Is it possible for an object moving with a constant speed to accelerate? Eucx 1aut- w 2o)goaoc)l, (/yhxplainl 1h()-cu/w),cyotaga oxu 2 o.

  Consider a particle moving with 5 fg-rld0cfmpoj 4w 3l i,+)ueconstant speed such that its acceleration of constant magnitude is alway+ 4-mwl, 5g0ljffpdo uric3e)s perpendicular to its velocity.

  An object moves in a circular path at a constb9xnu suq155 lgzw9*m c:.)tt o ulwg7ant speed. Compare the direction of the object's veloc79gmuwulc 55t)ogb9:.z xl*wsn ut1q ity and acceleration vectors.

  When an object experik xo/e7q- ;txun;d n0-t-xoumences uniform circular motion, the direction of the acceleqd0 tn -oeu;mot 7xku-x;-xn/ration is

  Consider a particle moving with constant speed such that its accldt)p 6t n:q8whv0zq/eleration of constant magnitude is always perpendicular to its velocivzhnt/ ) 6p l0wqt8qd:ty.

  What type of acceleration does an object moving with constant speed in a ci;(k 5p ijx9,e*ppcn omrcular ppc(mn *xok5ppi9ej,; ath experience?

  What force is needed to make an obje7uibda: d;.vc r:/aorct move in a circle?

  When an object experiences unif .);sbtx cvv;jkcfr7d ; o;co(orm circular motion, the direction of the net force x;ob; c; f. o;vct 7skcdj)vr(is

  A roller coaster car is on a track that forms a circular loop in the vertica8c 7b0j qt6xs87g:pvs+co iqv ;am2h ul plane. If the car is to just maintain contact with track at the top of the i80oj2 xa ;8vpt+ 7:cssu 6 v7bgmhcqqloop, 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 loopa4,.05gyp lgh (d i gzw*v0 jzj+b ejsuy)c5i. (radius = r) in the vertical plane. If cigy(zi+g*sw0j ,l hg5.je 5 jpv 0zb)uy4da.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-ci/bq6 m)0kpcgwq.qchqb d, *; drcular arc until it is going straight up. m0,c bdwq* ;b6.qc)qhq/kpdgJust 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 radius ho+/rjb ;yqkfs gt671 $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radius akpcjg 5x ii(far-(t:lv4n6) d2g+ez r at a constant speed v. Then it goes around the same curve at half of the original s(dlk nez:ic5v + g4(x)p -2arj fait6gpeed. 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 orrxyhmtj.16t ) .8 tmzh w-zq :vf1+nff radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared t:1 v 68qmxt fhz1m.f+.hnrr-ztwt jy) o the first?

  A car of mass m goes around a banked cus fxue v/;-r-hrve 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 car from the road is f;hex u--r/vs equal in magnitude to

  Two horizontal curves on p xn( )ka1 aguvo wc/62j/(xn6l.jn1qtmr 4kja 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)pq.wa /nj6/ covx2(jn4kn lxk(r61 gmu)ta1 j 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 br 8* tze(kg9 ilnta3+dobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionall3(*etzkadtnl8igr + 9y "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 to have b hede(l7 y7/qvoth centripetale7e dqlh( yv7/ and tangential acceleration?

  The gravitational force between two objects is proportional . sa;xze9g, d+o l8qjcto

  The gravitational force between 0 yojte n4eekbe9)g2j-fd +)p two objects is inversely proportional to

  Two objects attract each oiidc,v4z-t/m n8hj- buwt x; 8ther gravitationally. If the distance between their centersj m8cih / n ;-zxdwv-u84i,ttb is cut in half, the gravitational force

  Two objects, with masses ekp e3gi:9hot7 sn;e*$m_{1}$ 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 mas2j/t .*j.zrwst cdtp* 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 universal grav7f)91o2nu9dzs c eubo1 e 8ovqitation.

  Compared to its mass on thy 6 .r88lhfiyse Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth we*+ p:a4lb ptg76 kzmlhat it is on Earth. An object of mas7kle4a+ 6pg b mptzl*:s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves awaycr :0f8l6d-obl 8 ikea from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. nthso9+m/6x :y)q2gdm0 o bwd At what point is it beyond the pull of Earth':xb09h2+ogm wqdm/)6tnys d o s gravity?

