Is it possible for an object moving with a constant sfd ln mwa/fx -/hd5,6cpeed to accelerate? Explainwl cn-/adf hxm/6,f5 d.

  Consider a particle moving with constant speed j 99br7u ar9pysuch that its acceleration of constj799b r9ayur pant magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the directio;ms xhl:/ zvj09z+xefn of t0: lvz9f;/x smhx+ezjhe object's velocity and acceleration vectors.

  When an object experiences und agcn xd7nc5gzee///l 7me1(iform circular motion, the direction of the accelerat g7//lxcenagd ed(e /5z m1nc7ion is

  Consider a particle moving with constant speed such thas.p./k+qyt7k .fy s mst its acceleration of constant magnitude is always perpendicula +yt.f/ sk ksq.m.s7ypr to its velocity.

  What type of accelerau5o qw)u 9vidh* vmw* (3daqno- n3k03rdgwj0tion does an object moving with constant speed in a circular pat -dv q mauw wv0*950q3d) k(jnr*hudio3w3gonh experience?

  What force is needed to make an object movefa ep)ia.bdm7/ mb/f2-u lg-v in a circle?

  When an object experiences uniform circular motion, the direction of th0t5 gkz+ vum,8wgre2re net force is gg8r,0rtv5w+ku2m ze

  A roller coaster car is o a5kwy*eag2i5 n a track that forms a circular loop in the vertical plane. If the car is taiy*k52 wg5ea o 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) nl) +hxp2khd a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the tra)nlxkd+ hp2)hck 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-ct xa gn ,+ 67*d1ef 7m(byt.t,,tgfk6atolzfnircular arc until it is going straight up. Just as the plane is at its lowest point, the force on him ia,gx 6o tztg+n7 af,6 71etkt*l(f nbdmyf.t,s

  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/yiku bp.c(;rurve 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 spe4ze,zea k f p*bzb 5g77cq0e8ned 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 qz 7a8e4,nbf ke7p*5zgb zce0around the curve for the second time, compared to the first time?

  A car goes around a curve of radius 9i+mam6 h:bbtr at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is 6 +btb9am :hmithe centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banv.wejyfc39;gxvi0 d+rda) w5ked 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 card ;.ywf0jw 9i grecvx35vd+a ) from the road is equal in magnitude to

  Two horizontal curves on a g+b bx +n-6tww9kuqm+pc8/hi bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve i9cm xk +t6g8/wpu bnq i++wb-hs 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, b n15knu4i8j54fzfzpvhm 3i w 0ut increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming o4ifhmnn iv 4f1 5zwj05p8z 3ukut of the turn. Why do they do this?

  Is it possible for an object moving around a circular pm e(63k:)1o7tpuaewvitkf7wc5pdw5 ath to have both centripetal and tangential ac(7wp w)eic1:w3te t6uk5om7k favpd 5celeration?

  The gravitational force betweengh amy 6 e3- vc+i.k42yx ttz+ehlxn-: two objects is proportional to

  The gravitational force between two objects is inverse5yq 00xct74vdhm 9i aply proportional to

  Two objects attract each other gravitationally. If the d,e(sup 88f ywvistance between their centers is cut in s,yv88 fuewp(half, the gravitational force

  Two objects, with mass3wzj :ggzl9 a(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 masses y dr:j;0 mi(uh wmd*9x$m_{1}$ 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 universal gravjjrjcz yf0(4 j o/p:k)itation.

  Compared to its mass on the Earth, the mav:ctas)r0w. p ss of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what ity (sk.fr3mxr b7xir)** jgiy. is on Earth. An objecry* k7m) yjb*i. .sx (xri3frgt of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, thejh:dn9ef( xwp:56d v a (tyn4k rocket's weight

  A spaceship is traveling to the Moon. 7 yhwwld l;xpxp;17*ype*49 0 poucid At what point is it beyond the pull of Eadhwl c1i p0dl;4po*wxx7;y7pe*yu9 prth's gravity?

  Suppose a satellite were orbit +h5y. 1 k0 m zy:of.tuodu3zutz5gj)ling the Earth just above the surface. What is its centripetal accelu 51ym oyok3z: gh0t+fl ..zdju5 zut)eration?

