Is it possible for an object moving with a constant speed to acgrd7s6 fmw25acelerate? Explaind26 5fmag7wsr.

  Consider a particle moving with constant speed such that its acceleratiocwv dr. 6zp 176qu2drvn of constant magnitude is always perpenp d c.ruqvd7r 2166vzwdicular to its velocity.

  An object moves in a cfb6k5yo- 3 p.pcx-bc, gz t-srircular path at a constant speed. Compare the direction of the object's velocity an f-kc.-p3bs6otyb5- zp,xg crd acceleration vectors.

  When an object experiencesc7q vt (hlk7m/i1e.u j uniform circular motion, the direction of the accelerai .7lu qch (1/ve7mktjtion is

  Consider a particle moving with core o,d6 xyxb+o9be7a0nstant speed such that its acceleration of constant magnitude is always perpendiculaoa +xe7,b9 reo6yxdb0 r to its velocity.

  What type of acceleration does an object moving w-eigt/fkot+1y qda11co9o y0 )r8 f h(1gynw pith constant speed in a circular path experow y hp+0cgk9g(a tft-1o )11ydrqnyo8 /1eifience?

  What force is needed to make an object move paj g) hyckf(q /5h;a1in a circle?

  When an object experiences uniform circular aji buj2s/,. 7vsr u bk; 2mqo,1j;mvtmotion, the direction of the net forcetsib7u , vs2r;/. j;jquom v1km,ja2 b is

  A roller coaster car is on a track that forms a circular loop in the versu 3: ce*5, csrlyy1igdosp04tical plane. If the car is to just maintain10*34uliy gcs,ceps5s: oyrd 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 (radimvt*a21z o3 ub l3*m*-zp hpodus = r) in the vertical plane. If the ul otzb mpm323*a*ohpdz1v *- 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 c7;es,eij qsz:,(p j bfollows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point,7j, q sbejzcs,:ipe ;( 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 k8jh.s 9/el,bupv5 neradius $r$ 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 goes/gewgs 26xqt9g o )nnh vq;x7; 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 second time, compared to the fiq7vwn/ ;q gxongth g92 s)6xe;rst time?

  A car goes around a curve of radius r at a constant speed v. Then it ge qa-*uhj0oq az*+4k woes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes * +kew -*jazqoq4a 0uharound the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r wi udal1 . /)zni zkgt.*)ln +hdu+elfc(th speed v. If the road is frictionless due to ice, the car can still negl ied+).)nal .dnk1uzhl cz f(t u/g+*otiate 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, civ n9uk -qjh*iajk)4,3jjhi(0j f -ubut one has twice the radius of the other. The safe speed (no frictioj3fkj( j9kaq-4jih uh)i,*ci jvn0u- n 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 bobsledytwkl;: . o8xza x:i6j 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. W8ti.ky j; x6:zoa:lwx hy do they do this?

  Is it possible for an objec7ws jb.8721; t lmbqwdo0fuiot moving around a circular path to have both centripetal anddwu27qwtb; b.f7 oo 1i8s0jlm tangential acceleration?

  The gravitational force betw16)mlg9 hu);(mwvuojkkm qu+ s2v) 9f hmved)een two objects is proportional to

  The gravitational force between two objecttp-d0swytgn9 jxk*17c:y k: rs is inversely proportional to

  Two objects attract each other gravitationally. If the distance between th4go.nol, f-2t6gg 9phx7w xl aeir centers is cut in half, thex7l2h ,.g-4 t6lpgwgfxn oa9 o gravitational force

  Two objects, with masses h 0twlv2+lw(w$m_{1}$ 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 mass;i(xr7o9kg snes $m_{1}$ 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 gravihfmu 2b wnn oun)6wvx5 /*x(v)tation.

  Compared to its mass on the Earth, the mass of an object on the Moon icotk u-nq7u,h7: pa7 mu)fs- ss

  The acceleration of gravity on y ae o;fp,z ; e/n6ishbk2ca7,kp/y-mthe Moon is one-sixth what it is on Earth. An object of masa aypbi6- nkocf ke/,m,zphe;y7s;2/ s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the hn0 fi8m j der k)khxnw80n+85rocket's weight

  A spaceship is traveling to the Moon. At what .6y3 htfotcc3point is it beyond the pull of Eao3htfy3cc t6. rth's gravity?

  Suppose a satellite were orbiting thegxx5 ciq.ee0 / Earth just above the surface. What is its c0c5 .ixegex /qentripetal acceleration?

  A hypothetical planet has a m /*l;i)de kq-bmnxz: oass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity ainz:*o x/b ed-l)q;k mt the Earth?

