Is it possible for an object moving with a constant speed to accelerate? jbnk )qqgbo 9h)(5mg+ Explain.)(nmj khq9 5gbgqob) +

  Consider a particle moving with constant speed such that u-5r qkc2j k:e h8xb/b*x3 4lil1aay kt0r.brits acceleration of constant magnitude is always perpendicular to its velocity.kxeyk rqrl 3a14jk5b -baxu*2cihb lr:.0t8/

  An object moves in a circular pa:-gksv( (rk8uf x7otqth at a constant speed. Compare the direction of :(fs7r gvtqku (x-8okthe object's velocity and acceleration vectors.

  When an object experience *xro7zlo1-.;9l y/ hl akrahcr6 rf+m+1pq ius uniform circular motion, the direction of the acceleratiq9huo h*ir7r+ /+oz ;xyap lc1-ml fkl r1.6raon is

  Consider a particle moving with cotkq yi3.:j;yxm1yi8v*qy vg. nstant speed such that its acceleration of constant magnitude is always perp8;ygv1miy.q x.i3t : y vy*jqkendicular to its velocity.

  What type of acceleration does an object moving why d.cy ka9o67syt w;3ith constant speed in a circular cdathw7y s.9o ky3 y6;path experience?

  What force is needed to makw +km4h-j:mo 9 w6kem(ygta1l n8.h9ns ob-cpe an object move in a circle?

  When an object experiences uniform circular motion, the direction of thenr*o,st 9j6e j net force j,j n6os *t9reis

  A roller coaster car is on a track that5r m c2:)x5jrgz.7wls5 teq bx 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 value for its centripetal acceleration at this p:r55 xtxcegm75s)l w z2rj.qboint?

  A roller coaster car (mass = M) is on a track that forms a circular loop c)q+y+ dwzysx1o 16ve(radius = r) in the verticals++y61c vwoyx 1qe)zd 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 point?

  A pilot executes a vertical dive then follows ogu .m.ql:ucth z80k3 a semi-circular arc until it is going straight up. Just as the plane is u3mh0tl k.qgo:.u8 zcat 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 curv.etd evfp x0-t l9*mk0e of 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 v. Then it g9x7h-f )fpds6tkff 8goes 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 secf h96kp8f fxtg7df )-sond time, compared to the first time?

  A car goes around a curve of radius rvtbwb6t44zt 4 at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curvezb46t v t44twb, compared to the first?

  A car of mass m goes around a bankwx37*y;vguxt l4g c,eed curve of radius r with speed v. If the road is frictionless due to ice, the car ca,*xvgx;ywct 4 7gu3le n 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 are banked at the same angle, bu; g* 3ao,f;vpabds 7ly3qw a9;zbcd)ut one has twice the radius of the oub;a ;f z 9agqa dyc,ld*3 ow7)b3vsp;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 Olyms4 a(gh1 cd*sppic 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 coming out of the turn. Why docp1g4d* has(s they do this?

  Is it possible for an hx)fo ,c r.wl(fk60jq object moving around a circular path to have both centripetal h)0kq,.cw ofj (xlr6fand tangential acceleration?

  The gravitational force between tworoj m,xp7if)dx*5nejx17: kiipiqk :349c eh objects is proportional to

  The gravitational force between two ob; jg ut dpuv3.h7m5)rxjects is inversely proportional to

  Two objects attract each othiwu. uc6uj kwwwh2:;/xj3cz jv6tri:4.3 goj er gravitationally. If the distance between their centers is cut:2oj.; wuw vj:xr3kj h. c 3wu/6jiic4uz wg6t in half, the gravitational force

  Two objects, with masse8vr qh;fn-q9 es $m_{1}$ 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 maev:kpv 9- 1hr(9 ediqttmvs, (9flw1tsses $m_{1}$ 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 o:t1z+c /jzm mcji8lidu * 1 xk1za;d,xf universal gravitation.

  Compared to its mass on the Earth, the mas.n ,u;bm(vhlls of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it isnmuzlb( 6h r*eob33h5.x pt)h. hot;o on Earth. An object omnl3. 6t()u. op5to o;e*hx hr3zbhhbf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the xo ulk8g9 0(o+q a ,grvp4jky1Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyooybte5osw.t +b26 jl)nd the pull of Earth's gravi2 es6wlt) y5jbo+obt. ty?

  Suppose a satellite were orbiting xsl9n vnh)jd3*4tqt6 the Earth just above the surface. What is its centripetal accelt4njvl 3td*sqh )nx96eration?

