Is it possible for an objgc6iym6 ihqo-:yxxaj,c0 s9 *ect moving with a constant speed to accelerate? Explaia-,xq c6m:yxg jys6ii9c *oh0n.

  Consider a particle mod4s w4,jba s1,1zafvdving with constant speed such that its acceleration of constant magnitude is always perpendicular to d 1sw1sb,dzj4,f4 vaaits velocity.

  An object moves in a circular path at a constant speed. Compare the dqr.rve,g,dht,cqw*f5f pc , -irection of the object's velocity and accelerati,-,f.rq *rvcgh5q,ed pt ,fcwon vectors.

  When an object experiences uniform circular motion, the direction of the accele*/ vy1qpzq umk8m;g3zk65 oheration 5uvpe/ kykzoq3 16qz8 mghm *;is

  Consider a particle moving with constant spee4+kn3w biyu91gbj 5nm d such that its acceleration of constant magnitudew9nnj+my31 ub4ig5bk is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a circ5edl/(*p5 svile9e2 s zu9p lfular ppsl z ill5(fvs9ed92e5 p*eu/ath experience?

  What force is needed to make an oic 2r sxy0356x4 sepaubject move in a circle?

  When an object experiences uniform circular motion, the directionwe v 5pm;(.rlt of the net force .ltme(wv5p; r is

  A roller coaster car is on a track that forms a circular loop i gx68n6 ikhtcu.-e kx2n 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 centripkh-etxi c6x .u 8g2kn6etal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms8 a ;k0.vh5np-hxhczt a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the looxzc0t-va8k.h 5h;h pnp, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until 5 rrhodn; :mkcu-z y1:it is going straight up. Just as the plane is at its lowest p;ry knuomd:ch -5:zr1oint, 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 radiugj q5++yg ec,00vi zxms $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of8j yx 81io,qha radius r at a constant speed v. Then it goes around the same cuqijyx88,o1ha rve 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 time?

  A car goes around a curve of radius r at a constant speed v. l1 cksym188uq Then it goes around a curve of radius 2r at speed 2v. What is the cent s yquc8ml1k18ripetal 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 with speed v. If th v0,*3k( 1rl zkv8,cqqtsxo kge road is frictions8l* kx0 v(t,,q1rzkkg3v qco less 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 equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the syu/fdyao4ah7, i26 - j2kjqvrame angle, but one has twice the radius of the other. The qk-4v,67frd j oy/jy2i a2ahu 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 radius curve?

  The banking angle in a turn on the Olympic bobslkslzneq8xx;n h- ;tc7aqy*p 32 ws8n1ed track is not constant, but increases upward from the horizontal. Coming aroundz;xkspn q;w 72q 3hlc8t 1nxns-y8a*e 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 v8kx) ,x1wn:1tbc eu7 bsub1pobject moving around a circular path to have both centripetal and tangv:1 )bkb81u7snbx cw p t,ue1xential acceleration?

  The gravitational force betw5rnn(9t nahv3een two objects is proportional to

  The gravitational force between two objects is inversely pou-4m we 2 qpdt9.efh2roportional to

  Two objects attract each other gra2nj5-q ics2 n vc.z,vjvitationally. If the distance between their centers is cut in half, the gravitational jvz,jcv52- .c iqsn2n force

  Two objects, with maslc*x19a t n/kwses $m_{1}$ 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 mas 3+lpsv5x pcxjsj dj077,g3i bses $m_{1}$ 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/ )odq pr4mk8q gravitation.

  Compared to its mass on the Earthkop-ilt 8e:3)/ bn hig f2onw0, the mass of an object on the Moon is

  The acceleration of gravity on t :(,g jiz wyql0(l3cz3lir+ oqhe Moon is one-sixth what it is on Earth. An object zq :ol(z3qcrjwlii,30 gly(+ of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, qkw co-4wmm1hi3 k/.uthe rocket's weight

  A spaceship is traveling to the Moon. At what point is it ,v.6o-ckghwg0gwg4 x beyond the pull of Earth'vgw6goh,g0kc .x 4w g-s gravity?

  Suppose a satellite were orbiting the Earth just above the surfa+95os0tktcwdo 3 nf2 y cow :gp.s,t:d1;svey ce. What is its centripetal acceleratiot9vn2:dgo0.we1 pt sc 3 5fwtcs,+y:;dyk so on?

  A hypothetical planet has a mass of half that of the Earth and a radius vlgoq7san ,ls 10g/-yof twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the accelg1lng70/,y vlssqoa- eration due to gravity at the Earth?

