Is it possible for an object moving with a constant spb2 kbuu6 dbt e,l4a1hv0yk6 5ieed to accelerate? Explaitkau2kbub,65 4bd 1el6yihv0n.

  Consider a particle moving with constantk 92b,n6h heckl,qr5o speed such that its acceleration of constant k69h nl,cerq5hob,k2 magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a c zd;8 qccoog,)onstant speed. Compare the direction of the object's velocity a8q);o ,ozgccd nd acceleration vectors.

  When an object experiences uniform circulp( f u4/xc;onjar motion, the direction of the acceleration is/ cfj(op4;nxu

  Consider a particle moving with constant speed such that its accelerationyr qe/, +wm+mk of constant magnitude is always perpendicular to its velocm m+eq, wy+/krity.

  What type of acceleration does an object moving wi7 pr.-l eont/vth constant speed in a circular path experi7rnp.-e/ otl vence?

  What force is needed to make an objectex7fom*r +1o2wm axc- move in a circle?

  When an object exper4.:o vsopyvwpwg,l bi4xb9 1y ux2:g 3iences uniform circular motion, the direction of the net for9yxi3ow,b ug:s4 yp1x.og:pbw v4l2 v ce is

  A roller coaster car is - k:k ewc /doy5niw:o rh(,oc-on a track that 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 centripetalo:yer w(c-,wd /kkonhoc i -:5 acceleration at this point?

  A roller coaster car (mass = M) is on a8ht89q.6damb xm pb6 n track that forms a circular loop (radius = 8m tbd mpqbn8x696ah. 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 point?

  A pilot executes a vertical dive then follows a semi-circulk/.mbq, ljl71ib2bbuar arc until it is going straight up.l b2lb,q17jb i/ bmk.u Just 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 of radi/0 p k:6gfs-vt/dv +zh8fx,am khmgn29fnvq:us $r$ 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. Th 38d:jiv2qgsyen it goes around the same curve at half of the original speed. What is tqig sv:y8d23 jhe 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 radius r at a constant speed v. Thedj/) ke:-n1t k-s icdnn it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around thejndtc ne)i :d1-k/ks - second curve, compared to the first?

  A car of mass m goes around a banked curve of radi00j5vpywu.tq s9 s0oano u8t+us r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the98+wq synouo tsuv a5p000.tj 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 anglkldhr ei 1f+8 g,x49ag0cz9jqgg-5 nne, but one has twice the radius of the other. The safe s+h ,g9zcl a xkge0grqnn 8fg1j4-i59dpeed (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 track is not constant, bai 1( hsud e+bm02zd4barq+j ;ut increases upward from the horizontal. Coming aj2sud a b e(ab+4rzq+i;m1h0 dround 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 arl-n 2p ) acfv+dim/2kwound a circular path to have both centripetal and tangential n)i+/2dwlmf2c-vk ap acceleration?

  The gravitational force between two objects is proportio4/5tl9 s w( ka2fneprk3 ,pbfanal to

  The gravitational force between two objects is inversely proportionazfl x u1+:f+e x,.rvmel to

  Two objects attract each other gravitationally. If the distance be:mzd( k9*ojdftween their centemz :k9df( o*djrs is cut in half, the gravitational force

  Two objects, with masses gsl69 * w9lokccq,o0e$m_{1}$ 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 mas r y3*hn 05fwzi:i6tenses $m_{1}$ 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 universal6yuzw52x v:fec +w +ns gravitation.

  Compared to its mass on the (gz+ty;40 amckur*( r1tbnxu- rh1q bEarth, the mass of an object on the Moon is

  The acceleration of gravity on thf53 bypv1 )qv ngb wx:9hc2,rde Moon is one-sixth what it is on Earth. An object of gcvxd1n5 fr3bh9 ,vwbqy 2:)p mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rockdu4,bc f.u1 5*,kgpz :zygo yzet's weight

  A spaceship is traveling to the Moon. At what point is it bekdmrgxc(xe ) (*mf/*wyond the pull of Eart*fdg r*)(mmckxw(/ exh's gravity?

