Is it possible for an object moving with a constant speed-l2+q 7.3 m jbawkiurn+mro0f8lb f, m to accelerate? Explain frfkbmmml7urob, a0w-q2.l38 +jn+i.

  Consider a particle moving with constant speed such that its acceleration of co;xqqw0+wdsy )t3z+l c nstant magnitude is alwayx y+zq; )dwsqc3l+w0 ts perpendicular to its velocity.

  An object moves in a circu0 ey(+ esfkeral23i6ilar path at a constant speed. Compare the direction of the object's velocity and accelerel ik2f 3 si(0a+re6eyation vectors.

  When an object experiences uniform circular moti4u2nvx:zb p *vba-zi+ :u:himon, the direction of the acceleratio4 :u2iiv*:-hzbnz+: bp aux vmn is

  Consider a particle moving with constant speed such that ijf 4 )2qm8ddmkazma 6/ w/( :xacmyru*ts acceleration of constant magnitude is always perpendicul8)rw 4zcmxmjd a* /km6 (a:d/yua2fqm ar to its velocity.

  What type of acceleration does an object moving with constant spel hdrqq.87) qced in a circular pathc)8 dq 7qlqr.h experience?

  What force is needed to make an obje4c58zw -xggpm( p2qapda x 290alen4 tct move in a circle?

  When an object experiences unif2gm8 c::v j xybbk)/whorm circular motion, the direction of the net force is/gjv bhk:bc2)x yw:m 8

  A roller coaster car is on amh8 )x,d d-ymy track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of tmh)ydx,y8d-m he loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a tra+k/ ossu). r7rkdht; kck that forms a circular loop (radius;/7u ksr)ok. tsk+ hrd = 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 th (y,fo,fx qt;pen follows a semi-circular arc until it is going straight up. Just as the plane is , (,p fytqoxf;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 curv 5+wxla,e: m,6hefcov e 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 radiujhq7+k3gd- r is r at a constant speed v. Then 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 torkhq 3g-j 7+di the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goes a+b-qv t)o 8+ q t/tqsvv(w-z hhp1iu)cround a curve of radius 2r at speed 2v. What is the centripetal force on the cvz-ht8vq i uthp/)(q-t )wocbs +q+1 var as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If theb)mq2e0 *ftsw road is frictionless due to icef*0 m2wq)etbs , the car 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 bobsled run are banked at the same r4sv wqu3k)zf5 6tr z+angle, but one has twice the radius of the other. The safe speed (no friction nu)r 4 rq5zkfst+ 6w3zveeded 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 bob gj48do, bcw cv42t1 lowi2f1isled track is not constant, but increases upward from the horizontal. Coming around a turn, the 8dfv2og, tc41 i 1oc 2iwjlb4wbobsled 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 movdqxrrgg3i)l)ia9c 4 s qy0o*qvb/z38 ing around a circular path to have both centripetal and tangential accele)gql4x3 ibdi3r sa08 q yrvc*goqz/)9ration?

  The gravitational force bv:2 ejpkiruyjl* /r/*etween two objects is proportional to

  The gravitational force between two objects is inversely prop .mud*o/zr-yql)d j 1fortional to

  Two objects attract each other gravitationally. If the distats5 s9) u:omge6w) jagnce between their centers is c)eju: 5s tsm)o aw6gg9ut in half, the gravitational force

  Two objects, with masses o2,k j8sjcj9p $m_{1}$ 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 massesp1c:t r q-1biev,0j qwud z8w( $m_{1}$ 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 gravitati2 a4mst7+ s5pnyx +lqeon.

  Compared to its mass o 4gfghnmrdq a6-m9210ls dtl,c ,oa;wn the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it/bd;w;n )8tjkk dyf 6qknudi9s8a 2l/ is on Earth. An object k kfq8nd9 dj26;wn/ti)us;/al8y kb dof mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, /;bqrm, oqu2 bthe rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pufx.; oquii78bai a z*(ll of Earth';ix aa.* (i zoufi87qbs gravity?

  Suppose a satellite were orbiting the Earth just above theqvl1n 7hvcn1mv; 0zt, surface. What is its centripetal acceleratioz vv;hmnn1tq,71c l 0vn?