  Suppose a satellite were orbiting the Earth just above the secl4a x15) etyig z24h4pz u.kurface. What is its cepzazgc)xyuth5142. e 4k i4lentripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radiyvi:-qy(v; tb9mw( 1qwic)ki us of twice that of the Earth. What is the acceleration due to gravity on the planet in terms ow(y9kw(ibq yim) ;:cq-it v1v f g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it zq6*u nnz*5dp is on Earth. The radius of thepz* zn*d n6q5u 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, uxx)3vi j6., lh qc+agbut planet B has twice the radius of planet A. If planet A has l. 3x, 6v) qjg+achxiumass m, what is the mass of planet B?

  Two planets have the same surface gravityv,2m5m)p5) fe 9 skntamyz7ik, but planet B has twice the mass of planet A. If planet A has radips n,a2vm)9kz5e 7t )ymkm5ifus r, what is the radius of planet B?

  Consider a small satellite mo2g*+ ;( ( la87 xwuvzx9vidvwvh/fwvfving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's +vdv* v/ 7u(f8wwvz2 x a(igvlfh 9x;worbital velocity?

  Satellite A has twice the magxz.0-fj1p;zg-4ub g:n5h-nb nitx o ss of satellite B, and rotates in the same orbit. Compare the two satellite's speedsgu4j5p: zbnngn-oxbz0xi g ;hf t-.1-.

  A person is standing on a scale in+a t2j -mvksa9lvy3 twj 7ruyx4h644z an elevator accelerating downward. Compare the r3y 6mkyrjv4 9tvwlus+7xta-44ja2 zh eading on the scale to the person's true weight.

  Who was the first person to re .vc( qa c/fi0t5+uwuoalize that the planets move in elliptical paths around the Sun?0w/+c tq(u5aov. fcui

  The speed of Halley's Comet, whih kr n-7zh ppc) kn/1se67xrv)le traveling in its elliptical orbit around the Sunnx- z /6kc7r 17shnp)hrp)vek,

  Let the average orbital radius of a planet be R. Let the / hy1v(t(vyw )k hykc-orbital period be T. What quantity isc (/vyhyvk1hwy)kt -( constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witvq6ht5id3u )n h the same orbital diameter as the Eaqi)56v ntd3hurth 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 "astronomicd v-be:vn9e+. u 2*v,qdzu dzval unit" (AU). An asteroid orbits v 2dz-vdneu*b+edq .9uv,z :vthe Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ry o spt;bwg eju-i-- /onz2./

  List the four fundamental foraxyu69)nki k k 7bhfa/t/;.xbces in nature.

  An object moves with a constant speed of 30 m/s on q :-m c*ftiuu(g7ah*q a circular track of radius 150 m. What is the accelera u fqu:* mcqag7(*-tihtion of the object?

  The maximum speed around a e/.-aaxh6n flb 55jt slevel curve is 30.0 km/h. What is the maximum speed around a curve with ta .j/b xe-sf565ahln twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle 8ykr+2va)uxmm,co6b wheel of diameter 70 cm when the bikco,k8bayu)mrx v2+6me is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axiszk+ ,a1sybuib,v *h x8:zdqa0. What is the cz0 ,8xs +avz,b* q :u1hkdbyiaentripetal acceleration?

  How many revolutions per minute mustp(wsl 6+1 wcbna2.xjcw 8 vsr; a circular, rotating space station of radius 1000 m rotat jbl8c s1 ww6s wxnc2ap.+v;r(e to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. c.vxxsyd e:ndwo3+ c0 (6pa0c It goes around a 13.7 m radius turn at 96.5 km/h.+d6 0:cscen cda0(x.x w3vypo What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The pign* mx7fytu;v i9 )hpr0(1lsystem is whirled in a fhy*mxtr) (plgpnu0 79vi;1ihorizontal 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 strong fo5b li5c, 9gwstring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 ti i55owclg,f9bmes 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 jjf4:cka7m0r t6mj+q*i k k/l and whirled in a vertical circle of radius r. At the exact bottom t0lka4/m f7cm+ik6q jj* rk:jof 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 of7a1.9qh5w a5cupm *a0euon t f 4g when pulling out of the dive. What is the radius of curvature of the loop in wcf9 pau un.*ewt a5m5 a7qoh01hich the plane is flying?

