Is it possible for an object moypx3c5un-. 1 qu3 0x zygdv4wlving with a constant speed to accelerate? Explai31 qv 50xy4udu nlx-c3p.wgzyn.

  Consider a particle moving with constant speed such 8 j6)yh)b(c :mo le:nmz hwr8o4js, tlthat its acceleration of constant magnitude is always per:lzoeh8st c wm) ,mh6 nlbrjoy8:4)j(pendicular to its velocity.

  An object moves in a circular ;/p;*r e rh: sjdacs.lhayv/0path at a constant speed. Compare the direction of the object's velocity and acj/;:* e0dsa.vl syhrcpahr ;/celeration vectors.

  When an object experiences uniform circular motion, ty5 yp+w lr a0.ey.k;onhe direction of the acceleratio nak yp+oyel;0r5wy.. n is

  Consider a particle moving with consta);krv f 8xdls0y e.aqe)yvp 9(nt speed such that its acceleration of constant magnitude is always perpendicular to its veloc8ek.vye)l( ;y)da prxfsqv9 0 ity.

  What type of acceleration does an object moving with c f3,i0kbs(xpbonstant speed in a circular kip 0s,bfb(3 xpath experience?

  What force is needed to make an object move in a circlt r-v2xv7bf p.e?

  When an object experiences uniform circuftn9sm5 n,6 rhv z77wylar motion, the direction of the net force is,5fm7y wn6 9nt 7vzrhs

  A roller coaster car is on a track that forms a ci f,un- 2+tc/cfv pt1sgrcular loop in the vertical plane. If the car is tof,tvu-t g1cpn +sc2f/ 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 trac -,oh6x9qhsls v6umjql23: u l4dc.crk that 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 3l lhxldu .24mh ,qv966qrc:cj-sso u 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 q ury10l j3zf2until it is going straight up. Just fqr3 01 luyzj2as 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 c)od6 -5w qg+ml 1xsjkburve 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 vwdd m 3gs-mesz9m3 4u4. Then it goes around the same curve at half of t w s9m 3sz34dg-m4uedmhe original 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 rad/)xm) riccbnr;l0 j-p ius r at a constant speed v. Then it goes around a curve of r/)0 cmj ilpnx-b);rcradius 2r at speed 2v. 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 radik w+hwto, 0nf 07c *kyqj/.xohus 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 00tof*h+ 7n,hjwko.yxcqw/kthe road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, 8 porum s8b7fmwi2 m-c n1/b0zbut one has twice the radius of the other. The safe speed (no friction needed to stay on the run) -nz/8m b7forsu0bcw1ip8 m2mfor 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 con.v tci.cdd26xjnk6f :stant, but increases upward from the horizontal. Coming around a turn, the bobsled team will inten6 fjd :ncckit6.xd v.2tionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an x yxytzpfz:*b +/s yz9iy7a( 8object moving around a circular path to have both centripetal and tangential accelerati:zx8yzyyf tbp+*a7i y /z9x(son?

  The gravitational force between twojeo 4x4 4p-m1cf abg,-pttyvl (:cdl* objects is proportional to

  The gravitational force betwee7uwjf6osf 5y(oewu+ 4n two objects is inversely proportional to

  Two objects attract each other gravitationally. If thjl2bx3) ;jdfo e distance between their centers is ;lxj2fdo j)b3 cut in half, the gravitational force

  Two objects, with masses qo *ko n-1oy0peb6q m;$m_{1}$ 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 masse;i ); u2 ewv-ea7dvt ;tj/,luu v;dbzps $m_{1}$ 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 unive 3sm2epso5;m hrsal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moonv;s:+c2b*ai r b0jhat is

  The acceleration of gravity on the Moon is og:rrz+xnde5:vjlj ao7+ 2 e a-ne-sixth what it is on Earth. An object o2:- zrg+5x+a 7ve :j jloenradf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, thegk pu*(2c 2a-ucywd.b rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the potlo-j kjvwkdip )l9ks (6. ,*ull of Earth's il(pdkl)*swkj .ovj,k6o - 9tgravity?