  The acceleration of gravity on the Moon is one-simk l+k jd+b.:a+izz4k52 tfd) kh7n vaoz6zl-xth what it is on Earth. The radius of the Moon is one-fourth that of)zk-ll6mjd7 ihtzzk2zo +n:4 dav ba+.5 f+kk the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of eka:quc( s(t:planet A. If planet A has mass m, what is thectk su(:(qea : mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of pq mmrh+;s*my*lanet A. If hqm*ms+m;*ry planet A has radius r, what is the radius of planet B?

  Consider a small satellite movin jmjpceo:b1l :ff(d+ 2g in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this fc1jpf+(lm : oj2bd:esatellite's orbital velocity?

  Satellite A has twice *gx/ q ,l-or4avhw7e j m(idp6the mass of satellite B, and rotates in the same orbit. Compare the two satellip g xrw4(lah 6,oj*/ie 7mqdv-te's speeds.

  A person is standing on a scale in an elevatqb 547hwomwc+ e5(nzewtbz7y+ h 53jpor accelerating downward. Compare the reading on the scale to the persoh5b7py h5+cob7e w ztjezw5w3+n m(q4 n's true weight.

  Who was the first person to realize that the planets move in se 3 kb7 qm4r9c*n6t nw6im m2+szil9xelliptical paths aroundck ni+z2 m4les6nt63 9imq7wbm srx*9 the Sun?

  The speed of Halley's Comet, while trkxzr cj72gh/srxf u; o6)rc8 1pz(o6qaveling in its elliptical orbit around the Suzsfr8 xp;(gjro6zqc ux c721r6 )ohk/n,

  Let the average orbital radius of a planet b9mk(rfh4lq8d 8 ng,zq e R. Let the orbital period be T. What quantity i9,qf8 z(r4lhqd g8knm s constant for all planets orbiting the Sun?

  A planet is discovered to orbit aroun6 qrpfpwinz:v s1m)ev4yf)/ *d a star in the galaxy Andromeda, with the same orbit) iv4fp s)rp e /m1nq*fw:zvy6al 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 "astronomvhh fm4-n8)xwk6z(nx 3a*jqr ical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?zf *xhjn6nw 4hvqkrx3m()- 8a

State Kepler's laws.o3 qp+8tc+ w+snqd d.g

  List the four fundamental forces in natigkf 6k /pyf*-)qk8/ f nsbw+lure.

  An object moves with a constant speed of 30 m/s on a circular track of rad iu :d:d1,mhudius 150 m. What is thud,i1d hm::du e acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the m8:c; jq9yy/pxfdujc 7 bk;u 5uaximum speed around a curve with twice the radius? (Assume all other factors remain unchangec/ucu:b 5u7jqk 8 fxp;y ydj9;d.)

  What is the centripetal acceleration of a point on the pwmcf5)(uxkh 4*tq +p:chy 8ey.6c k ezzi0nm9erimeter of a bicycle wheel of diameter 70 cm when the bike is moving hkck5(4 my zmyeq80tf+ i .*ucz e6h )pc:9nxw8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. W:q9fv6a(tl y8u4 gvhzx-f xh 6hat is the centripetal avl8utq4hxyz-:f (a6h v xg69fcceleration?

  How many revolutions per minute must a circulwx/ls p 0s.lv d2-yhh4ar, rotating space station of radiu hdpsx l4vshl2/0y-w.s 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It g n4 +e4vqw0g(g,x*ls pe 4vzbgoes around a 13.7 m radius turn at 96.5 km/h. What is the cent ,* gevb+(p4zl4 w40ggvxesqnripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Ts6 iuz.0h7nlpm3b a-jj anlf+c3/oy2he system is whirled in a horizojuh03b lp 6/zso2 laf n3ma+ic7.yj- nntal circular path. If the maximum tension that the string can 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 stlxu2h l 4h.s( .dc4dsh1t ,(6flhpjw zrong string and whirled in a vertical circle of radius r. At the exact top of the path the tension inhcus6 2fd (,wsz h(1jhhld4t.. x lp4l 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 7xi5 fcy3f 3q3sr0 1eox0hhum 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 is 3s73i ox hx cfhye05m3uqfr10 given by

  A jet plane flying 600 m/s experiences an accevr;hvsks w h 2m*w3:*mxwl, ;wleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the pw mvhsvh m;*,r;:w3 w*x2k lwslane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop ik-eovfvn 6j2ohj538 zs 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 n z5 oh6vkj32f oev8j-he going?

  The maximum force a pilot can s:jk,)mbum qh :);g (+lbnxqs-k gzz,p tand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilg); +qul, p-n(zmb bqz):kgmkxh sj, :ot, 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 radib amp (t ksf99wcfu*d:r6)hgo b94zo+us 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 between the car'ffz69 +ghpatk4 u*cmwb9dso9r) (ob:s tires and each road surface.)

