Is it possible for an object moving with a constant speed to accelerate? Ef6*nv 7r5jh eag;a ee/xplainnj 56heer g/vaef;7*a .

  Consider a particle moving with conu*.j*facfu 7n7a o:/ r tc1bqostant speed such that its acceleration of constant magnitude is always perpendicular to iq a1rf*o nc:fub7/u7t *coa.jts velocity.

  An object moves in a circular path at a constant speed. Compare the direct); n+d2ijkdgo*j-8qe 8xd.ybcic gx3ion of the object's velocity and acceleration v8-g*q8ogkjb .nidjd+cye3 id2xx; )cectors.

  When an object experiences uniform circular mwnu afk2m 8 bz-j-,3leq ol34yotion, the direction of the accelerajek l 248-uom a qfb-nl3,3wyztion is

  Consider a particle moving with constant speed such that its ro0uq0vc h2a*uu 0z u,acceleration of constan20ro0uzq c,h uu0ua v*t magnitude is always perpendicular to its velocity.

  What type of acceleration does an object mo q)ulr 6w-70;et-d7 usfsrfnh+/y brk uo/)ssving with constant speed in a circular 6eq-r frs+7u0srwk//l)yu)tu d7-b ;ohfsnspath experience?

  What force is needed to make an object move in +/vevi0dxw1 b a circle?

  When an object experiences uniform circular motion, qi.;k h4ez,a pthe direction of the net force iq,hi4p a;z .eks

  A roller coaster car is on a track that forms a circular loop in the verticr 9z7-ffj0gs pal plajp9 z7g-r 0ffsne. 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 point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (radiulb vjpu;(57 mbs = 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 poin v;jb pl57b(umt?

  A pilot executes a vertical dive then follows a semi-circular arc untilecx8p b9ei9mb 1k4:p p it is going straight up. Jus1ie4 8b :b9k pc9eppmxt as the plane 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 sxj127oej5zm u6 wgxgs.k.a4f3 c *rgof 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 con0w2vm//ebj po stant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car b /o/0ejmvwp2 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. Then it gfhr**5z)n ew noes around a curve of radius 2r at speed 2v.ewn*n* rh)f 5z What is the centripetal force on 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 :sd8v e*nh2:hmbn5 .bu na/oh with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the:embha/u5h8s*h2b: n nvod .n normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a ,( ssdte(5+if(avqk z- y xhl4bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay +z(iys4vtfq (edakxlh s5, (-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 constant, but inw 9aq8n,0xxgk m)j un8creases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn8xakwxg n)u ,98nj 0qm. Why do they do this?

  Is it possible for an object moving around:-qwkdc,zdp9 a circular path to have both centripetal and tangential ac-d 9cwkq:z pd,celeration?

  The gravitational force between two objeuc(;y0abhfxn l90g;j cts is proportional to

  The gravitational force between two objects is inversely o9kxgz0k., nwaaf nro,bd:/1proportional to

  Two objects attract each other gravitationally. If b(p 2i j-,ce6zv9fk,0ulvjyhthe distance between their centers is cut in half, the gravitation,9z,je k6lu c2f(-vyhvipj0 bal force

  Two objects, with ma ,ui9hen8p c4nsses $m_{1}$ 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 ma(r ;a ia4t x0: l1oebaw4hza+jsses $m_{1}$ 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 0utgn6 8u1eg pdjh:pf a (0 4dbfb42bzuniversal gravitation.

  Compared to its mass on the Earth, the ma2uhrd2 uc,09*.il hk :cznp+nxv bp *r(q8ldxss of an object on the Moon is

  The acceleration of gravity on the y-+ ) xmlirfy; af9-nsMoon is one-sixth what it is on Earth. An objefm -i y+)y-xsrnlaf9;ct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, tjrj ,g6.cqoh)q1box 9he rocket's weight

  A spaceship is traveling to the Moon. At what point is0 krqi cpk4:+bk,ut8x it beyond the pull of Eart+ q4, ri8xkk:pkcu tb0h's gravity?

