Is it possible for an object moving with a constant speed to accel:d 0x) x.q76gr3vplepmr7 tui y9lo,gerate? Explaino0 6t lildgp: xr p. exy9,7g)7uvq3rm.

  Consider a particle moving with constant speed sucv(xy:qh; .3qcz60qeazs s0m y+u1z hc h that its acceleration of constant magnitude is always perpendicula(0shuyq cz1+xzsc3q.;h m0ev y6qa z: r to its velocity.

  An object moves in a circular path at a constant speed. Compare the directi/hz, /j9y-xqt( gducyon of the object u y(jt h/qg,x9ycz-/d's velocity and acceleration vectors.

  When an object experiences uniform circular motion,p lg,g30 lmzb- the direction of the acceleration ib0m-zgpl g3,ls

  Consider a particle moving with constant speed such that its acv3 9 ;ahiv06/qt-gup e/.i k)rvbzjmlceleration of constant magnitude is always perpendicular to its vel;g9hb6/uzqt.-v el)3vipmi/j a v0krocity.

  What type of acceleration dk-vju/ 3uj0 rgoes an object moving with constant speed in a circular path exper-k/gvjju 0u3rience?

  What force is needed to make an object move in a circle,jam(ccd(a f a01s*x i?

  When an object experiences uniform circular motion, the m5rwy 5xcp..gdirection of the net force5 x wp.rgm5y.c is

  A roller coaster car is on a track that forms a circular , vjgf 68lpj9n6zr0xg 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 centripetal acceleratinvz fgj 9j68,x06plg ron at this point?

  A roller coaster car (mass = M) is on a track that forms a circ )cacd3t2o2w p wv h1aygx-, z.n9nic)ular loop (radius = r) in the vertical planea,iz.) at-w onyvpw31x2 2h 9cgncdc ). 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 semi-circular arc until it is k92a 7s e xmcs sd/68*ntbbnp4going straight up. Just as thk ntb4s*d2epx8sc7/sanb6 9m e 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 radi0: )cet- za*69snkhzssp:fe wus $r$ 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 it -iu vso;wrm r jo)ch/+n23u2f goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curver3oj-u 2hcovi/+ 2fn;r)s mwu for the second time, compared to the first time?

  A car goes around a curve of radius r at a cons6dctf+h)h . 2y8iw)zkh n/z1:eag vsltant speed v. Then it goes around a curve of radius 2r at speed nk2wv8hz + .))hif6 :cads et1zgy/hl2v. 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 with speed v. If the rofe(jjb 70/ uk a4gjxy6ad is friction(uye7 0xbjk4fa/j6j gless 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 r;ic6mw.r(k2g0u pm prun are banked at the same angle, but one has twice the radius of the other. The safrickp.r ( g6pmwum0;2 e 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 bobsled track u/p9e7z-q w6 sy-08 m1/ni cjmogsbvv is not constant, but incr g0yn m6/z u/pvvcsq1-bsw8-ij e7om9 eases upward from the horizontal. 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 pathin *i5i(n12ln-rjs yc to have both centripetal yni(52ncj *snii r1 -land tangential acceleration?

  The gravitational force between two objects is proportional ph/,14we cuyoto

  The gravitational force be (pqcxx q:d43 g,od.mctween two objects is inversely proportional to

  Two objects attract each other gravimmq7pb+vkw8m7f r/ d ,tationally. If the distance between their centers isq,kvwdpm7 bm/ mr7+f8 cut in half, the gravitational force

  Two objects, with masavft fqy 7;9a40cxvy4 ses $m_{1}$ 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 ma,no u ktyo1uj*uyj .02sses $m_{1}$ 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 gravitationmkvc5b- :aa gy8::eiz .

  Compared to its mass on the Earth, the mass of an object on the Mo7: 7qoe) 4t79ctgkpixvq3y mhon is

  The acceleration of gravity on the Moon is onq zh u2,02((fu/r mv2cm( jpvl+oi tune-sixth what it is on Earth. An obje2+vhr(t/0iumz((jp nuu2q m olv f, c2ct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface.8h ac q4nu*r1q h-a9,cjwmwe zbgj8 3, the rocket's weight

  A spaceship is traveling to the Moon. Atsqq )rk5-2he0xw*b* s fvyz5l what point is it beyond the pull of Earth's gravityh5e2) -sl*krv5zbxq*0qwsy f ?

  Suppose a satellite were orbiting the Earth just abu81ct gx :m:alove the surface. What is its centripetla cxu t:g18:mal acceleration?

