Is it possible for an object moving with a constant speed to accelerate? Expl*tjp4: hcczjv zcg:e* a.w 1-eain.t-egp e1*wjz a* jc::zcvh4c.

  Consider a particle moving with constant speed such that its acceler(6tqf 2/c0 d(e toq 5a7pmlyqqation of constant magnitude is alwctf0ql e5(72am 6( /poyqtdqq ays perpendicular to its velocity.

  An object moves in a circular path at a consta1bkg5ikz b 1(f,feye 2/r2iyznt speed. Compare the direction of the object's velocity and acceleration vect(f/f y gi1 z byei12kkrez25,bors.

  When an object experiencn3-zop 3qy.qdiwe:edn2o 1 n* es uniform circular motion, the direction of the acceleratiy:wdqeoq 3ei.op z2 n3d*nn-1on is

  Consider a particle moving with constant,vy8;;m bi)tr9ut oh5yb+evv speed such that its acceleration of constant magnitude is always perpendicular to its velocitb8o+rtv);yybi; vtu, v9mhe 5y.

  What type of acceleration does an object moving bw5kr)dn6mtc 5 gaq2 ,n ,ved,with constant speed in a circular path expd5q5dt,mb enw 2,avg)nr6 ,kcerience?

  What force is needed to make an object move i, qft4;j,ig+n/tz8p kawiv7wn a circle?

  When an object experiences uniform circular motion, the direction of the net f 8ramb d xjr2w6k0eg.*u.d exdgj;x44orcmk be . xj2.jr8dx 46ggdrwa;e0u4*xde is

  A roller coaster car is on a track that forms a ci k :mtjscdvgd65u4u kif-9z:- rcular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what c sj -m4vd56 :kz- dg:fuukti9is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circ4/t0sz 8 0qdgm:oznwq ular loop (radius gz o/qs nmd80w0z:q4t = 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 vertical0ky ft;:eqf .y dive then follows a semi-circular arc until it is going straight up. Just as the plane is at it:y.ky t f0q;efs 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 radiu6g gpp ,50sculs $r$ 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 zp2+sd)4m z ax:ko51w chv k)+eer l1wspeed 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+l1ha ez5 xw d)4vmsezc:w pk+o1r2) k for the second time, compared to the first time?

  A car goes around a curve d hh3f7yab8xwrw-*0 a of 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 tf3 *bx7a dw-0a8hyw rhhe car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve oxax 3z9u(+fa1uefh 11ak sc 7nf 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 equal in magni+ ka1 ax7uxnsh3(af1 19uczf etude to

  Two horizontal curves on a bob/(1(l lgy oncmkk/;b, lzch.hsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to llg/h,kmc 1/ch.(yz k;(onb lstay 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 is not cowlr w8c :0;wsqv j*;yc;+ chtgnstant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," t+;w:wg j0s;;lc*8rt qwvcychhen go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circulep1zav ,/f8 u0ynhn(i ar path to have both centripetal and tangential aczf p/,(8 0 vhenyuni1aceleration?

  The gravitational force between two objects is proporn154b(3xvq pjhxdz e )4okhb-tional to

  The gravitational force between two objects imf28;l)j5ae .m he bnos inversely proportional to

  Two objects attract each other gravitationall 2e5rt gv-bh*06 )+lqyax4f ybog6tnhgb v/ .ly. If the distance between their centers is cut in halff t v+rgql-gola 0hhyyt b5xv /g2be).n*6 6b4, the gravitational force

  Two objects, with massegn frs4 0l;3k2chvf.rh e 08ees $m_{1}$ 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 maso9.4fhb)7ypcacp0 os 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 grag r)m 5eu7ys(y1ha:uuvitation.

  Compared to its mass on the c.x5 -dj cji5rEarth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon i:vjn9kjevb 883cf b 9ns one-sixth what it is on Earth. An objee9bnk fb8v9j j83 v:ncct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's + kem/l yj3ik91wp m/jweight

  A spaceship is traveling typ.-ff0 xh 5px(owv1 io the Moon. At what point is it beyond the pull of Earth's gravitw1pp0oi.h (vxff- 5y xy?

  Suppose a satellite were orbiting the Earth just above the surface. Whatwav6 51n fwl1 fekks/6 is its centripetal acck66 efw vs 1klafwn1/5eleration?

  A hypothetical planet has a mass of half thm65knsrrj t8 +kow 72uat of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the k 5+rm sn2roku j7t8w6acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. The rf 8c0d(dctup .l)oy21 6qwjio adius of the Moon is one-fourth that lyijc t qu2.wc1 6d)0(d opo8fof the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface g rug bcaqn3)+r -mbj/:ravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of a rcbuj-: )b+gr3n/qm planet B?