  A pilot makes an outside vertical loop (in which the center of thd ff xdm)6e73 o d5r+rrfxl:dbi:5dt9e loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with x+e r:d9d frld5 67) fd5trb3ixfo: mdonly one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stanm1jbn / v4)zj/7em mqod is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a ve n7j4vzmm qj1e)b/m/ ortical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizoy+l sw1)rs w,k k:nu3mfg yu,:ntal 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 olmukw,y1 3n :k+s:g sr)wyf u,f friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m w hlyw5pa )r1 k8rw)d/hg8o1em ith a speed of 20 m/s. The centripetal force provided by ham)/r81dygoe )hwl k8rw51pfriction 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 9:as 5l27+jse ws zgvcmust be the mini9 sezv ja7:sslg2w5+cmum 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. g n miv tcpm4tzj54c9uqulsv7 /717b, The coefficient of friction between the tires and the road is 0.pzgu7i77bv4/ c1ctm5tjm ls94 vq ,un40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to ne xfw:a;(8ofv os5g5 pvgotiate a 100-m radius turn at 35 m/s without skidvfvwpf;5a :g (x5 8oosding? (Ignore friction.)

  A horizontal curve on x.qtuj,z7i (x3u 40tsoio0bv a 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 raf: x9v9ey/ yezdius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankexh./bfdlcc 8./qi iomu+un:8d 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 revolvinggskx;xm u to,o(,+a k 9+/bkoz uniformly in a horizontal circax+mg(bo;kkzox, kt u/s+9o ,le 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 raceg m-c iq9+)siw;u (rbb car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m9 )ciu-b+(;igwb qm sr. (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 :d 6jz,5dsiin 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 Eask-ze9p 7jeu+ rth, due to the Moon? The mass of the Mo+euz-9 jek7 spon 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 i tw:dqpb,66pg s F. If the masses are movptdgq 6w,p6b:ed to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what d,pd6a zcb3e19b;o1sn / hhwz-yd i6m distance from the Earth will the gravitational forces duhd/ezymhdw-9a p dbn1 3b16is; o6 ,zce 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 i8 amk;3jiht4m s $7.4 \times 10^{22} \; kg$ 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 distanh2dy5wgn)jgoq 5 /;bdbvuk :) ce above the Earth equal to the radius of the Earth. What is her acceleration due to q/d5k:gb)5v ) ondhu2wb;g jygravity?

  The radius of the Earth is R. At what distance above the Earth's surface w: booat ejbre)a3 ;8t8ill the acceleration of gravit; 388 atb e:t)rjeboaoy be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its s *u5g9da c0p (.i 6cxn2)qwc rrp/zpynurface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as com *gqd crppz 9nwa2u 6p5nc/r. ic)0x(ypared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's centern7 prngc.ev9lf5 x1r, , the acceleration of gravity ir71 . pcxlfen9 v,grn5s $32 \; m/s^2$. 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 radius/u/uwketnh k3p- +50 nur b4lqq.+dne r. If the object is raised q-ne0e+4th3nu/ u5wkd / l.qnukbp+r 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 8or 7v/(2d rxfqwqh1n4 g8- e/cs mnluperson change when he goes from sea level to an altitude eqq mrno wx8/c7ndvsf 241-gru(8l/hof 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 lpkjb/ bi)z+6point 3r above the Earth's surface. What is the satellite's weigp b+/z) jbi6klht?

  A spherically symmetric planet has four times 58wfbdp, o d -.g.xcrjthe Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the - g5.wdbf, jcr8.xo pdsurface of this planet?

  During a lunar eclipse, the Moon, Earth, alb)i1g/)s/-:yuyniqv gc ja 9nd Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a ma))qy9s1iv/ i/:cguj g a-ly bnss 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 Moot w)z9g-orjfq1 pkf7e5-v,k e n.
(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 ag b/qc8hqj-9 jbout the Earth (i.e., it just skims the surface of t8jbgc j/ -qqh9he 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., it just skims pv3 xq p59ppv; +m/b1l )kvidcthe surface of the px1v95 )vpc3 p/+iblvqp;kd mEarth). 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 ab0 v. 7je0gwqpyove the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of th0qw0gevj y7 p.e Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter oeen9i2gbsoc )-ar .e1f $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet u1*cziwv sou:x9;(w.byb9 2qalhb ( lwith 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 i lfdbm1f -k9enua9mss ,;4 us,n nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to comple n,l, akm49dfm s-be9su1u f;ste one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is + 7hkioa lc;;hy,c2xu *nnip)m0g i +g$7.78 \times 10^{11} \; m$ 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 ixi-n8jm 12jeSun once. What is the average distance from Jupiter to the Sun? (The distan2jii-nm8xe1 j ce from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)