  A hypothetical planet has a mass of half3nz(c z(h z0m-lls0 js that of the Earth and a radius of twice that of the Earth. What is (zsz0l0mnlzh3jc-(s the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it i3i/4 o34l a 7fyd ddotgf,vll)s on Earth. The radius of the Moon is one-fourth that of the Earth. What ddvdtl4io3 ,/f3gya)o7lf4lis the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice tqm 4 r22vlpt9q eqm9wyg8(ke2ry ub-0he radius of planet A. If planet A has mass m, e94(2rq 8 2pwygmlq20-ueqtm9kyv rb what is the mass of planet B?

  Two planets have the s8/q r /4azrn 1 e zw5psgkb2s;t1ewq9oame surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radg;2/w ar8e9k 5/ 1sr znwqps z1qobe4tius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) a s4v4.f6 ja 5o,mz4dmukf udn8bout a spherical planet (mass M). Which em844d a6fujfuovz ,k .m 45ndsxpression gives this satellite's orbital velocity?

  Satellite A has twice the mass of suj-l) 2anx8nccimz 52h 9) wcpatellite B, and rotates in the same orbit. Compare the two satelli9zc5 cxlnw)i2jph8 au) 2mnc-te's speeds.

  A person is standing on j4apevq0 +st( a scale in an elevator accelerating downward. Compare the readi( tjasv0+ qpe4ng on the scale to the person's true weight.

  Who was the first personynx x4tda jt6 1n48hj;e)1n hs6bx)x g to realize that the planets move in elliptical paths aroundx xhb t1n6 )jjhyxn) eg;41xdn8 sa4t6 the Sun?

  The speed of Halley's Comet,imu4bu+6h- zsd vy(- x while traveling in its elliptical orbit around the Sun,6uuvbi+dz-(m4 xyhs -

  Let the average orbital radius of a planet be R. Let the orbital pe2zd-n r k8u(,5u z14l40pe qmjhdot/lgd bdt0riod be T. What quantity is constant for all plannk04dtzdd pbt1dm( -04/el8q ,jz o5rul hug 2ets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witjk 4v7s14rsa th 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, compared to the Earth's orbitalkvt4ras74 1 sj period?

  The average distance from the Earth to the Sun is definel b.o li7xakcku1 4e+;d as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third ofu el47ck+il1.xbo; k a a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ih(l1p/wpa/es+ h485dm hvim

  List the four fundamental forces in natureht5;q:9ea ztspf x2a: .

  An object moves with a constant speed of 30 m/s ofy .uep50n:69qijlkj n a circular track of radius 150 m. What is the yp9nfji0k5.j 6eu:q l acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is thewl65obmzckr+ 0 :c 5vz maximum speed around a curve with twice the rad0w+ zzcr5v:k ml5oc6 bius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleravj+jp*+,h/ jropwb d*kku +0ntion of a point on the perimeter of a bicycle wheelp+,jhjo k /dupw+*r k+bn* v0j 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 loca4 fcsmab25. kuv4*k xoted 0.200 m from the axis. What is the centripetal accelesxukc* ak25ofm 4.v4b ration?

  How many revolutions per minute must a circular, rotating space stati kuid-tfq0h-3-vs ;/*bpdp d ton of radius 1000 m rotate to produce an artificial gravityt dp--i/qtb;ku -d3s*pfd v0h of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.5 2+a :k pw qf pf+0:j7schc;us7yabn8ikm/h. What is:fa+f sc b80ws ijp7+u apny; h2cq:7k the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The systex 32beqf.i;jhc *xfsf1q p51)p6+c f luidv f;m is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the mapvfflif* ij);cq+xuhd .xf ep516 bc;1 s3fq2ximum speed of the mass if the string is not to break?

  A stone, of mass m, is (yfw( a5s71 njlva kv,attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string yk nj5vw(aas vfl7,1 (is 3 times 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 and wha:e; ;y(dlj-0i7ddmr xys0yp x6b c,dirled in a vertical circle of radius r. At the exact bottom of the path the tensioy i6dp jxy(7ya;0-,;s brlde0mcx:ddn 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 expi/ wmvjjkwv j),y4;ias+,7xleriences an acceleration of 4g when pulling out of the dive. Whj)jivmwx,l,/; i4yk7+wsa j vat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop cwe om(sow:; nz,o/k(is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half :ws(o,wmc/oo; ( ne zkof his normal weight. How fast is he going?

  The maximum force a pilot can stand j5rk:(bs+x.p(.niok3lzw7 3n o lbrhis about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a s3l73inw ( ko+l5(n.bbkhp . zrs ro:jxpeed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve 1)ry4g azd/o kwith 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 tires and each road surfado) 4g yrz/1kace.)