  Suppose a satellite were orbiting the Earth just r(ubhwu* npz ;hb*xrh*6a6wqar 5-y *above the surface. What is its centrwx6(** 5 hu;pnbh *abu6q-rwyraz*h ripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twicemoao e/ ichc30) x5wy5 that of5cxawi ec0o5 )hm3o/y the Earth. 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-s3kg x7ho orgri,j:9 x8ixth what it is on Earth. The radius of the Moon 3 g,89jxo7ogrhxrki: 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, but planet oln ja 5+:3kkrB has twice the radius of planet A. If planet A has mass m, what is then 3k5k+ ora:jl mass of planet B?

  Two planets have the same surface gravity, but pl;*prbb/ yn9j hanet B has twice the mass of planet A. If /j*rhyn9pb;b planet A has radius r, what is the radius of planet B?

  Consider a small satellite movin4 0*61g6hroea kto cpng in a circular orbit (radius r) about a spherical pace *r g on64k160phtolanet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rot:( roas+bjm3 vol9ow1wxd)0 gates in the same orbit. Compare thewdsav9)1xm(3+w g ol j0:boro two satellite's speeds.

  A person is standing on a scale in an elevator accelerv ;*l4r zf2fgwating downward. Compare the reading on the scale togv;2w rfl*zf 4 the person's true weight.

  Who was the first person to realize that the planets move in elliptical paths anh,er(t n/f; jround the Suf(nh;ne /t ,rjn?

  The speed of Halley's Comet, while traveling in its elzhvd)h s1 ;owj c5/g,nr)c/9 s+ ngbscliptical orbit around the Su/ /dg c h+5s)c )jos,ghv9cznwr1 n;sbn,

  Let the average orbital radiufgp 6 mm4kz(0mk,w7h ss of a planet be R. Let the orbital period be T. What quantity is constant for all plan6 k4k7zmmpshw0,g mf(ets orbiting the Sun?

  A planet is discovered to orbit around a star in tlz dk1y/(sc9d 2h1 rphf1o xd ()vg;mihe 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, cr (211;9m1xfdvoddh l p(iky)zs / ghcompared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomical j3((1jtpn ltx-iezj 6 unit" (AU). An asteroid orbits the l j3tt6n( ezxj-1i(jpSun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.l8hcn w589jzzcm h8y3 o i+;cj

  List the four fundamental forces in nature.m2dd)wl+ *:zfij7 /gte( tb* acx 6g,z*dskb l

  An object moves with a constant f kq wq,tk :77rn/xzi9speed of 30 m/s on a circular track of radius 150ik77nz/wf ,t:xrq9qk m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Whatig zbp:s4r6m :eg rb(6 is the maximum speed around a curve with twice the radius? (:m4eg 6z(:rpbb 6sigr Assume all other factors remain unchanged.)

  What is the centripetal accelerat( 9tal)x w*vfcion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is m 9cw)x (ltv*afoving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from tqq-g xq/i )vm0he axis. What is the centripetal accel v-g q0/ixm)qqeration?

  How many revolutions per minute must a circular, rotating vmf sww8lybl,/q,9 1e space station of radius 1000 m rotate to produce an artificiamwe8/bl,s f,y w vl19ql gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 2) fuol9z0rf l3.o3qav50 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centrip 0ullfqo)3.rofv9az 3etal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1 .q g2rsgqo0q2.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string co02q sgqg. r2qan 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 wn**+z(epxl6 x(vno 1bne g*5x-k sox nhirled in a vertical circle of radiusx o5n nx-+vns 1b(ego***zx nx6pkel( 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 is given by

  A stone, of mass m, is attached to a strong string and whirled in a vohgedv)+fvs(* uk 3 e5itr0i9ertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weight. ee5*f9h+isrtk 0v i)vg(o3 du The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g whe*w0 f5u2tphzbax i: ,g42 /kpzaqr)uh n pulling out of the dive. What is the awuhz4 apb qugk22irp0tf, xz*h /):5radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which tm6m98wej04 )zbwfn thhe 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 only one-half of his normal weight. How fast is he going8z4tnwh9 mwjbf0 e)6m?

  The maximum force a pilot can stand is about seven gna; gnkyd: :qor9 h1ob31e.f edbu+1times his weight. What is the minimum radius of cgbua1b 11. ;:3ohn 9q+kordef:gyd ne urvature 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 y(jff 5/bgx90 wlo,ndradius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume g (,9 lfdj5bn /w0xoyfthe 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 speed of 20 m/s. The ce:o mmqaw gsdce+/3 /m5tz.l6 mntripetale l /mwosmczd6mt:a5 /. 3gm+q 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 radius 50 m at a speed of 14 m/s. What must bz0b ycur(;0th e the minimum coefficient of friction between the t y0rh(u bzc0t;ires and the road for the car to make the turn?