  The acceleration of gravit h hisy0bo vv -tgd/.y0-wu-/f +oiw-ry on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared -/f+. otih0 ou -y-r0 /ywibhd-gwvsv to the Earth's?

  Two planets have the same surface gravity, but planet n5xps-z l.yg, eo4vc-B has twice the radius of planet A. If planet A has mass m, what is the mass of planet B4gvs -p 5ly,z-xno. ce?

  Two planets have the same surface gravit p,m8-7 rawzxiy, but planet B has twice the mass of planet A. If planet A hazi,w8m px-r a7s radius r, what is the radius of planet B?

  Consider a small satellite moving in a ci6,t3klzeldu9exmw9 4h m j /a) zu8e0prcular orbit (radius r) about a spherical planet (mass M). Which expression 4dmuazx)lmhuw8 3p 0 e / j9t9eze,6klgives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. .cx:m t ztet(/Compare the two satellite's spe.zmce xtt/t:(eds.

  A person is standing on a scale in an elevator accan9qe rkj.8l,lr+da 0elerating downward. Compare the read q+ d9arlln,rkae0. 8jing on the scale to the person's true weight.

  Who was the first person to 8d+m8s/ xfayjrealize that the planets move in elliptical paths around theya8 jsmd8 x+/f Sun?

  The speed of Halley's Comet, while travelig 5(uqmz-kiv2v7e *dhs;e 6izng in its elliptical orbit around the Sunevqs-*e5(u 6 g7 h;i2ikmdz zv,

  Let the average orbital radius of a planet be R. Let the orbital periob:f7e+r mcezg94.rn ud be T. Wh me4freu7g+zrc b9.n:at quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit am(zn:l 5w5o.nj0gz wg round a star in the galaxy Andromeda, with the sa mnzoz55g w:n.wg (l0jme 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, compared to the Earth's orbital period?

  The average distance fr ,oc7aiz4n0 / trk3drbom the Earth to the Sun is defined as one "astronomical unit" (AU). An astero3k7c r,td a/zboin04rid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. ut54u qtwm;rw 7(sr9u

  List the four fundamental foru yg71m.upz8: .evixhces in nature.

  An object moves with a constant speed ofb1o h.fer+ wk, 30 m/s on a circular track of radius 150 m. Wha,r.w+e 1bokf ht is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. og- u ,de3al;lWhat is the maximum speed around a curve with twice the radius? (Assume all other factors remaiueol;l3,a -dg n unchanged.)

  What is the centripetal dth6ol/ d td g8kw0(y4)3xbe bacceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is mtb(h/eb x)80wdlg6 k3otd y4doving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 x 1d-la:qgg3 fahfbl*7zd j 77m from the axis. What is dzh:lg d-g*73laxfj7ab71 fqthe centripetal acceleration?

  How many revolutions per minu., +bjiqnm0hp ,lwm( fte must a circular, rotating space station of radius.,ibf,m qwp+ j(0 mlnh 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes aedx1fh1t79 lc round a 13.7 m radius turn at 96.5 km/h. What is the centripetal forcct791 lf ed1xhe on the motorcycle?

  A 0.50-kg mass is attac61zltze l4qsa( k;,nwhed to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstaztnk;s, q 4(1z awe6llnd 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 whjwuv 7l70rd)v l co0prxw c5tjd( 8(i(irled in a vertical circle of radius r. At the exact top of the path t0d vi7 (vo(ptrxdj) c 078(lcr5ulwjwhe 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 attached tub 2nr9tl f9(zo a strong string and whirled in a vertical circle of radius r. At the exact bo9rlt nu9fb(2z ttom 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 jet plane flying 600 m/s experiez;oys-w rhza qe*7-lifz5t 74 vs d,z8nces an acceleration of 4g when pulling out of the dive. What is the radius of curvature o- o5slqs7- z8v hzreyzd;4w*a fzi,t7f the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which hbt8 y uxgw*6y)a8cq)the center of the loop is beneath him) of radius 3208x t)g)ch*8buyy6q aw0 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 seven times his weight. xa .6yv,-;l saawe(n k What is the minimum r,6;wkl.yxne(-vaa s aadius 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 curve with t1utzs3 ax,b:w*oo9 urhe tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of frictioo1z s9utrbw uo ,:3*axn between the car's tires and each road surface.)

