Is it possible for an object moving with a constant speed to accelerat)j(epm1adb1 ge? Explai(ejm)dbg a1p1 n.

  Consider a particle moving with constant speed suche; yao*ju00qy that its acceleration of constant magnitude is always perpenyaoj 0*;yqeu0 dicular to its velocity.

  An object moves in a circular path at a constant speed. Compare twt1rkqd7vy8q9rf 8 ljr7i1n8 he direction o7jlr78tvq k1q9i 8nfr8w1rd yf the object's velocity and acceleration vectors.

  When an object experienqfp wqdk8b675i3mb f 4ces uniform circular motion, the direction of the acceleration 7 qidb q3pffmk8 54w6bis

  Consider a particle moving with constant speed suc/z+,;u2mv28eog 6xe8naw lneiu 1idsh that its acceleration of constant magnitude is always perpendicular to its velocity18 u2;8zwxe2sdeiug /+m,l6 on aevni.

  What type of acceleration does an object moving with constantvt p 2h/v-6sno speed in a circular path ov2/ sh-tn vp6experience?

  What force is needed to make an object moswx: go19i3 alve in a circle?

  When an object experiences uniform circular motion, the direction ofw4j0vr qry1 y ,l9nfdu,gj *:r the net forcejjy 1l4wrd*q,ur0r9 v,n:fyg is

  A roller coaster car is on a track tha7lmt;lst5wi fz- mt/0t 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 centripetfl -mtt/z0i s ;wl57tmal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular lom vtz.1 cl+arz qg,c )hk.f(j4op (radius = r) in the verti.zjh,rq1gz(c)v 4cl.t+f kamcal 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 vertikvx5,s7p tj (vcal dive then follows a semi-circular arc until it is going straight up. Just as the plane is k,j vv(tx57spat 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 ie ap;4t8 n-ubradius $r$ 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. Theny 6;n t2prlm4 b6bhdebi 33-ay it goes 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 first 4b a2b36 inby3l -pedy;6htrmtime?

  A car goes around a curve of rad6y j:qxacs n:f a5j5q5ius r at a constant speed v. Then it goes around a curs:qyn5 565j cx:qfajave of radius 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 radius r wi wp7tm; /6k bp*bohz:xth speed v. If the road is frictionless due to ice, the cat6bo ph ;bm/z:7 xw*kpr can still negotiate 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 bobsd :(. g,czpfnu0:*nhzx*t gd wled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no fricti*ufng,hp.nt d( z ::0zwx*dgcon 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, b 0i4lluk p6syz*-d 2avut increases upward from the horizontal2lu4 v-pda* izs 0ky6l. Coming around 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 around a circular path ybz /fingf ( 3s1bf-pi h3cf64to have both centripetal and tangenh/63f 3fg pc i-fsybbz in1(f4tial acceleration?

  The gravitational force between two objects is prp;) hpj.0.m woycp.ol oportional to

  The gravitational force betweez/+4sxemd.;a1 u 2syfvy rh+2emx ae8n two objects is inversely proportional to

  Two objects attract each other gravitatid.tu6 k /oaq1zonally. If the distance between their centk1z /o6u.taqders is cut in half, the gravitational force

  Two objects, with masse*ii o-)gn*s k7n:0;0ghm2 dqu zs bhnfs $m_{1}$ 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 masbxzpuhqq0i3g1r4:k gk*v ;d5 ses $m_{1}$ 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 universu; w8pdbheh knxj d.; *k/qd33al gravitation.

  Compared to its mass on the Earth, tqne,01lh;i8j; qgh n ihe mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth whv(p - t1zr8aezat it is on Earth. An object oe za p-(t1r8vzf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from)2hwvo4sa 1 zpb :45zznv4/ )xgfdcbv the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it+ nx-erp xsl (e/m -c/sil-ab* beyond the pull of Earth's g xe /l/p(sbrmx+*n s-ia c-el-ravity?

  Suppose a satellite were orbiting the Earth just above the surface .77g5stirbi d 0 usp3q20yvtp. What is its r70s t psy7 .iqp52vg uid30tbcentripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radiuhhdj kwio (y9s r2xr+ wp3n/3+s of twice that of the Earth. What is the acceleration due to gravj 9+owp rx/3(n3swhh2d ri +ykity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of grc klgyyd5)p4 )avity on the Moon is one-sixth what it is on Earth. The radius of the Moon isd)yky 5gp)l4c 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 B*sdo8uhwi: 4 r has twice the radius of planet A. If planet A has mass m, what is d4:sur whi8* othe mass of planet B?

