Is it possible for an object moving witp69zg s j:ue9kh a constant speed to accelerate? Explain:kzs96 gpe9ju.

  Consider a particle moving with constant speed such that its acceleration of c/vth n wk3k8;constant magnitude is alw nk/;w vchtk83ays perpendicular to its velocity.

  An object moves in a circular path at a constant s3r gki .uja /b y;y,8t(-prkvspeed. Compare the direction of the object's velocibrkpv 3ut8 y,ky ;rg-si/a.j(ty and acceleration vectors.

  When an object experiences uniform circular motion, the direcajikfbwwq-l;17 () l ttion of the accelerawk1- 7l;q) ta(iblwfj tion is

  Consider a particle moving d w:x4/laep5o0xi gby v65g)d with constant speed such that its acceleration of constant magnitude is always perpendicular 5doi65gygpvd 4:a w/0)bxexl to its velocity.

  What type of acceleration do-gfaek5 *se )pes an object moving with constant speed in a circular pa a kp-e)*e5gfsth experience?

  What force is needed to make an object movej) i/ . 3gzn9epjkhx( c:o;xrh in a circle?

  When an object experiences uniform circular motion, the direction of the net fa2r*8c4vzlj-h biy x8.h0yaeory.eayzcx-2h0 abjv8 hli 8r*4ce is

  A roller coaster car is on a track that forms a circular lot0bm9k hii6v*umruk9i 2v s(;9topx 8op 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 centripetal acceleration at thu;02po6ix 9bu8km( 99str vk vt imih*is point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (radiux9j-f tvk0sq* s9f*tjxv-k q0s = 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 4 sl:4n xrtabu9tagyu il*a8g8;+az 5 semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force 8llyatb ag:sau*t+gn4ia4u8 59r x;zon 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 curvefq(0;q blh ml;my-a. n 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 speed v. Then+*4v,dns j:eed gumyam :l( z8 it goes around the same curve at half of the original speed. What is the centripetal forcyg u avmsl(,jee*znm4+ d:8d :e 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. Then it goes aro h7u;ep u6cc ;uhanb) /g5m;fbund a curve of radius 2r at speed 2v. What is the centripetal force onc/h6u )f ebum ;acg;7; nph5ub the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve ekhnh 7 jk*hlqtkj yz7(/ f74*of radius r with speed v. If the road is frictionless due to ice, the car canzh t 7j* qhl4n/y(k* hekkfj77 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 bobsled run ai zn/ 2*ae:bzwre 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 is v. What is the safe speed on the larger rwiz abz:n/2 *eadius curve?

  The banking angle in a turn nbq)p( :pfn 6hq ab-9won the Olympic bobsled 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 ou(6np: b- abf hwn9qpq)t of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to havog6b3:k px)9h 2y3:brpb cdqqe both centripetal and tangential :bg)6 px q3kdbo23c9yhqp:r bacceleration?

  The gravitational force between two objects is proportionj .5kvuzt 8js8 ;chh;val to

  The gravitational force between two objects is inversely: iovrp,tuld*u3(9tqs0t)a4iq cmrq ,g z0a) proportional to

  Two objects attract each other gravitationally. : 2r8y3g hs qm29xqxmgIf the distance between their centers qs8yrqgm2m x293hgx: is cut in half, the gravitational force

  Two objects, with massej2;daoakpz , ac ))wv4s $m_{1}$ 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 mas7 wz21j.z2sh9 vkbi gzses $m_{1}$ 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 univ.aigeb5 unqu,2 jcc09:yb jq,ersal gravitation.

  Compared to its mass on the Earth oqib j4960ukj:* nehz, the mass of an object on the Moon is

  The acceleration of gravity on thecdpa6a8p wa)u ;k,ue ) Moon is one-sixth what it is on Earth. An object of massp c ,a);wkepa 8u6au)d
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, tk;zlkd/: mby ne* ddriq672rs p+-t*the rocket's weight

  A spaceship is traveling to the Moon. At what pointdw mc )q 0(tdntwj49:w is it beyond the pull of Earth's :dqcd(9)w nww4tt j0m gravity?

  Suppose a satellite w7u q.ss1oynjj f-7;z aere orbiting the Earth just above the surface. What is its centripet .ozj 7qauf1n;sj y-7sal acceleration?