  A car is negotiating a flat curve of rch96++ gntxt:0q wh2 f s6tptvadius 50 m with a speed of 20 m/s. The centripetal force prov 2hv6 tfttsq0+9txp c:hn6w+ gided 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 sp+vxw19uol o.0:yy zx mohe +5yeed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the.5y 09+l1+emouv xwo:h zyy xo car to make the turn?

  A car is moving with a constant speed v around a level curve. The coe vu,z*hnb0h og2w- ,f;s1 sf5ij/cvjj fficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if theong5j01 zfh *jfv2u, j, h- i/sbswvc; car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled t z:zj(4)p i-0 vhdt6bwh.hsfno negotiate a 100-m radius turn at 35 m/s without skiddingtf i snp z6hh 0-:(zdbv4jwh.)? (Ignore friction.)

  A horizontal curve on azo +wvjhbynnkfd6 lm)y+fc;b z t:3.:mr9-6 s 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, banked at an angle of /xn tg6 zes,)u$45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 mea-bzq -vhrt t;d*pea-5a, l ) is 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 horizont4:ua(l : ibg vjqloiu+dqk3)gs35g7lal circle of dai:5kvo3q(j+: l37 g gb s 4luqg)luiradius 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 ad/kxvghxthw) g8 04h+ ccelerates at a uniform rate to a speed of 45 m/s in 15 s, moving h 8xwh+)gh gx4tv /kd0on 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 of mtlu)r u vu7l66ass $1.67 \times 10^{-27} \; kg$ 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 o0gz, x gft)od3n2g 46sh rax1an a 70-kg person standing on the Earth, due to the Moon? The mass ofs gh 46zdgxgt 1af2n x)ao,03r 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 foc ,8fmbbgqs 7,rce between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attracti,qmc ,8gbs7fbve force?

  For a spacecraft going from the ;tod nhonz6i; .74m efEarth toward the Sun, at what distance from the Earth will the grav nd 6io nmf;tz;7o4.ehitational 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 iz avxftn )r7ql,.)bw8s $7.4 \times 10^{22} \; kg$ 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 Eb*j)i2gq). hd+xpi ki3wbhg ie)ky6* arth equal to the radius of the Earth. What is her acceleration due to grh*+ig *dieyix k. ) qw6j)bhkg p2)ib3avity?

  The radius of the Earth is R. At what distance above ths rm o/g-i1p-fe Earth's surface will the acceleratpfmoi-/s- 1 grion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mat99b0clr thr 3d 5y6mirs at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfachr3 5b0ct r9mty9il6de of Mars, is

  At a distance of 14000 km from some planet's center, the acce:xgj m)q d:pa)v0mdm /ku2l 2ileration of gravity isxpjdil/mgd2:q akmm)2)vu0 : $32 \; m/s^2$. 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 radiue l 3h(/ztkpl/0yd7u hs r. If the object is raised to a height of 3r above the Earth's surface, wuy z lh/t/l0kp d3h(7ehat is its weight?

  By how many newtons does the weight of a 1ld 5h;q si.s /zd-ej0f00-kg person change when he goes from sea level to an altitude ojs0 ql/f .h5esi d;z-df 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a pr0f4bqom +ggs -.0e ixoint 3r above the Earth's surface. What is the satellite'oxi +0r0 fsgb4m.eq -gs weight?

  A spherically symmetric planet has four times the Earth's mass and twice its r,ilizr :z o6 1gc)zvv/adius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on thezo)izrg 6lz :vi,/vc1 surface of this planet?

  During a lunar eclipse, qsp.a7g v91ws the Moon, Earth, and Sun all lie on the same line, with thea9w1 7qg .svsp 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 ttg .((qe mq*wkransported 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 (4,*vt zie prlwt l)*h(e1(*-1mesqbz +gxr txi.e., it just skims the surface of the Earth). What is the speed of the satellite? (Ttl(mrhltqzez i**p*)+tb,4xvr1- wg ( e e1xshe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbi4spf:9u+zz ( oytjxddr(;9 )c3 kpm cat about the Earth (i.e., it just skims the surface of the Earth). How long does it ta +xj ky:dc 9 3mzr)sapfu(4t;opc(9 dzke 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 abovk(gct o g7/n sy*+ck5ve the surface of the Earth. It is observed to have a period of 89 min. What tons75yc +(kgg/c* vk 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 napq tp9q9 6tzqs*i-1mwk)z 7 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 orbitsfb a *)as(zf9nl0sw+g 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 orb9ke0lkjiny3 :kz+( i kits. Moon A has orbital radius r, andi:(3 zyl9+kji kk0k en 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 i(5+ xl.vcea s+9 ijppps $7.78 \times 10^{11} \; m$ 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 Juqe nk6;vih +0wpiter 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sunw+ ;q6ihk0evn is $1.5 \times 10^{11} \; m$.)