  Two planets have the same surface 4vk14cptn gv1tivp rqwj)01*gravity, but planet B has twice the mass of planet A. If planet A has radius r, what 14j*t1vv pgw4ncpk0r) ti1qvis the radius of planet B?

  Consider a small satellite moving in a circular orbit jt .8 hp-((zr6t wgqop(radius r) about a spherical planet (.pwq8 gj z-6t(ort( phmass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, an0 lr tti*rl;wui/fa:3d rotates in the same orbit. C0rwi */ tu3lr; liaf:tompare the two satellite's speeds.

  A person is standing on a scale in an ei ocvykw 5yr +p82-,qwlevator accelerating downward. Compare the reading on the scale to the p5-cwpoy2 ,wri k+8v yqerson's true weight.

  Who was the first person to realize that the planets move in ellipfr99rnf(o ;;toe jfmxg 2-: d 9mg1otitical paths around the Sunom oo-1; :mxftt(gg 29nfj e9f9;rdri?

  The speed of Halley's Comet, while j iq5rz66h4us, ( mmietraveling in its elliptical orbit around the Sujze ruimh(4 m ,q6i6s5n,

  Let the average orbital radius of a planet beyjxd:t0 +r,h dbpa6v8 R. Let the orbital period be T. What quantity is constant f,b8 d:dh ajyr0tx+p 6vor all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with psqro;8t qp1l,j,y6lthe same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what willslry8ljt,p61, ;oqq p 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 ud0 9umxh 5jrp ar 9+ipprxm6;4nit" (AU). An asteroid orbits the Sun in one-third of a year. What is px905xjrm+rp i ;9m4 a6pudrhthe asteroid's average distance from the Sun?

State Kepler's laws.8 e--trbrl:) tqzl6c g4 u)ubs

  List the four fundamental forces in natu(nj+japu*vkcitm51 8 re.

  An object moves with a constant speed of 30 m/s on a circular track of radhx z hg;:;vtyalaej1;-jy/md94 di(jius 150 m. What is the acceleration of the 1thjyy(9i/v; x jadamhgj: l;e;d z4- object?

  The maximum speed around a level curve il 6iwxmve a7m4n8sb *0s 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assu 7bmwal 46*xm0nvie8 sme all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perime:egpwj83 mh0t ter of a bicycle wheel of diameter 70 cmh0wgt: pm 38ej when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 jmu:p ps4h78;xu816 tlslw tt rev/s is located 0.200 m from the axis. What is the c7;tuu:sll tj8x h164wmtsp8p entripetal acceleration?

  How many revolutions per minute must a circular, rotating 7dmh;- :yewii space station of radius 1000 m rotate to produce an artifiwyi: d;7meh-icial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius tur3 ltd0/.myiwlm0pdy vbc 5 4(/bmihql-a*q9sn at 96.5 km/h. What is the centripetal force on the 4yb3wc9t ih(p05bqi*.yv- llsm/qad0m md /l motorcycle?

  A 0.50-kg mass is attached to the en.c46fyna2u 0u qycs5gd of a 1.0-m string. The system is whirled in a horizontal circular path. If .y0ucfsagu54ncy 26 qthe 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 strong string and whirled in a verxyrd* tvynd0imlgl+3 *9 l(*dtical circle of radius r. At the exllt+dx r *gdyvd0( *3nlymi9* act 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 attachef7hdx qr.y.z+rtb t 3vi48.r(s5 m9g1nlj l nmd to a strong string 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 p . nvzs jdqn9rgr4.i1t br5hxf3 tly.m7(m8+l oint is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling of 3ky vz byij)gj0*0o( vfy1 fuah/5r/ut of the dive. What is the radius of curvature / g)ffzyyrhi /ok1bj5avv3 juy* 0f(0 of the loop in which the plane is flying?

  A pilot makes an outside vertical loop l-rv fhhez :)f:kt5x+qz5evp 1fx5u . (in which the center of the loop is beneathqet5pv+5 xefzk:h ru)1:zx5f lfv -.h 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 going?