  A hypothetical planet has a mass of half that of the Ea oqcks:f/e 3b7rv4 zc1rth and a radius of twice that of the Earth. What is the acce7cr ev fc13qob /zk:s4leration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravy;-n(kjvcnh/1l 3wq zity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourv31cw z; (n/nklqjh -yth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface 3m ftmeq)w;u8g h5xa)gravity, but planet B has twice the radius of planet A. If planet A has mass m,5g ; fhxtwu 8)ma3q)em what is the mass of planet B?

  Two planets have the same surfacej jnxibs: + vc4n325ve gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of4c n+v52 j3:xesb jniv planet B?

  Consider a small satellite moving in a -1t c p)u4h. ygsx3qmkcircular orbit (radius r) about a spherical planet (mass M). Which expression gives this sc s41t3m y-) hpxqg.kuatellite's orbital velocity?

  Satellite A has twice the mass of satellizr ,2 .c2me7exzi*p vj/xwz6 dte B, and rotates in the same orbit. Compare the two*z ,xc/ mvj d .ep67ie22zwzrx satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Cx8.6x9iomms a ku e47d*lh-u fompare the reading o*elm k .8i7hx9dam-x64uo fusn the scale to the person's true weight.

  Who was the first person to realize that thrf 3e/(k.;zz+fqz esl e planets move in elliptical paths around the Suzez s3rlz(q./ ffk +;en?

  The speed of Halley's Comet, while travelin 3-m4itsi/ lypg in its elliptical orbit around the Su-i ims/4ylp 3tn,

  Let the average orbital radius of a planet be R. Let the orbital period be.(xptp;q wty ,y(xe1 e T. What quantity is constant for all planets orbiting te1yq;pt. ,(px txw y(ehe Sun?

  A planet is discovered to orbit around a star in the galaxy An1rhywy6uwm7 2h dk/.+cw 2npjdromeda, 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. h6wd2 pjhy/1ncur+ mww2 y7k of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as or+1u*fr 4lij(hwf:.d pfk -kzne "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the *p i :w frl zdfjkrhu+.f1-k(4asteroid's average distance from the Sun?

State Kepler's laws./1pu7 h i.a,wcv d9wvzgw ,j1s

  List the four fundamens57j2d lnh1 nztal forces in nature.

  An object moves with a constant speed ozgg4 (v1c 2nalf 30 m/s on a circular track of radius 150 m. What is the acceleratizl ca12gnv 4(gon of the object?

  The maximum speed around a level curve is 30.0 km/h. What is z-le1 6c*, hf 6fedrmothe maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.) cfem6ho- l1*,zedr f6

  What is the centripetal: un*agwu-1-,c kf has ;g.oaf acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike*:s aow,; kaa.-fu ghn1g-fc u is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.2 / xxi y1tu jyyqxd2id6g3m*3200 m from the axis. What is the centripetalxti1uxy/3ymix2ydq*j g623 d acceleration?

  How many revolutions per minutzujy jk i//2+eax5xk/e must a circular, rotating space station of radius 1000 m +2kyej/ za ji xx/ku/5rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m rahr-+rgazd g r f07honje**/uu3+tu a;dius turn at 96.5 km/h. What is the centripetal force on the mund ufo -*/ute hjg+z grr7*r3ha0;+aotorcycle?

  A 0.50-kg mass is attached to the endlqf+wm0g 69 cn 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 th c60mflnw+g9 qe string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical)znaz--q 5zd p,k nd6d8mze4e circle of radius r. At the exact top of the path the tension in the string is 3 tim) ,-nnee5d6 4dzzpaq dz-m8kzes the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirlrzu783td hlv -,w1oaoed in a vertical circtuh 1r-78,dola zow3vle 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 given by

  A jet plane flying 600 m/s experiences an acceleration of 4g whe*3nhx(nu5;e halgm g6 +2rbb2z k an48ayc-hwn pulling out of the dive. What is thex25zh-gab elnhw8 6agy (b *r3kcna mu4;2h+n radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertica6svfpbnawk1 a147,o .4g h kmgl loop (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 seat with on 46p vwabkfahs,mg1 4g17.nko ly one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven +)s2 w+eiatx7vcerlx4if- 1 utimes his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out s)xec+1i e-7ul +ixrtv a2 w4fof 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 thatbknzzj vwx)g/(4s* ,x d :j,e tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume tt*vdj(kjasz w4:,xzng/)x b,he same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat c gepo(f) v79 hzc. 9.svq+vzcfurve of radius 50 m with a speed of 20 m/s. The centripetal force provided by fric)9o( v.v7v9fzp+ esc q. gfchztion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of *4lir t4pt) 2rb vwq:x*/v gsdradius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car tor)r qp* svv4i gt4b2 /l:*twdx make the turn?

