that of the Earth g:w f yw( 8*vpy( ep,nd w56zigcqn1k6and a radius of twice that of the Earth. What is the acceleration due to gravity on the p( fw(z1e n8dg, w56 w* kpciq6yvnpgy:lanet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixtna43u(a( jodg h what 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 Earth'sa(j4dn(3 ugo a?

  Two planets have the same szh oc;/luc t: ;b2l7cfurface gravity, but planet B has twice the radius of planet A.;bz:;fcc2 hco l/7tul If planet A has mass m, what is the mass of planet B?

  Two planets have theu*f k 1cf g4wt8k9d;uh same surface gravity, but planet B has twice the mass of planetw8 94k*uc tuk;hdf gf1 A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a ci raremdfeg-x; ,oh .x6o (,mq).beri /rcular orbit (radius r) about a spherical planet (mass M). Which expression gives this satrmob.r-r xefqh(de;g,xim )a/e .o6, ellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. Cco +7k/ 5znellompare the tel5kn 7lz+o /cwo satellite's speeds.

  A person is standing on a scale z--k2-ix9hl ry* esx9 x pze4t*c1bzqin an elevator accelerating downward. Compare the reading on the scale to the person'sks- *qzeb 2*ri-y- hxxt4epc9 1 z9lxz true weight.

  Who was the first person to realize that the planets move in ellit3n)s)(3du9 oatw-xk3pcvz b+ n2s0;v vijupptical paths around the Sun?n +)3 pbxduvv (-3t ivtou3cs92zn jas0)wpk;

  The speed of Halley's Comet, while traveling in its elliptical orbit aehy)q4g4b l-sxd-b: qround the :q-bbdh-s4gq) 4x lye Sun,

  Let the average orbital r/nbk,ayh6rgs w1byv. iy k.6-adius of a planet be R. Let the orbital period be T. What quantity is constant for all planets orbiting the Sh- y r6a .y,k6gbbi/ns.w1yvkun?

  A planet is discovered to orbit around a star ij n(wua+ 3jenp-e .-stn 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 revolution of that new planet be, compared to the Eartht.+w3uep(n--jj ane s's orbital period?

  The average distance from the Earth to the Sun is definezhb t8)9x 6kbmd as one "astronomical unit" (AU). An asteroid or 69zkx8m)hbtbbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.kinqzv;+ p4i:7 )p iud

  List the four fundamental fo sw9;fwmq-6surces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of (wk )nvb)d 9/neco6y v8*hjraradius 150 m. What is the acceleration o vev(nwh)9 ad okcb6nj y8/)r*f the object?

  The maximum speed around a level cur (i5 *d)),l:vcku6 ski1yl n/slwlsv eve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.cu 1 ed ,wli:l)s)vs5k lvk/(s6*yl in)

  What is the centripetal acceleration of a point on the perimeter of a bicycle w jox m5n+m-s gx;a,y8fheel 5xa -jxs n8m;gfm,yo+ of diameter 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. goo*)ek.c2+t dacv)w 200 m from the axis. What is the centripevgto .aow*)2+)e ckcdtal acceleration?

  How many revolutions per minute must a circular, rotating space station of radiu+)pnehe ry xv j ;xdf;wxsw*x(b g:.54s 1000 m rotate to produce an artificial gravi ;.w nvs*4we fx5dy +xx:)pxjher(b;gty of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 9 v9cupldua qof/4b. :kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal forc p.baqulo9cu9 f d:/v4e on the motorcycle?

  A 0.50-kg mass is attached to tx;h 6m t0ubl6 5judw5she end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maxi6 wl65h ;jduu5bxmts0 mum 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 whvrz:xq6/m)t u+ *hf zdirled 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 spe6zrx/*t)vmuzf q:+ hded at this point is given by