  A hypothetical planet has a mass of half that of the Earth and a;up ogkw wh2*1lhhdqx3ih5m44 )(zep radius of twice that of the Eartz hwmld1(253ikg4p qwhxu 4h p*h)e ;oh. 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 it ism2 x n-pr zuo38+id,wb on Earth. The radius of the Moon is one-fourth that of the Earth. What-rmdx +i p3u8z 2wb,no is the Moon's mass compared to the Earth's?

  Two planets have thewfike,/wiuk.3m 4g ;x same surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of plan,wkfkeig/m x3uw.;4 i et B?

  Two planets have the same surface gravk1vn dyp8u1 jy(-sm 9xity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of planet Bkj9p(dmny-1xyu 8 v s1?

  Consider a small satjx qz:p0 0wah81/: uixuyeuh* ellite moving in a circular orbit (radius r) about a spherical0/y:uez whqjia8xxh:10 p *uu planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orjyq4-r8q :ikq bit. Compare the two satellite's qj4k:8r-qi yqspeeds.

  A person is standing on a scale in an elevator accelerating downwar* 1birocv6mof z*/h6p d. Compare the readinghcrp ifm16zoob/v* 6* on the scale to the person's true weight.

  Who was the first person to realo +/nyvlp7sg dh4 -d3vize that the planets move in elliptical paths aroyd7g+ l o4hdvp3svn/ -und the Sun?

  The speed of Halley's Comet, 3l5ukk iy49lawhile traveling in its elliptical orbit around the u5lik4y9a3l k Sun,

  Let the average orbita/f bfjz fd--) q0j0 1r,kptgiyl radius of a planet be R. Let the orbital period be T. What quantity is constatfiq 0)p1 zk0f-rj/ f-jyb,d gnt for all planets orbiting the Sun?

  A planet is discovered tl4c2wcdflmpy)n l.sz1f*p 5p(lb1 6jo orbit around a star 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 wfc1s.j(2n ll* l c64pp5pm)bfd lw y1zill the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance fromln(em u/ihn 3oi*2 ).r,ahqla the Earth to the Sun is defined as one "astronomical unit" (AU). An asaa u/2inn)rl ,heqmoi. 3(h*lteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.0 c-mwiw m(gjd u+ciw5299yrk

  List the four fundamental forrxm-k t; dlceb-r0d0h 28ma( tces in nature.

  An object moves with a constant speed of 30 m/d.tfjm(mc-n; 0s ;esz s,)va,psbea p 7wla .:s on a circular track of radius 150 m. What is the acceleras a( a vwzf pej,mct:e;7;0.ads-s.)nbmslp,tion of the object?

  The maximum speed around a levvu t8(u llfk0)funb2 9ec3 *xmu)jd (uel curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors reujn vk*2 xbfu)dutulm u(cf8l0e9 3)(main unchanged.)

  What is the centripetal acceleration of a point on the perimf0xct /y3x1p9ctacb px;-k ,g eter of a bicycle wheel of diam;ac3,k c9 -/cxf bt p10xxtypgeter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located hy )h8d2r/ 72zxex nhw0.200 m from the axis. What is the centripeta2wxnd hy) hr287e h/xzl acceleration?

  How many revolutions per minute m d3lj:*qu+l+l f2gt tmust a circular, rotating space station of radius 1000 m rotate to pro*u+m23+:f ld q tlgjtlduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13f*i 9ynejwp3jn6 cbqnu4298 z.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcycle?6 3n qu9w8yc*nbnzfi429je jp

  A 0.50-kg mass is attached to the end of a /6 v h0vflo6: wbrtpo41.0-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 striwhftvl/66 p or4:b ov0ng is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical cir5rn0kr mf- hl9cle of radius r. At the exact top of the path n 9kl-m0hr5frthe 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 stwcw)2+b2 x3qht qn 4doring 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 i2d n3c+wwhob4t q2xq )s given by

  A jet plane flying 600 m/s experiences an age: 3i 9yvjgu uc.vn*(cceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyingujev(ic*:g 3yn 9. ugv?