  A hypothetical planet has a mass of half tha4ln63apt/pkx1 *jcqr vh n (0it of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in (ipp4ah 6j/tqvnx1knrc 0 3l *terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on cq.7;mo8vykl mdj5v a.-6kef the Moon is one-sixth what it is on Earth. The radius o mv m7v;qcjek dy5oaf6l.k-. 8f the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the sd32mf7 igg0x came surface gravity, but planet B has twice the radius of planet A. If pla 27g0dxfmcg3inet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass ofpn4 bkpc:wmtx+w8x c3 * qq4h+ planet A. If planet A has radius r, what is the radius of planeth+cpb w+nwx4x :*q8 3m4ptkcq B?

  Consider a small satellite moving in a circular orbit (radz m8hu+l ;ypw7ius r) about a spherical planet (mass M). Which expression gives this satellite's orbital v8 +ymwh;luz 7pelocity?

  Satellite A has twice the mass o0ca5u-,x+oqb 7v; ce2v+dyz eznj 8ny f satellite B, and rotates in the same orbit. Compare the two satellite's speeds.;072vycczoae8u zq xy ,v -ed+ b+jnn5

  A person is standing on a scale in an elevator accelerating downwa g4lz3se1ggy;rd. Compare the reading on the scale to the person's true31elzgy;s gg4 weight.

  Who was the first person to realize that the planets move in iu/q z u(5 tgfl/8yfm)elliptical paths around the Sun?t/f/ufil5y 8 )gzu (mq

  The speed of Halley's Comet, while traveling in its elliptic/zfmq )(ae yb7vg,. qlal orbit around the Su,v(qa )y/7lfg.q emz bn,

  Let the average orbital radius of a planet be R. Let the orbi/do c2gbo3z:ic --n kr 5l+fqqtal period be T. What quantity is qdc+2/3fg:q-nroizl -b 5 ock constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the gala,1es; quft2 edxy 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, c1s2;dfq,etu eompared to the Earth's orbital period?

  The average distance from the Earth to the Sun 99hnt uu3 sdduzoscsnf7 6 .+;is defined as one "astronomical un6dshn ot9z. 7u;u+ u93sscfn dit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.8ka0 + ) -ocvso,ccaq .s6jhas r6nlc)

  List the four fundamental f/z)q ptcz-3nzn;yb5 horces in nature.

  An object moves with a constant speed of 30 m/s on a ci d/0ov lf96vmircular track of radius 150 m.6o/f dml9vvi0 What is the acceleration of the object?

  The maximum speed around a level curve is 30y.(zfe4 hk1e9xwbz- e.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other fac.xfwzk(4zy9 b 1-eheetors remain unchanged.)

  What is the centripetal acceleration of p q,cw lno i-2ct:hd3 q7ce.*,xy;zhga point on the perimeter of a bicycle wheel of diameter 70:o.ld*c32 qtw nc ,ihg;h cyeqzx-,p7 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.6 j:vfe 2tp91l)7mj7sst6 tnrr 2ufuz200 m from the axis. What is the centripetal accelerations7ntzrts)p 1 :rjuu6mf67jt lvfe2 92?

  How many revolutions per minute must a circular, r9wksl4ilu6 pw0)cu(notating space station of radius 1000 ui4c0wn)9wsp 6kl l(um rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m rad:t.(ga3vqe k oius turn at 96.5 km/h. Wa.kv :og3tq (ehat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whns:c 5padjj9 4irled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. Whajcsp 4jad5:n 9t 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 whirle9 w5r ghmc4v-sd in a vertical circle c g w45ms-vrh9of 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 given by

  A stone, of mass m, is attacheod2jgvuk:c8 s q9x8ys wbb1yw .+1 +vhd 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 point dxy1v8bw++v1.bs9 qsou hg: 8kjw2ycis given by

  A jet plane flying 600 m/s experien+b5cf c)i6yd2f:uq gbces an acceleration of 4g when pulling out of the dive. What is the radius of curvature of thgc dcb+ 6uyfi 2qbf:5)e loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the lr+sj 7n6vh, ptoop is beneathp6+ n7jvrhts, 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 vdq ihi6-;2; quxj6px can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilotxd2ivpq6q ; ;xjhi6 -u, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80n7a v79vapye+-m radius 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's ti97p+vv7 nyaaeres and each road surface.)

  A car is negotiating a flat curve of radius 50 m n1u, e wy+g 148pu isak7yfw+qwith a speed of 20 m/s. The centripetal force provided by friction +gy7w,ifq+ eu84swynu 11 ak pis $1.2 \times 10^{4} \; N$. 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. 3tvma gcf kklq*0, ;-j What must be the minimum coefficient omcj,0 f t l*qakkg-3v;f friction between the tires and the road for the car to make the turn?