  A stone, of mass m, is attached to t8jh637jt.geq2e ux9- c ygbckzn7lr 5 sv./ ea strong string and whirled in a vertical circle of radius r. At the ex8y72gc gtl/qj.u6vjr-e 7 eez .5b3c tnhx9k sact 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,r3npc42 z vvhv,q r(s m/s experiences an acceleration of 4g when pulling out of the dive. What is the h ,(3cszqnv2vvr,p 4r 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 le,gy)fxl4pec,. ec/e oop is beneath him) of radius 3200 m. At thep .f,/e)elc yec4x g,e 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 pilot can stand is about seven times his wes) k-:yjdo3e:x rx) l 60qjombight. What is the minimum radius of curvature :xs6 ):m brdx oql-e)0jyjok3 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 cu wjxwi89,+ cgybk-ea/rve with the tires on the verge of slipping. How fast can this car round a segay c,+xw8 /9wi- jbkecond 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 0wky: u ;,.oociy 46zpx.gwcjflat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by fr:j g0,.z k.4ucwpow6ix yc;oy iction 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 mf7kw,p 3xom,b6pr/ p jx*lyr0a3 hgt5ust be the minimum coefficient of friction between the tires and the ba ,fy*wlp6 o 5 r/xg03tkphx3rj m7,proad for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coeffipui i//vyoc/8 ;8ola kcient of friction between the tires and the u o8/ipv/ oi;l8/ acykroad is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is r5vx kxo3hvqtzmp,*y69eq-+ 5 pk qcb(jbj q 5(equired for an Olympic bobsled to negotiate a 100-m rq 3my*pq (96 5vqz5bvbp(xjtxo+5c,-kqekjhadius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ru cjiq-2* favtsg 29l+un 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 .dq f67uo4k oqof radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at agr.0qb *7wj d- ch2sji.k, lj$45^{\circ}$. 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 *3p0s u8 l w2i+pixsufa string is revolving uniformly in a horizontal circle o 3uu0xlii s2sw8p+ f*pf 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 inri )ti);kj4s n the pit area, a race car accelerates at a uniform rate to a spkt;)sj4 rn)i ieed of 45 m/s in 15 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 of a proton okx*k:piw tu 1d :8ljhw y07u)balt, c;f 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 per+qj1pippgqu0 * s96nuson standing on the Earth, due to the Moon? The mass of the qpu6j+9* 1pngusqip 0 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 mw8 nukfr6u,spe6 )i1lasses is F. If the masses are moved to half of their initial distance 8wsiuf k1nl ,6r)pu6e, what is the gravitational attractive force?

  For a spacecraft going from the Earth tow5rdb/ya b69t q5 ipk6qard the Sun, at what distance from the Earth wilpai6bqdb6yr5 9 t5k/q l 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 Moon isf s-hppa21bgav :br1+ $7.4 \times 10^{22} \; kg$ 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 for0z 7erlp,y j8a04uadx a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her aa807d yulajpz ,r0x4e cceleration due to gravity?

  The radius of the Eaqotlfao2 (;x v/:i xx,rth is R. At what distance above the Earth's surface will the acceleration of gtq ox/2ixaf ;: xvo(l,ravity be $4.9 \; m/s^2$?

  A satellite encircles Mars .hvvhd :eu75t at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gra. hve57u :tvdhvity 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 accelerati9(gsg ;fa;a3khdj j)opx6l j1+ kp4ulon of gravity isg3 h(; pl9; 4k6gjl pxakadjso1j)+fu $32 \; m/s^2$. 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. Ther ;v8gs5qfxazp2lvk80u h2a . Earth has radius r. If the obu vv25f. a0h xps8l82 kzag;qrject is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does 7 rj) f(5aoz,je9cpe xthe weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Ear )p fe9(a7 5cxoj,zjreth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satelli p da0lm:/,ehfbj0pc. te of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weig:m00 ,dcfj.pa l/b ehpht?

  A spherically symmetric planet has four times the Earth's mass and twice iqlxf1 ;(.zov gts radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how qzg ov1xf (.l;much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on -avd6a4 t)g18rx woawr) q3an the same line, with the Earth between th6txa8oar) an1r qdga4w3-v w) e 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 trans 7z ncjj w7ju-7trp(-kported 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 orbit about the Earth (i.e.,hzix/1 14/fts cgl5zzq+p yq* it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth h/1slptzz1qg+i/5xycq z f* 4is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., y7cc9o*g/igl-f 8qpp*3v f ai it just skims the surface of the Earth). How long does it take to make one revolution7 p-ifig8gcaq oc9*/*y fplv3 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 surface of 9fbff.5*e *af 3mgsslthe Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Eart.mbf93*e fs f afg*sl5h is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupi0yq)xov9 fz)k*vypwz)cx ;e 4ter, 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 Jugd q/r o81mp2tv.x5bxjh8v1 ypiter 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 nearb1;ct/vcottkh(m 3ffu -*-p tly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A bt1*3ft/ (-c fvm;pc otk-th utakes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ic29 dfa7 zu *td ;.iqijp4)tsds $7.78 \times 10^{11} \; m$ 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 Sunr6pvjz5ekqyx9v*z 7:/ k1hofya ao:3x 4h :yy once. What is the average distance from Jupiter to the Sun? (The oz:r *x o/y9ae:7 kh 6vay5 x3kyyfzpj :14hqvdistance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)