  Suppose a satellite were orbiting the Earth j z.-zu7fvd2zf47 rpwch + bd,qyq69vjust above the surface. What is its cent .d7qu ,7f-pjyzqfvhc+ vd9zb6z w24rripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth andpfgcj ) s3ir(*b.gz914t xb mw a radius of twice that of the Eart1jsgrw.tx im9bb*4 fp3c)g(zh. 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 fk a 1qe:iy0nbof5t; )* ,onbione-sixth what it is on Earth. The radius of 1i0bn *o)f :ytik n,abeo5qf; the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, b6g9 mam,.lmlb: * vnqxut planet B has twice the radius of planet A. If planet A has mass m, what is the l*:vx69lbnqmm.a g m, mass of planet B?

  Two planets have the sfu.;-lr *mdg 8.d fv3 -x.m5mvoaqaxiame surface gravity, but planet B has twice the mass of planet A. If planet A has radmmm-.*d gdvxaq5o.v; -a ifr.fx8ul 3ius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spher gr95 /4wdv0a ycvrj*r6yp.m yical planet (mass M). Which expression gives this sate0rv5d46vygm.wyp/yra j9 rc*llite's orbital velocity?

  Satellite A has twice tt n2i)-6lp- aw5xsby bhe mass of satellite B, and rotates in the same orbit. Compy )p-x62 -t5wbalnsibare the two satellite's speeds.

  A person is standing x7m86wpbh 3o3(c imzof*j4nzon a scale in an elevator accelerating downward. Compare the reading on them3nc8*fh3 bx4mozz6i ( jp7ow scale to the person's true weight.

  Who was the first person to realize that the planets move in ellipt4m nl(1izv2r6cv:f(y nlflzbp2a4/r ical paths around t((v/nla 46z2:m4fy nb ilz rfv pc1lr2he Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit dq-g70vri)ok vr,j oe4 qs3qj-k(.tfaround the S ekgv7 tqqvfio,4)jr .0o (3-qrsjd-kun,

  Let the average orbital radius of a planet be R. Let the orbital pcqa1vi)e 6rsrvs 7k2v6r5tx/hd : f l-eriod be T. What quvcf)xi-v s d2r 7eqt65:khr16/ral vsantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with tk*e fp 8fwx;zp)k f)uv *l4q1xhe same orbital diameter as the Earth around our Sun. If that star has 4 times the mass4f*f q;x1xuw8v) pf ezlkkp*) 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 thefan9q/ )pfk. h Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid ork/n9pf) .ahfqbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.cbs2w5 9a84jv 2p o yim1jv2tb

  List the four fundamental forcn5kr 86xhtqv5q0 (m bkm/p oo7es in nature.

  An object moves with a constant speed of 30 m/s on a circul:g0x(b o byf5iar track of radius 150 m. What is the acceleration of the 0b:of i gyx(b5object?

  The maximum speed around a, puhafr.p2se+(y p( i level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius( a hpri,py+.se(p2uf ? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bics5db ux1fj t 3kl3k x-r66iy+lycle wheel ojrf6 5u+kky6 sbld xt3l1i-3xf 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 0.200 m 85;vg6r e)ledfvky7m from the axis. What is the centripetal accelerat56d8f lvm gyv;ekr )7eion?

  How many revolutions per minute must a circular, rota 1ryx5, p1ohnj4d;kq5-ppqegting space station of radius 1000 m rotate to produce an artificial gravit r- ,p5h1k5;pxngyodqqp ej 14y of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius tu-j c+z tfm7j2irn at 96.5 km/h. What is the centr2jij+ cm7 ztf-ipetal force on the motorcycle?

  A 0.50-kg mass is attached to thp4v5lel,s( yv n3 dqd0y4d h6ye 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 stri0pdn,5sy edv3vqy(ylhd44 l 6 ng is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical crjpoyk1f2lq )iw*3 bgh3 r0r+ircle 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 poiro+b2w*k ri3jfyqh3 g0p 1rl)nt is given by

  A stone, of mass m, is attached to( b2ov :zc(sgf a strong string and whirled in a vertical circle of radius r. At the exact bottom of c2(o :(fsz gbvthe 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 anmgt plc v+yag-+:;6q g acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in wg y+q 6gg+t-mpla:vc;hich the plane is flying?