  A car is moving with a consta w42v+l ad;fglnt speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the min4; dwfvg l+l2aimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobs r h2jt iv mif(61-kl 8fe(;u/mg4dijeled to negotiate a 100-m radius turn at 35 m/s without skidding? (Igno ( 1tv- me6umj;l(kfi gr i8dh/ji24efre friction.)

  A horizontal curve on a bobsled run is banked at a ,gpq q+gu3sge*b 83ug$45^{\circ}$ 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, bank jyl(a9o plz3zx,15nwed at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m ifaxdl-,x+3:w*k kouy s 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 strin4xf +z b9l0n s 3 cex765v-ndlszqan/rg is revolving uniformly in a horizontal circle of radius 0.50a x/7s0eln9z4r5-lqcb f+n ds 3 nxz6v0
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 cahdv - wc3h)-ypr accelerates at a uniform rate to a speed of 45 m/s in 15 s, movinp )-y3vwdh -chg 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 consis5b)kdl4c:oesgeaa1 c20owt p50hg 1its of 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 gravitational4*) m rstr0q*-:r wxvqp(qif c force on a 70-kg person standing on the Earth, due to the Moon? The mass of the 0-f *qrrirsvx wq)(* 4ptmc: qMoon 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 ar-mw* ik 0d bvab 0e6t-edl*yi)e moved to half of their initial disl0tevi6id* we-aym0d-* k )b btance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance f +j ;knf*chl*arom the Earth will the gravitational forces due to the Sun and the Eah*kn aclfj ;*+rth 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 Mooner +pj z*h0cj8zu2- sy is $7.4 \times 10^{22} \; kg$ 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 fk-zr.9hb cq 4 pdhii;+su8a e8or a "space-walk" at a distance above the Earth equal to bdisz-ur e49; + ckpihah q.88the radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what(uwd:tp 8p 2lej,w ,pm distance above the Earth's surface will the acceleration utl(:wpp , mjw p,8de2of gravity be $4.9 \; m/s^2$?

  A satellite encircles v 9vi 8:6jo */jd-r mjyk9bgnzMars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity ji8nomjgyd 9- vj6* z krvb/9:of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 kmvg hke,2x,i; d from some planet's center, the acceleration of gravity ishg,x ;e k,dv2i $32 \; m/s^2$. 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 radiu3+p usz:;qm dj vk6u-e(;tn jg/ jrl1ws r. If the object is raised to a height of 3r above the E :rksl;e63 -ujw/dn m;1uzjt(gqv+ pjarth's surface, what is its weight?

  By how many newtons does the weight oxp m/x,dqx.ye cl*x: )f a 100-kg person change when he goes from sea level to an a,lxp*e:x)my q cx./ xdltitude of 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 point 3r above the /i iitn,7vo:-f8 jcbv Earth's surface. What is the satellit7 njv,bico/-ftv: i8ie's weight?

  A spherically symmetric planet has four times the Earth's mass and tvjv6 89hfxuqf m q,16u3iwg7hm86q nhwice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would itw6 vqhh 9xfmm7hj 6 ifquq83vn8g,6 1u weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun y th8cxkg *r(vu8aoq(4jq8d l( 1ox-iall lie on the same line, with the Earth between the Moon and the c4 o( -8d1((iaxytrkhgl8x*qoqj uv8 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(vt - lkdk a:-u3(yg fsoqq;*t 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 ciwt :;enr+fkm 9059x oz6kihngrcular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of onkz9;0i5h+6nf9wr m xktge: 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 tnaauytdft. sj.f 5f.f5 (/zly t,r6ttgn;76whe surface of the Earth). How long does it take to make one revolutio56/r(.a..6a ;ttfy 5fywsfdg7 ntzltu,nj f tn around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular or;g,t dcjw8j *dyw*hh7bit 230 km above the surface of the Earth. It is observed to have a period of 89 min.8wcdhjd 7j, wg;h** yt 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 diameh+,(tsd cu9m tlsvc1 (ter 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 plan 6ejxwmgs89y ;et 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. Mo ;g-5h ,nhulqik fkg8:g zt1(oon A has orbital radius r, and moon B has orbital radius 4r. Mk 1fkqgi;hu,( o5:hg8tgnl- zoon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ibez-:l7+8zfxom xg o8s $7.78 \times 10^{11} \; m$ 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 0n l ehrz-l*:8-suxln to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The dista x:h-* -0nsuelznr8llnce from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)