  A car is negotiating a flat curvm0gie- :t-u9oh;pgpd iff7z 9g 6tjw6e of radius 50 m with a speed of 20 m/s. The centripetal force provided by fricwf o:-m0;jditgei96p-t u p7hfgzg69tion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiuhlth 4p/9sqc91 k-b6mqnzk)os 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and th6/)9s z91lkn p k bhth-o4cqmqe road for the car to make the turn?

  A car is moving with a constant speed v around a l a)+ *pqu+ynlyevel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum ra+nau)pq yy +l*dius of the curve if the car is to stay on the road?

  What minimum banking angle 7 odja; asdr*3 vkyj-,is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignodj*as;kd-r v ,a37jy ore friction.)

  A horizontal curve on a bobsled run is banke+ n4mf,j u0o.ebbxj g6d 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 j5m qodwc( bzlyt5uxd3+9-t 1f0r6xm at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80dmlnd:.1s.fpm5og1 pgl/u f- m 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 horizontal fcbh 9 tr 27nrzmz+y4z8k fh12circle of radiu y z zr+429nhhf821cb mktzfr7s 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, 0rf/oc a48yuga race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of raory c4 af/80gudius 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 u: ,att 2bfi9cproton 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 for.4 ezzmv .w-jfej/8h yce on a 70-kg person standing on the Earth, due to the Moon? Thehw j/8fze.v ze j4-ym. 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. If the masses are+sh:s;mn :m8rruj6vqn;,xf i moved to half of u6is,x;n:h; q+sm vrmf8:nrj their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towar d*h b-udvp; d+ mx w,85ix7kunrlls++d the Sun, at what distance from the Earth will the gravitational forces due to 87++-w+xhksx u b ;ddnldvl,mpu ir*5the 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 is 9*psxr :t72wghrpvv tn7d:r -$7.4 \times 10^{22} \; kg$ 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 fod*mteft 3e 7ku bp6gj2ed.cq;o/67wjr a "space-walk" at a distance above the Earth equal to the*d.jf/tg 3mcekto u bwj77qd;e662p e radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above 1(z lviy km5u6(q/+ruuj62te euz)buthe Earth's surface will the acceleration of gravity k+t1 (eu/um qlu(bvz2j6i) ze5 y6ruube $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surft * uaw*,3vhxog*f zj1ace equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the sufz*av*wtu j1ohg* x3,rface of Mars, is

  At a distance of 140002+hq ejx+x15b + ,;gs egejsgr km from some planet's center, the acceleration of gravity is j grgsgxe5j+2es bh1 +,+ e;qx$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on rb)-qnwuuzz5i;y w +7 the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surfacew;b5 -)r uzw u7iqzn+y, what is its weight?

  By how many newtons does the weight of a 100-kg person change wvv9*;o e m ml.p1qw.hvkigx(u8+h wu )hen he goes from sea level to an altitude of 5000 m? (The mean radiwgve+ mpl.u *hk8x1vv; u io qwm)(.h9us of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a po*5ldw bi8 ;afbfj:6wrint 3r above the Earth's surface. What is the satellite's 5w: i ljb8f6*dabf rw;weight?

  A spherically symmetric planet has four times the Earth's mass and twice its, q,vus4ts9 nxo 6fl8f radius. If a jar of peanut butter weighs 12 N on the surface of the Ea4,xs8of u vlts9fqn6,rth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun a9+ bqia7n w2q/lmzp-d ll lie on the same line, with the Earth between the Moon and -dw 2in qlza7bq9+pm /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 n-itb 4paq lu97 c;5wtto 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 (i.e., it just skims thevw- d3+)qjgy2l zark8 )lqgaj2v+8r-kwz y3dsurface 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.eu0czf ck*y w-3., it just skims the surface of the Earth). How long does it take to make one uczc* 3 -fykw0revolution 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 tkpdgm:j4bf ogt m0 .63he Earth. It is observed to have a perj t .bggkf:m0o d3pm46iod 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 orbitalxl u, gbha 88mdt-8s;o 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 plahjbd 1k76i(5g e-rx6 cxk8d (uwjk a/vnet 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 orbitsu4/a:.h:1a o+ 9qdxnj2z2d a uu qzlcu. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 daaqauc oda u zjuhq2z9./u:412l dn+x: ys to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ij4zd+jxv+l 0t s $7.78 \times 10^{11} \; m$ 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 ynl vwu/8e7 uke g4hf+u6px9x9 ears to orbit the Sun once. What is the average distance from Jupitkuh+ e4pguxe 89n/ vxwu7f6l9er to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)