  Suppose a satellite were orbiting the Earth just abozmvm. b mxm.tko0m36.0(4 b/up eyvanve the surface. What is its centripeta a/emv x.m4 mt vu0p.b0o.mb 3zn(ky6ml acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twicx/tnz pr;d ;z2e that of the Earth. What is the acceleration due to gravity on the planet in terms of g, ttr/p;x zz;2 dnhe acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it ig- g..fdat yr2s on Earth. The radius of the Moon gtdg..rfay- 2 is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the sada3 vl w*aqt :(c/b- c1lqki:zme surface gravity, but planet B has twice the radius of planet A. If planet A has massd1/l-kz t ::c3qv bw*q alci(a m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of p)6 ybiu *s9biuwp7.7rj9x6c t* vswdilanet A. If planet A has radius r, what is the r 7jw7bidruipcu 6) y*t *6. sbs9xwv9iadius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about aeg *y mu0x5d 19cm0ooi spherical planet (mass M)mou5g1di09 mx0ec* yo. Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of s49fe pf2h mb6uatellite B, and rotates in the same orbit. Compare the two satellite's sph fuefp9m4b26eeds.

  A person is standing on a scale in a*m ua+:k .3 j2w:qzdni*rkabw n elevator accelerating downward. Compare the reading onaq:bu:+ *3r.waw jm2 *nizk kd the scale to the person's true weight.

  Who was the first person to realize that 3vs.rw eqhk4+the planets move in elliptical paths around trk4. sq+e3 hwvhe Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbi(;2;4hrx0x shyf4 xd gap5kkxt around the Sung(5x xhdfx;x 0h 4kp;k 24arsy,

  Let the average orbital ra.kzc., fv8 -iv/pqlj cdius of a planet be R. Let the orbital period be T. What quantity is constant for all planets orbiting /8vzf. -.cjic,q lvpkthe Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with w, *1uli kbs/jufw ))fh 9v5ntthe same ob unf1/ut59 wi kl*w) ,sfjh)vrbital 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 Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomical b,/va 9tb 4(fqo(2t-ue6nsqvq qc 0rbunit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's averagserq( 06c/vq,2qv tbua 9tnqbb4f -(oe distance from the Sun?

State Kepler's laws.dei8 ait+wsh b )/k7f:

  List the four fundamental forces iaod 2pj5w0ms4 n nature.

  An object moves with a co o;a kqk,1o.pcnstant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration qok. ,p;1kcoa of the object?

  The maximum speed around a level curve is 30.0 km/h. Whhy7pd3 j k)wr7at is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchr3d yw)p77 kjhanged.)

  What is the centripetal acceleration of a point on the perimeter of azsqr;d(o73 m n bicycle wheel of diameter 70 cm when the bike isdr;qo3 z7sn(m moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from tk*n017gwfak+la7 e nhyv4 (nvhe axis. What is the centripetal accenvv *17fakg4n( l 7knw+yh0e aleration?

  How many revolutions per minute must a circuksz; qi)2o/l +xn*,m) qpe7bnmrgk, ylar, rotating space station of radius 1000 m rotate to k), 2y,bsl/iom rg+*xnknzp;7 m )eqqproduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn;6ok1 hfj ,plb;y 5z-2yk 0 wdwfl,lxo at 96.5 km/h. What is the centripetal force on the motk2h 5ox6 dw byjlf,yl-f;0 wz;p1ko,lorcycle?

  A 0.50-kg mass is attached to the l .kl n iy)8v1clm4i,hend 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 nk1llvmc.ih y8,i4) lis the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a st7s4vfo 7nho )drong string and whirled 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 this point o7df4)n hovs7 is given by

  A stone, of mass m, is attached to a strong string and whirled in a veade-oqxq0b+g5c d7 q84s,k pertical circle of radiu 7,+kqqc-qeao8sexb 4dp0dg 5s 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 4 -h 6lj.ir;sy-s.a xvvg when pulling out of the dive. Whaxisy.v;a-l r6j h.-svt is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loo 5s*g9 (lj8jr7nf 4lz ot5hbwvp (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 seat58z(59 h*jjwt 7sv4lonl fgrb with only one-half of his normal weight. How fast is he going?

  The maximum force a f9uxp3hlp; *+: ianghbgcw:. pilot can stand is about seven times his weight. What is the min:phlgnc ;bughwap x:.93f i+*imum radius of curvature 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/ssr0qe wn;,n 89 ; e1vmjbmwqu( rounds 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 friction betweenemnrvq1 9e8 w;n;s (jb0 ,uwmq 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.kek8dtn ud2oe/fb*c1 s 09*qf The centripetal force provide c01 qkf9fke/td*u d8nse2*obd 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 speed of 14 m/s. Wha8gaj9 foef2(rj)fx9 cm0b-ug,d-cd gt must be the minimum coefficient of friction between the tires fef 9 jf2x0,rgg -9ua(dj cg)8d mco-band the road for the car to make the turn?