  A pilot makes an outside vertical loop (in whqgv wpt5z,q k 3kht6,t.l1a2(f4 v jwwich the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing dow6 kt4vjw(1ak2 3.w w,,vl5qpqgt zfh tn on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is ab9i3pe1mw 4vqq)m +jkiout seven times his weight. What is the minimum radius of curvature that a jet planjme41+p iw9)k qqi3vm e'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 the tires onyxu9(-huft((3 o v ;rgumjug ,lk*0h n the verge of sli g(k;vu, jrh y3xl-nt09ufh*(goumu (pping. 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 spee iv ya*/;:dc zaed-q(nd of 20 m/s. The centripe/q( -ad* dicv:;aez nytal 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 ruj/6rva2 2g8pc * kqifadius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and ig2u2kf*6c ajr8vp/qthe road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The con-mzu m tq .59ux*-5rk hj7mmgefficient of friction between the tires and thetkh 7m9mjg5- uz*mmq -u.rxn5 road 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 required2pbgt*rn.va d:an80g for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s wit0. 2rap* dv b:nnagt8ghout skidding? (Ignore friction.)

  A horizontal curve on adevhis f) rabdm2.e1 lv1,y, ) 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 ) twfz36n: igem, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked y)px de2:w kk.jff5*jat $45^{\circ}$. 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 iq *u sx.05jqw+k/jtjon a horizontal circle of radius 0.j +u/x * wsqq5kojt0j.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 rac gyk:pc /wvvl qe*/ 9)xs/;nwxe car accelerates at a uniform rate to a speed of 45 m/s in 15 s, movixwn l/ gy;vv/es w/)pk9cx*:qng 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 o9pafko* pgv ntnp .zyxjbde25,7 1/u,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 person standing on ths l7rjsk8g h xd *p0ty4rt.*z1e Earth, due to thdrl7r .*0* tjy s4zsxgk1p8t he Moon? 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. If the massel /1bmct3 p+fvs are moved to half of their initial distance, what is the gravitationpb t1lc/f m3+val attractive force?

  For a spacecraft going from the Earth toward the Sun, at (z: hfsud ((3grfv fxi3qea6w- 04 eyywhat distance from the Earth will the gravitational forces due to the Sun and rhf((wef-us43 xegif6zda03yqvy(: 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 u89 )ilijo:o6pe uom4 $7.4 \times 10^{22} \; kg$ 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-walpwms;5ov *i 2fk" at a distance above the Earth equal to the radius of the E ;5iwp vo2*sfmarth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earquqm47snr8) xb9 fgo9th's surface will the accelerationxbn8q7 mu rs )g9oq9f4 of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 t or .j+ 9wnti8rm:mh.fn 9bvm6o:x9kg imes the radius of Mars. The acceleration of gr.vm:r6gn nm mf 8tow. hrb9ik:+9j xo9avity 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 ac(qiss8ua*m62r9h yv w celeration of gravity vr9s h(s2i aw6q*8muy 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 radi,s s6+f)bnnb uus r. If the obufs+b n,s6) nbject is 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-kg person chnoz vz97d9zn- ange when he goes from sea level to an altitude of 5000 m? (Thez79nnz -vzo9 d mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. kc 3z6:)xsio,2cl hlt A satellite of mass 100 kg is at a point 3r above the Earth's surface. 26i3c,l)x z sl:koh tcWhat is the satellite's weight?

  A spherically symmetric planet has four times the Ear+vv )c. c.b co)urdo3rth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surfaceo b rcvco))..u3vd +cr of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, andvllxi -* 9vb6/qrvlgz0 e94mg Sun all lie on the same line, with the Earth betwqvgml -xb*9i rle0lvg/z4v69een 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. 0lly3vw6m t 0c
(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 just skims 1tf4 z7/gra9+ a*e eoenurt0y the surface of the za7 erg4fo0 /1ateny+u9t* erEarth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low ci.ymu8h 4cf9kf;a-d harcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does 9hk4f.hamu y-ca; df 8it take to 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 km above the ,6h qg.axa.tci2w ez-,)xqd fi).7 vzfcx /ea surface of the Earth. It is observed to have a period of 89 min. Wf.f .z/cg a6va z.exqe,ih ,aqct)dwi7x x- )2hat 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 o4to*85 +jayj/*wq5v f bg ksgjrbital 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 planetu f:3ipx rd0;a 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 or4cckkn ;sh1tk 1c,a-rbital radius r, and 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 kt-h kn scrc41kca;, 1orbit?

  The planet Jupiter is(nh5*sql kdcwkzg+f (:ehp1 6fhb7* i $7.78 \times 10^{11} \; m$ 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 orbib8/lm yoig2z( t the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the8 2mgiz /ylob( Sun is $1.5 \times 10^{11} \; m$.)