  Two planets have the same surface gravity, but planet Brc)hzge/u -m - has twice the mass of planet A. If planet A huegmch r --z/)as radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (rmy .79gz)h7zl0j(tii zhbk5o b 9txj8adius r) about a spherical planet (mass M). Which expression gives this satellite's orbitalb9m j.x i(8gjt0zhi5yzk b9 7ht)oz7 l velocity?

  Satellite A has twice the mass of satellite B, and rotav*xtf7 bv0*h ne oubo/fxg57kc 6 /2hgtes in the same orbit. Compare the two satellite'2f7t xn7g vb5u hh*06veoxk /b*/ocg fs speeds.

  A person is standing on a scale in an elevator accelerating downward.f6xe7jcu( *dneo. c pqu6-nz+ Compare the reading on the scale to the person's tr6.(jq 7updxc+f6 *cenunez o -ue weight.

  Who was the first person to realize that t1w ,::fmom+ sgt how5ul9*w bnhe planets move in elliptical paths around tow+l5n1g whm*smwf: 9u ,otb:he Sun?

  The speed of Halley's Comet, while traveling in its ellxudefr42(bx9/* sslt 0x:j uhiptical orbit around the Sunf(2xu *r 4sh et/ls9u d:0bjxx,

  Let the average orbital radius of a planet be R. Let the orbic qb,wxw(5ki *tal period be T. What quantity is constant for all planets orbiwkb, * w(5cqxiting the Sun?

  A planet is discovered to orbit around a star in thef8/5x+ruvka tyfy td6um0*.x galaxy Andromeda, with the same orbital diameter as the5 fxtyf/dtkm6 +rv*uau 8x0 .y 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 from the Earth to the Sun is defined as ccw,dk3 igt n h1q*p.fk-1i) qone "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. Whtn1kfi)d3qp*qck1 -c., hwi gat is the asteroid's average distance from the Sun?

State Kepler's laws./: at jw3;8jc uk/tc(k(o d*ylmvrq:g

  List the four fundamental forcespj kh-v/cw ,a. in nature.

  An object moves with a constant speed of.akqc3t pf0 ( qbbzj,h75eug6 g)(m xv 30 m/s on a circular track of radius 150 m. What is the acceleration of t tg(cjkv q 7m3 he),(u.pz5ba0qg b6fxhe object?

  The maximum speed around a level curve is 30.0 km/h. What is the4xp 59u u*srrh2khdsof;*d w) maximum speed arounds9rd 5kuxfs 2up*wh; dhr4*) o a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal accelccgdha7v3n-;u4ikg 9kkp -uwi* 8,vperation of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving3c98*uvdpp k i;c7wn,ugak4kv- h -gi 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. Whi7q 9(gsb viz; bgo:2rzyh3 (gat is the3:zbhgb(7ziiv(2g g; q osry9 centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station o n3 xg+08,rvjn. kwf7(coae/esvm -kqwfe82 yf radius 1000 m rotate to produce an artificial gravi7(sejqmy03+ofv.kfg-vx8/e n a8c wr2wn k ,ety of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes arounf( qj,+prpkly -s, g2md a 13.7 m radius turn at 96.5 km/h. What(lrpfsk ,+p m,gq2jy- is the centripetal force on the motorcycle?

  A 0.50-kg mass is attache 8 :v p:d*2: guztueq.gmnhjk-d to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximn2q8gkhv: zupgejd*: : .utm-um 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 atte7 v/sdvt/p(e ached to a strong string and whirled in a vertical circle of radius r. At the exact top of th// p(sveev7d te 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 attached to a strong string and wh ym3 :o.chg* y 4/4auketgc0rpirled 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 is u4y0cech .a/ 3pkg:4 mtro g*ygiven by

  A jet plane flying 600 m/s experiences an accelerat xur8tptc5l z56)kyy 4ion of 4g when pulling out of the dive. What is th5zy) r4cu6x tp5k lt8ye radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center dm;:j8g ycv2 ,z d+zatof the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with on,a2ygvt;:dz +8 cdmjzly one-half of his normal weight. How fast is he going?

  The maximum force a pilo /lpopv xtd/m,vtstadp gpn34 +.*f56fep*j 3t can stand is 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 speed of 250 m/s5vp/,px3j t4sdt*p/ne6 godf3mapl t*fv +p.?

  A car traveling 20 m/s rounds an 80-m radius horiwp 1 +zln-r)okshgk ,8)t t1nczontal curve with the tires on the verge of slp k,c tzstkg- n1))+1rh wnol8ipping. 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 surface.)