  A pilot makes an outside vertical loop (in which the center of n j:sj mluhz2)i 3tt 9i;k9f:wthe loop is beneath him) of radius 3200 m. z9f;:ts)wk2nj 3jmii:9hltu 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 pilot can,rpzf(*x0qf(w e sfg( stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolera(we((xzsff* ,gf qrp0te at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve withqus7/.hwdueo- - nfu9 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 frictu-7n u /fwe.-9odsqhuion between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 mv *f ,agwv+z)j 9sr)i6j7dbxl with a speed of 20 m/s. The centripetal force provided by frif l)gdizwvxv+9s ) 7a ,6rjjb*ction 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 du.6*qa0: v5sby sh9m+cjwbqpyd d9:14 m/s. What must be the minimum coefficient of friction between the tires and the road :qs.d05 : js*uvaq hypbwm6d9dyb +c 9for the car to make the turn?

  A car is moving withga fh/8 alt2)d a constant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius o8t )h/ ad2glaff the curve if the car is to stay on the road?

  What minimum banking angle is requo0 6nf j0yb;pjired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore fri06 j0 byfnjp;oction.)

  A horizontal curve on ad*m*,btp.zs g 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 rrb8/ff u- p6vc1iw;c madius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i+etrngs3vrcma(.2s2 kl n, +ks 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 u7 gc951b fwa-znoar h5xy8v/ is revolving uniformly in a horizontal circle of radius 0.505afv 7y c-9/1ou5w8hga nzbrx0
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 tneq d (nfz*)nur:+.ldp7u9yahe 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 n9q:lnedupd ry(7u + .*nf)az 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 of masbdwem jx r z717sr-xrj i:6p-x-z, 1pys $1.67 \times 10^{-27} \; kg$ 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 standi+k rn o2s1ku2cr;-n ah2jqk7;r+qz e.wmc 3v zng on the Earth, due to thes2 k2ujv+ q;r7;r-qwmk co kan2 z1er .ch+3nz 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 masses nx ::s3zt4e;xxz 3rjsare moved to half of their initial distance, what is thx:; en x3s:tszjz3xr 4e gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what .j76r8 ul ay tu5bkl,tdistance from the Earth will the guajlb8 lr75tt , ky.6uravitational 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 is lnn,e1;x w0nf $7.4 \times 10^{22} \; kg$ 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 6qms w/xm4 1v;ixz6xiEarth equal to the radius of the Eart 6xvmw zs4qx6x;im/1ih. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distancen++wa)ul z: gz above the Earth's surface will the acceun +ga+ lw)z:zleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its lne4i 8z vnl2-x- a(0 su zbdz5xpd4h6surface equal to 3 times the radius of Mars. The acceleration of gravity of the satenzs-elpnh5x( vxi az86244b-du dl0 zllite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's cecemuceut5*t l i 5-qc9y6h,v+nter, the acceleration of gravityt5 m e,9 y5ul6i+tu cchecq*-v 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 4dws9;y(c pf pEarth has radius r. If the object is raise(w ;fsp pdyc94d 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 pe2zw:l6tax 3yi j8e7kw rson change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earyl j 7tiea8ww26 zx:k3th is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at axl omec)bpfc +3xl(x n:/i67k point 3r above the Earth's surface. What is the satelli(k 3) felxc+ cplxio7/nb:6xmte's weight?

  A spherically symmetric planet has fo8yj2km9*5rf9ejviu gd o b9)sur times the Earth's mass and twice its radius. If a jar of peanut butter weig*ueyobmf8vg jris9d9 52 kj)9hs 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 on the same:ex0ms;q9),ud xuyqauyh is+l.k*s7 line, with th.)eys,xk:ss *9huyxm u0; lq d7iqu+ae 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 transported to the Moon (7h *j0froufl.
(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 Eart s0pei.:,;wbgqv uat:*ov o 2yh (i.e., it just skims the surface of 0t:o:pe o*; qgv2yv,ub ws.ia the Earth). 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 circulaa8.ax,v7neczv ;g* kqr 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 mnce7 g *v. ,;kvqxa8azean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km amb 4tq6hif d bkd,6:1sbove the surface of the Earth. It is observed to have a period of 89 min. What is the mass qbi d:ksb4h ,dm166tfof the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, hasol6spcy*78e w 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 Jupiter orbits the plan91pku0 4f tfxbet 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 s1(s d zf.g:s4 1hgoeeorbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete onedzsogge1. s4fsh1e: ( orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is qo+af(/lcl 11h/ke (lq0mcoooa 2oy; $7.78 \times 10^{11} \; m$ 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 qr/msv6z/yd q-r5fr5 the average distance from Jupiter to the Sun? (The distance from tfq6z/m/rqr r5y-vs d5he Earth to the Sun is $1.5 \times 10^{11} \; m$.)