  The maximum force a pilot can stand is about s92qcb4dwgw6ad)n :a2q h d 5leeven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulliaa:dl bd 42)h q2we6qgdw5c9nng out of 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 the tires on f qx hue gk*jirg0 f,ixb4,;;(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'sb;h0,kfixr ;gf4 ( u ieqgjx,* tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The cebva41grx(lf 2: 5/ykk9yd f23nncv nyntripet5 2kgv91al4yv(fcy n/xndb y 2k3:rfn al 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. W (p kg2gcgxi9p,cean2v:6- hyhat must be the minimumph9-gnga,c :( pex26 g 2kyicv coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The c 4(q4kvyiu)di)5sqs9 nug au9oefficient of f9q dniyk)uivuuaqg44(9 5ss )riction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is re3qbdc i db0k517:;d*1i2 eqkxshkl h dquired for an Olympic bobsled to negotiate a 100-m radius turnd5k 1q:qbcidk li*s0kd h;7b e13hdx2 at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsleg h1*j7q +julmiso, k1 c:sw/m*stwz.d 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 radili +flb,a;pg, us 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banvba21. v7kqy hr,j3u,ni0 rm yked 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 v* s7 g70elq*gulp,r;p sa3vt a horizontal circle of r0 pr*t3e* ,77s vsvglq;upglaadius 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 uw ,fmd8yi39ipniform rate to a speeddimi3 8f ,ywp9 of 45 m/s in 15 s, moving on 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 i k 0n.0nldk4jof a proton 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 Earthydhh0-3 o)p-( 4g vnv dryut8e, due to the Moon? The mass of the Moonydhrnpe oyvd3g 8v u-0-(4ht) is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive forc-j8x 1z5c+u z ncff7/71ch0cmald ccke between two masses is F. If the masses are moved to half of their inh- c8clcnu c5 cf0 daz7jfc+kx7z1m1/itial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance f-n01xie r1x5 j a1wqhtrom the Earth will the gravita-5t jre hn11xi10ax wqtional 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 ip 9gbt(5cqve 2ep:k .i t*xy6ls $7.4 \times 10^{22} \; kg$ 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 abovev6s s7)md4,r;imdr;h ri9 i1ypa 1 ecb the Earth equal to the radius of the Earth. What is her acceleratiriiy9m6r rp1hs;dmsa;b dc)i,174 evon due to gravity?

  The radius of the Earth is R. At what distance abe3;kw:)rvhmi s n 8-m vjbkikm6x 92fn,x h;d+ove the Earth's surface will the acceleration kfrhm-i 2m +e8 ;39x dinkhjsxwbvm6n,v:;k )of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equ.jnrifs/ dv /5p*nc4er9)jq: pt *.;v qnmzkval to 3 times the radius of Mars. The acceleration of gravik .vne/ vr4)d/5pnc t*fqq* spj;m.9nj:r zvity 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'/q2z gfi+yyer; k- iv-6b +yhrs center, the acceleration of gravity i g-y rbv-yfyhi+26ie+q /;z rks $32 \; m/s^2$. 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;p:r q vwdz ny6y-yhd1k x,ej85 :ees8 has radius r. If the object is raised to a height of 3r above the Earth's surface, what is ih,q5k p:j8eey dn d 6xzey;-:wvysr18ts weight?

  By how many newtons does the weight of a mg1j+3 xgyf vqzr4 4h6e g)7ida1,qkx100-kg person change when he goes from sea level to an altitude of 5000 m? (The gz1rxe14+yxfgi,4h 6j 7daq) 3 kmv qgmean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellitm0t9 y h dvcnn6t1(o-p/qt od*e of mass 100 kg is at a point 3r above the Earth's -tto9nt /chdq6v1*m(n po0y dsurface. What is the satellite's weight?

  A spherically symmetric planet has m r uve r6ek-wqvy+4/-fz6mp;four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surfak 6qwm-vym46p -uv/r zee; rf+ce of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon,;7xgwt 5m:zb y Earth, and Sun all lie on the same line, with the Earth betw7w gm;t5xz:b yeen 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.nx7 pu;8s,:wplrfa i. znau/*
(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 e7(e/o ft h+jrva2yu,(cw/ yk low circular orbit about the Earth (i.e., it just skims the surfaceatwuh(+c(jo 7/y e2f/y,vre k of 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 circular orbit about the Earth (i.e., fcktx yj+s 24 jh0o0j 5yzx*a+it just skims the surface k4yx c2z*j y0axs5o 0jth+jf+of the Earth). How long does it take 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 above the surface of th63l z5q3uy:x h5ve p7)uij mwhe Earth. It is observed to havez5lu :hvyhmjiuxw6 )q7e33p5 a period of 89 min. 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 diamete/0cpddwb h e- gytp(2*r 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 planet withpvwd:omn c0c c4g/fn,(8h n ewh 5le(. 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 cirdgpk;2,r4-8cj t2zb+j avm3 .gbl )bwjb ,stj cular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long do 2vb,jt g;b-c4rb,8m pj3. bw2jtldg+s k)zajes it take moon B to complete an orbit?

  The planet Jupiter is upr3g.m 5pn lsmyj*20$7.78 \times 10^{11} \; m$ 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 ye,k :15fi stiru2: fkdbars to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The dista2urfs i5:kf ,:kti1 bdnce from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)