  A car is negotiating a flat curve of r6fa qpmb4ha80 69:b twuw6gn fadius 50 m with a speed of 20 m/s. The centripetal force provided by frictiow66p9fa hgaum tb648bf0wn :qn 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. ;yx +2,q7nqp(*oaxvrh zp)fa What must be the minimum coefficient of friction between the tires and the road for the ,oq*xx)zyapf n7a+rq v2 (h;pcar to make the turn?

  A car is moving with a constant speed v around a level curve. The ck9cte 3j/j ugew,+ wv3oefficient of fric/+uj 93weg,et3kcj wvtion between the tires and the road is 0.40. 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 ne9:gsbq9*lkjf* cnx n (gotiate a 100-m radius turn at 35 m/s without skidding? (*nlx 9n9jqb( kc:f*sgIgnore friction.)

  A horizontal curve on a bobsled run is banke21wfdn,n sc h9uxtf,z:+d+l od 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 rg-( 6wo h0pioym 0:e;*hqlrocadius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked aah1kqy ig4 03yt $45^{\circ}$. 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 unktj54 cwqrt5l75w k/wiformly in a horizontal circle of radius 0k t7/ 55lkrwwjtqcw45.500
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 race car accelerates at (3ribcor4yqa.c3 wd:.x .lk02hzy ke a uniform rate to a speed of 45 m/s in 15 s, moving on a circulaor0 w3hc.c q ir2ya kx.y(.:zb 3lked4r 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 consists vq6g/m .tw6mp3z:v r cof 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 stand3 0bp +36r8j xwv 6ngo ggy8)a/bhuemeing on the Earth, due to the Moon? The mass of the Moxy3g en omp/ + 8u 8h6egjg03vbr6awb)on is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attrc1;6ypj1 mrez active force between two masses is F. If the masses are moved pm;1c16 jyezrto half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towars*(os6fi po5y ckgz g(30oab-d the Sun, at what distance from the E3zo6psgoof50kyg s (* c-ab (iarth will 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 isi rl5f4wvf iok( +kb) 44v8lesfn0ch9 $7.4 \times 10^{22} \; kg$ 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;ou*e wkw35 hdtn m77x 6dija4 the Earth equal to the radius of the Ead46h5*3xamdkei; to j nw7u 7wrth. What is her acceleration due to gravity?

  The radius of the Earth is R.e -gm7:62z9p0klt noe:s q zgz At what distance above the Earth's surface will the acceleration ofqee0mzsp6 z 7n -kz 9g2t:g:ol gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal trfp5f4 e/hr 8xo 3 times the radius of Mars. The acceleration of gravitp 84/r5rxhff ey of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gravityt4kbc9)3o(v g3oy 2ui3v hmyh is(yc m)v2o3ovhu 3gb4yh9it3 k $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N mp*0u/3wt t dwn 2vto;on the surface of the Earth. The Earth has radius r. If the object is raittww/ t2 d0np u3*o;vmsed to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1006heon:g.5 wuy s+coc6-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of e + u6 o:c6ngohy5wsc.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 Ep 8sc*unaky kxp( kpo +0*lh7a.0p6ryarth's surface. What is s00 6*axp+pku rky(l 8apoc p*7 h.knythe satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice itshe0( +t/)hkj ce ctxw) radius.+h kc0()xet /j t)hcwe If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, witkc;vo ogu( x(;5spfn+h the Earth between th(g5+ koo(cxfs;n ;p vue 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 t7x: nphch 8zw1fj2 (xto 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 justczny u,o m;r2qay428z*9tbyo skims the surface of the Earth). What 9z8m*ay4 nqz2o2ob;rc,yu ty 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 th 92.zisms0qucai d/ vaft;1rg-gy* l -e Earth (i.e., it just skims the surface of the Earth). How long does it take to-s;iu-qclzmrft2 19gi ga v.a s0*dy/ 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 thds1;ct0kgt.k. pi15cp;l 9 yrdr 0 qeoe 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 the Ep;1k t1s po kl;d.9r 5cceyt 0diq.r0garth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an or2 us-rvqs0cct)m 9 6jm2i)hds bital 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 *b 9uteimwa0epcm *dm*u4s9- 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 in nearly circe4o6s( a0ar bikfx6. hular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 (.si ab4r0 ef xkoah66days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is c0rieq0;fiv f aulw 0l+/9a(n $7.78 \times 10^{11} \; m$ 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 onw5kd*ujhyqd jh4g0 s 52.m3ezce. What is the average distance from Jupiter to the Sun? (The d.0*qwd4 3 g dj5mz2skhhyeuj5istance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)