  A car is moving with a constan 0y fwd-an +doyeq8.8at speed v around a level curve. The coefficient of friction between the tires and the road is 0.40n f-w +0y8deaq d.oy8a. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is7nh 8bc7 rx8.- amryeh required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friction.)n7cbr 8yh8mx ar7 e.h-

  A horizontal curve on a bobf bf3wjnr/8 6xsled 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 mf wb t8h5w41gd, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i 6: jh6uf,ae+ palruxojgj1jli285 +us 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 is revolving uniformly in a ho .mz/ee8o2 dyzyl j,;hrizontal circley/2 mh.dlyejz, 8e;oz of 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 in the pit area, a race car accelerates at a unifo482g kjir/lbmeo i ovl,3:n, .2peszirm 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 blanks) rl/o8iinsbm22evi gpo k ,,ze4 3jl :.
(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 proto4l rywcq3z qzz:50z7o 6hmx0lz:vb -nn 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 persyltn/s m3j bc8e35rh 1(dfki2 on standing on the Earth, due to the Moon? The mass of the Moon/3crdlib 5mekyh3t s 2 18(fjn 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 are mxno0ze, jek ): .5jr2o)zs hscoved to half of their initial distance, what is the gravitational attractive sn 5reh)z .ek)2,csj 0ojoxz: force?

  For a spacecraft going from the Earth toward the Sun, at what distance from th1 u rek+ wh+0)gzroth1e Earth will the eg0r o1+1 ur hwtz+k)hgravitational 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 isl1 az3zlh2a9 txr u8t, $7.4 \times 10^{22} \; kg$ 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 "spaeg6i+5d wt 6gnce-walk" at a distance above the Earth equal to the radius of the Earth. What is her acce6+6we i d5tnggleration due to gravity?

  The radius of the Eap 4b(opyyxf1 )rth is R. At what distance above the Earth's surface will the acceleratioxoyyfpb4 1()pn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal66w l( lulfk6d to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to t ukll6w(lf6 6dhe acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some plf 3weelg*cvtg f56,8 panet's center, the acceleration of gravity i 5gef3,cpew 6fgv8lt*s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 j 6:vcnfpgk-fa r* ,7gN on the surface of the Earth. The Earth has radius r. If the object is raised to a gvk, r6g- n:fj*pfac7height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 10-xtbg72 lbi+j5-aqc6ouadu b; ag4 y6 0-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth ista26+q4jg 75yblgoi6dc-- au xb;uab $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg/m(( g9xeqr nc5( e-v9vs r1krnqs- br is at a point 3r above the Earth'se ernr r (vxm95(bnvcs-r1g(9ks/qq- surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass ande.2pfy k9;h1s)eg c2e9*fw vqz w9l ek twice its radius. If a jar of peanut butter weighs 12 N on the surface kh lqpk 2f9 19yw29c)weeesz;fe*v.g 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 l6 1y8(wjkwrwf5z m5 qtine, with the Earth between the Moon and the Sun. The Moon hfmk1ytz5 w(jrw658qw as 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 transportebik(0mc5drjd i:i6snyp6i9 i . +ew.f d 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 theqq .c.7j.rnt vmx+:zd Earth (i.e., it just skims the surface of the Earth). What is txn7.dq+zt cm.jq r.v:he speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circvw .hgp)ol k:0l:9j woular 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 tgol o9wlpv j::h)k.w0he Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular oo-mdav t .-dehe2da:3rbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (Th2d oa.3d: -mehd- vatee mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupitecp /exwge1 /f:(u4q,y6tg nlv , sokx5r, 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 Jupiter orbits thu+ dn lx;2,7clch 8mdeuzox 11e 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 orbital rad qg(,fjkkgt01a di30 yius r, and moon B has orbital radius 4r. Moon A take ak3ktfy0idjg1 ,gq0(s 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i39fmcv8lzj cz gxk97( s $7.78 \times 10^{11} \; m$ 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 emxo,y,2fxl/ is the average distance from Jupiter to y,e fxo/lxm,2the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)