  A hypothetical planet has+:duq 2buifv2t3k2 tzn:o ::i8znt5 tlwtff6 a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due tokti 63i2tn:2 tbu:fu5vlt+:w8zf z d f2:toq n gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of grgo v-ltvq)3w y v:y6v)avity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. vy)wvt3 v6q: vgo)-yl What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, 3,y0flw(sit r hij 8mvhb,fh; 7c po1+but planet B has twice the radius of planet A. If planet A has mass m, what is the mass oflj3i1;wf,0(pcmo th yb8ih vhs,f7r+ planet B?

  Two planets have the same surfac (yvi7u i 0gsde.25lqee gravity, but planet B has twice the mass of planet A. If planet A has radius re2 v750i .(sye ldguiq, what is the radius of planet B?

  Consider a small satellite moving in a circular orbiz5s jelqlmjp 5g3 0ioe8;6 dp7t (radius r) about a spherical planet (mass M). Whj5 j im5de7;oqps0 e8ll6zg 3pich expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotat(mlul9e*7ucw wddt9 )es in the same orbit. Compare dw9etuc9uwm * )(d7llthe two satellite's speeds.

  A person is standing on a sbei0 )djmb t5+6cb beitu78i4cale in an elevator accelerating downward. Compare the reading on the scale to the person's trueib5b td876i+ubm i)bceet 0j4 weight.

  Who was the first person to realw n2 8-mo(v7 db/eyiakize that the planets move in elliptical paths around the Sun(d b/nk8o-w yiav em72?

  The speed of Halley's Comgw0i 22mepkzd8(+ph eet, while traveling in its elliptical orbit around the Sung 8(02ihe dwzem 2k+pp,

  Let the average orbital radius of a pqez kjsqbn ,719 pk+icp.su70lanet be R. Let the orbital period be T. What quantity is constant for all planets orbiting tb7zi10puqs keq ,p+kjs97cn.he Sun?

  A planet is discovered to orbit around a star in the gala9k1mv7+worhr xy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mkow+vh m79r1r ass 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 t.fnt2 0x +gaeg21ajn(qtiec :he Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in o+t jant:0 fn g1g(.c2xeie 2qane-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws./kshpq boe0 14

  List the four fundamqsj/ f fe zn -+2rnj(zcam-u59ental forces in nature.

  An object moves with a constant speed of 30 m/s 314e myv +wv-ftim)3dg72c9ahsifynon a circular track of radius 150 m. What is the accelerati-3wic79te sv1)y dah + 4nf3m2f vgiymon of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maxim*g0( q*ll cc ,jkc:amaum speed around a curve with *cc(m,q alc*ja 0lgk:twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal accel* *5sff8-mtdz/ : uydpzw2 cqxl k56vzeration of a point on the perimeter of a bicycle wheel 5dfzs-tzym 62vz5d c:p w ul8*fqx k*/of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 mr7 xw9wi7t2 8cjakz9 z from the axis. What is the centripetal ac8i at c77rz2kzw99jwxceleration?

  How many revolutions per minute must a circular, rotating space station of raj8/u 6vt yb pci5+8dsqdius 1000 m rotate to produce an artificial gravity of idq 6b yuv85/8cjt+ps$9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It mb8qk ne.pq,e*o;ws 2wv2l7k n7pyu4goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the mokkuq n2,w qo lbw4e.*2ny ;vpp 8s7me7torcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is w*hroq8a/q ;: :fbv htiu-vgt:hirled in a horizontal circularo q*-g:8rv/bthtu:q fih:a; v 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 string and whirled in 7yyu:wft+ swm o+kp06a vertical circle of radius 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 +m0 y7 t+wpku6oyfws :given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical ci j8iusl9yp2hq; b/ c7trcle 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 givpcl8iqsb7hu2 t ;j/ y9en by

  A jet plane flying 600 m/s experiences an accelerat1pcxje4mmy qkx-z 86j d+ ,k5oion of 4g when pulling out of the dive. What is the radius ofxep4 jmo6y+1q-jc zk 58md,kx curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the bftmn)+h /p 0+sb j0wploop is beneath him) of radius 3200 m. At the top of his loop he s h+wp0m+)tbj pb0nf/ 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 sev,36bqkraduq)uh f9 zu2so4(l i ye*4 ap f*q*hen times his weight. What is the msbealq*iz o 36 ufhpuy44ur**qd f(, 92qakh) inimum radius of curvature 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 radius horizontal curk 6wpx q0nt2)cve 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'sk0)tnc 6q2 xwp tires and each road surface.)