  A car is negotiating a flat curve of radius 8j;l/wg1 j 7fpyvdaq350 m with a speed of 20 m/s. The centripetal fora/ 1 fjyd;lpv7j3q8 gwce 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. What must g q 2/gocdg:2yp nke1*be the minimum coefficient of friction begok:g*n2/gdcy q1pe2 tween 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 )*ohnh0 zp 0h0ce9gqo)ib;qsoefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to sqp ;hhe0b 0ih*9s0czg no o))qtay on the road?

  What minimum banking angle n)bhqax tav1,y37g .gis required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore a7x,t a.v gbgh3)1q nyfriction.)

  A horizontal curve on a bobsled run is baidp 7mk4v1hlx0i kp48 nked 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 radnvvr s+lnw 0k5cr34bay/7zo9 ius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m iszc nbom4t-j d2 +wq6f;(sd t-yj3p dw2 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 .k 3n(i-:1fhuixy91 omnt sdnhorizontal circle of radius 0.50- m1f.3(kninnsyo9 :xd1u h ti0
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 qktpp3dt 2 ) 8k9ast,t+mqt6hcar accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500p6 dqkh qs29tat 3,ttmt+8)pk 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 consi:zdfu2v8xyeu2, gq x: sts 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 gravitational force on a 70-kg person standing on the:sjtz ym0h4i 8 Earth, due to the Moon? The 48ijm sz0:thy 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.xqx f,. 4hlrmr/iva n:iu;jw),(g 5f g If the masses are moved to half of their initial di.(r ,54j gqnawvh l )i,fu :xfxi/rg;mstance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distan(do1mvhw2*k x4eix 7i) bg.w8nk 6kepce from the Earth will .bkon)iv *k6 ihmg17exwewkp x48d2(the gravitational 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 ijf 7enb)7 w; xfy9yez4sp/ o+fo/pg5as $7.4 \times 10^{22} \; kg$ 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 apmc0-ng /lf ex;vnl8 + "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gr/ f+0g;lpv cxnnl8 -meavity?

  The radius of the Earth is R. At what distgkd(enz 6e/b udi56x .s zear6d-:/hb ance above the Earth's surface will the acceleration of grag idnb5/h .uz dseebdk/e 6rz(:x6- 6avity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its spdim z *8w4b./cdlqd6urface equal to 3 times the radius of Mars. The acceleration of gravity*4/8c6dpdbi.mzq l w d of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from so6( c wu. 9h jwd/j)kha3q4v p1u:sdavwme planet's center, the acceleration of gravity9uw4 1chjj3)qdk(h 6vpw.ad :aw / vsu is $32 \; m/s^2$. 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. The5*f* k k/ytzv2 mfnz:f Earth has radius r. If the object is raised to a height of 3r above the Ea*ff* fk 5v:y/nzmt kz2rth's surface, what is its weight?

  By how many newtons does ee(e9d ngo43y tih4x6xij5.pthe weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth (ingxeij h.4e4d5exyp9t63 o is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mas6 571w)xyk hf uls-axgy87 ksgs 100 kg is at a point 3r above the Earth's yxg1g6xwh-k )l kysa 577f8u ssurface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass .+d d,5fxqowy and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it ,xyw 5.dfdq+o weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on k 75;2n elsyyiaq bz54the same line, with the Earth between the Moon and the Sun. The Moon hb aynlz5472y 5 qe;kisas 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 trangu zh3l0x.: w aqnzo/p1h6y :csported to 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 4cubl))tc0t jabout the Earth (i.e., it just skims the surface of the Earth). What is the speec0lu )4j)t bctd 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 r22( oi 1kqt-es7cnttthe surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radtrc1ei7 qok(t2 -2s tnius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surfac0h46-cuk6b r6xz+ya kjlyh p 86 lfod3e of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (hb6alx+c4dolykf zh36 pjku68 - 0r6yThe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbitalcas8( v57dcg: rvx,ywom5 c6j0vwo - mz:h.mn 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 ly o8e.-hb bo7q*kqc 6orbits the planet 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 jds+d: pep9: k:kdf0pin nearly circular orbits. Moon A has orbital radius r, and mof+j :kdek9:p0 d:ppds on B has orbital 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 ishx47,km zfxf+ l9rka),p *u ee $7.78 \times 10^{11} \; m$ 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 Sun onc/h (ci*k zt8cdzqn7+vr 9 akn1e. What is the average distance from Jupiter to the Sun? (The distance from the Ear dz9r+tqih (kc87nz*nk acv /1th to the Sun is $1.5 \times 10^{11} \; m$.)