  A car is moving with a constant t*fn e5ii:zzsqn33(yrhx/w 1sat- w.9mz yj7 speed v around a level curve. The coefficient of friction between the tires and the road is 0.40 -n1rq:e9z35n3f*is xhy/ a7 zjw.(yt itw zsm. What is the 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 n-n olu:7;yh f+c ,dvc0d9xefyegotiate a 100-m radius turn at 35 m/s w, cu0x dvfyf-ol7e9hn; d+y :cithout skidding? (Ignore friction.)

  A horizontal curve on z.d5zaq 0 tzvc, zn(qlq/;(lv a 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, bankew )c8gbw9,atg)rylt*+qg * *e)c mcww9vr j8md at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is byvh. d -4(uw zi6ofp1vm; gkb0anked 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 k0scz2in2. am horizontal circle of radius smc.n2i k0za20.500
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 tw*vl5g gb ,p6f4(hh xyhe pit area, a race car accelerates 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 i f hp4*xlghv,b(g5w 6yn 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 of masu-7im xqj 1am8s $1.67 \times 10^{-27} \; kg$ 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-1 la0rjcn 0yo a 70-kg person standing on the Earth, due to the Moon? The mass of the Moon isjl0 r0-aoc1ny $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If the masses are (ikn x-ae+w9omoved to halfi 9-oa w+kxn(e of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from5mf j6p+xt,aq the Earth will the gravitational forces due tox,ft5q 6ja+p m 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 ;n- eu,nhf( nrf6tfx/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 them3 k bgbo 2p-ya8+-cc bj7(lqi Earth equal to the radius of the Earth. What is her acceleration due to gra +-qjccg8 23m(iolkap7b-b ybvity?

  The radius of the Earth is R. At what ktwd+ nq(i( a/v-x b ,si2fym2distance above the Earth's surface will t(s- f/b+ t2nvwqia i,(kyd2mxhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 tim/01 uy4y oxmyhes the radius mx/ yy1o04 yuhof 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 from some planet'wrg t*;2i h7s :f*ji7aylw,t pa urt3(s center, the acceleration of gravity isit7s(aw y:ht3 targ;i j2* pw7flru,* $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the s6 yvw g:kl5;a/paans:dth6+c urface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's:/6 a+ d5 n;lgtvcaywska:p6 h surface, what is its weight?

  By how many newtons does the weight mjoe0j v:0f5i) ar5isof a 100-kg person change when he goes from sea level to an altitude o5: r00i 5jomf)eavsijf 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A pvkxa y3d-ba. 6gd w wh5s5x,+satellite of mass 100 kg is at a point 3r above the Earth's surhwxaw.av,35 dg5 xdp- 6yk +bsface. What is the satellite's weight?

  A spherically symmetric planet2 bsyk4+ y-bu:eob-56ur*gbs5p y cm u has four times the Earth's mass and twice its radius. If a jar of peanut butt+ur 6s *mp:g5sy2u-kbe4cub- yb ybo 5er 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 S zh8) mk-et 3nyrh:hw0un all lie on the same line, with theh n8h-rwe3yh:0 ) kzmt Earth between 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 transxcpkx z 7t6vo)n0klz) )4t6qgported 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 (,nf,xbf:em m. i.e., it just skims the surface of the Earth). What is :exfmnm., ,fbthe speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a lozs7s +bn e8llmb+a/ :dw circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth iszae lbb87l /dsn+s+:m $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abovuqq+ -yi.h9t t57caeve the surface of the Earth. It is observed to have a period of 89 min. What qquy ev-a t.7i5t 9+chis 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 diameter oac7/y o2x tjy;f $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon ofq/9uvh tx)a1 m Jupiter 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. 9yo 48fg,f/mbjqd: vl Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days 4gvfd: myb l fq,o/9j8to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is w.0 ap-p 7gubs,h+tdi)5euul $7.78 \times 10^{11} \; m$ 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 Jupiterzy9t2w z sp9ifn07qy 2 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance fz07y9 2 ifznst9wpy2qrom the Earth to the Sun is $1.5 \times 10^{11} \; m$.)