  A car is negotiating a flat curveiybu cj:5:rn 3zf: h) (l m)t*e6ygnkp of radius 50 m with a speed of 20 m/s. The centripetal foriynn le3f :6 k)ry:)um(tpzhg 5 c*j:bce 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 vlpn ysyc.nu*n2 5r+e l28.ttradius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires av*.5l22t t+en cls ryy nup8n.nd the road for the car to make the turn?

  A car is moving with a c-qpiocyq39 s +n.ytn.sc+zh a 5k07rxonstant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stayst p oksz57rn h+ i3 qy0c-anx+.q9yc. on the road?

  What minimum banking angle is required for an Olympic bobsled t o1v ivgyoy8px7,6k u9o negotiate a 100-m radius turn at 35 m/s without skyg6i1v97 vk, opy8o xuidding? (Ignore friction.)

  A horizontal curve o8zfqr5v.c o 4sn 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 radius 100 m, banke7ureu,+) 7 luf+ v7mofyt yq)p8 lr1jsd at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m r;-*cl:fpx++ (oufahmdl u z/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 unifo78cdv( mikj9 nrmly in a horizontal circle of radius 0.500jdmv (nc98k7i
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 unl8a,j -uynat6 iform rate to a speed of 45 m/s in 15 s, moving on a circular track oa,j uy6 t8ln-af 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 pv0) dlx+ke e pb+p8;zhbw1 ce,roton 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 giw6ldni9z6 *70-kg person standing on the Earth, due to the Moon6i* iw ngz6dl9? The mass of 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 force between two masses is F.5o,fdoet9q:j,c0 2i x mvkxb+ If the masses are mov,ox2ic ext9d, q+b fo0mjv:5ked to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth to r*+yp s6j6zd)kyp ww3ward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth c3)y6zjdy+wps* r6wkp ancel?
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 i*zd de:wfzt;0s $7.4 \times 10^{22} \; kg$ 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 Earth eql2p)k0v8-f apf+ rwsx ual to the radius of the Earth. Wha fv )prlaf -sw0x82+kpt is her acceleration due to gravity?

  The radius of the Earth is R. At what distance a5d/l:l;n vk*p(ja uat bove the Earth's surface will the acceleration of d (t;ua lp: a5*/vklnjgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its2p1c*km 9(v ajrp5vr3pai r9m surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared 35vpr9m kpvr p9a1icmj*(r2ato the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceler,u ,x1* amrd) /i7z ;lvsutyhtation of gravity isrxas ud/h; v,), lzttm1i7*yu $32 \; m/s^2$. 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 Earttvm)6 4yq j03n 0kexnea oxi01h. The Earth has radius r. If the txaj0qn40vn eim 6exk3)1oy0object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons wo3eu6 b++eh,yg .8wuisbd6rdoes the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (T 3+u,iyb.6wdegrh6uo+s e8wb he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellitejyd i5ic 0;ow4 of mass 100 kg is at a point 3r above the Earth's surface. What j50y;o4ic diw is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its rad ol eh)c1uive*)o/:dqius. If a jar of peanut butter weighs 12 N on the surface o:euod i1)oc/ hq*e)lvf the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, they: qo.u+b 7avt Moon, Earth, and Sun all lie on the same line, with the Earth betva+ u y7:.qobtween 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 tvyxnhe q.j0 4nsvey41:tjk07o 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 circtx.(h e:opu4 cpr(ad5 ular orbit about the Earth (i.e., it just skims the surface of the Earrext(h ud:(p.p4a co5 th). 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 c mt: v(p+9hn6 dl-4q ckj2tyenircular orbit about the Earth (i.e., it just skims the sut k9pe -tjvncn:4h ylq6( m+d2rface 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 to2ts *8cych* jhe Earth. It is observed to have a period of 89 min. What is the mass of tht8**c 2j ychose Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbitgozg(k 80(b --ebgpj5r*p ,o(m ebqoqal 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 the plane7 un;l+ttc :m1;cd b+u+aedcd t 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 Ahfq,1v08bz coco *,l x has orbital radius r, and moon B has orbit0b x oqfl1chvzoc,,8* al 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;oe7hxf5x c4 g2ad3 tts $7.78 \times 10^{11} \; m$ 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 year(- kh4fogep0oq tn )s0s to orbit the Sun once. What is the average distance from Jupiter to the Sun4pf)qog t00(nkh e o-s? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)