  A car is moving with a constant speed v around a level curve. T,3 ,dq zh4hcqohe coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if th4qzh3chq,od, e car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled dh gd5/ :owjj2i7t;yhto negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore 5:y;goh 2ij7 /twdhjdfriction.)

  A horizontal curve on a bobsled run is u 1,jh,8ma)f:(qy9bq o,j. wwrxlnw ebanked 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 -ybx5 y f6lrhqc:yp,(at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 8uuhq*:xcs* i07 v sua$45^{\circ}$. 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 strup: +e8 shq/xsing is revolving uniformly in a horizontal circle of rad :sp8eqs/u x+hius 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 unizb267nv4 c;q( n6ewzdfe) uz wt5top6form 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 in the blanz6tfe5z 4 b2oqn7v ud(t6;cw)ez6wn p ks)
(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 pro.4xhvu .b9tu 8;lr fmeton 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 to kq8haj.3 . kbuthe Moon? The mass of tb ..ka83qhkujhe Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational at y./q,( fqs:lzzh(alhtractive force between two masses is F. If the masses are moved to half of their initial distance, wh(,z.q:q(f alhysh /z lat is the gravitational attractive force?

  For a spacecraft going from z1ftqlb0 ) gm:the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Ebt 0lqz):gmf1arth 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 jp yth*qgn am:a xxy 2/)6bif6 g.g()l$7.4 \times 10^{22} \; kg$ 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 if gczm6 /9+nk/fpn t1"space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration dun6+ktp9 zff1/gcn mi/e to gravity?

  The radius of the Earth is R. At what distance above the vh2v v+puu1logvj- a dr.p:) 5Earth's surface will the acc:a.2v do5l vp up jhugv-1)r+veleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times theo7r7-uu y7-xybqw pz,42ejel radius of Mars. The acceleration of gravity of the oy7,ue7l x -rw2 4zup7yqb- jesatellite, 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 gravityyo,dq 7grok798i;u j c is k go rducj8y77o9;,qi$32 \; m/s^2$. 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 Eh +x 0jvuxo:2garth has radius r. If the object is raised to a height of 3r govujx+0 h x:2above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change36d w vgu9e/5qvlwp2 k when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth i gl3ud5kvp ww/ve629qs $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kgh92p xvd, 1twr is at a point 3r above the Earth's surface. What is the s2rv,hx d9wp1tatellite's weight?

  A spherically symmetric planet has four times the Earth's /fya,hycip)7 mass and twice its radius. If a jar of peanut butteriy/fypch a) ,7 weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipsw)xmw gewv- /hl*:ow 4e, the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass o/w hwg 4-w evoxlm*:)wf $7.36 \times 10^{22} \; kg$; 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 ball8h vho5f 8sx- k1z t3(wiybv9j is transported 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 75 jx ;le7kwlx )y)myncircular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius o7wyej n75x ;) ymllx)kf the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it j :s2mhsuvf,wl+34e h hust skims the surface of the Earth). How long does it take to make one revolution around the 3hsf,eh 2sm4vl w+uh: Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbi5xsy 3jp-kc1 +tuon:mt 230 km above the surface of the Earth. It is observed to have a period of 89 min.5s-muojxtkny 1+c3 p: 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 orbital diameter of 2s wn/t w0lv el)iw8p(z/r/ms $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Ju2dcwu.: 5xskce 6o;hm u:my5 ppiter 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 ohp9nf b ftol)0 x) :i+dni8xb*rbital radius r, and f:npx n0dixob i89lfb*h+)) t 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 orbit?

  The planet Jupiter is kpaj; zf)8swhw 4o 5rp4dm4r0$7.78 \times 10^{11} \; m$ 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 Juxryry0*v9 feeq an/,9 piter 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? qey,ye r99/n*avrxf0 (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)