Is it possible for an object moving with a constant speed h t2m:1a58 neohn/z7i*vmfp 2zxb db8to accelerate? Explaine8xbh*m/ at2biz 1v:n n872f domz5p h.

  Consider a particle moving with constant speed such that its accen(lm ,m5) nhbs0lyb)wo e59r ileration of constant magnitude is always perpendicular to its veloy)sbr,9 m0nw5lo )mbi 5 (nhelcity.

  An object moves in a circular path at a constant speed. Co5c2f6eafrf)bls5 f/hmpare the direction of the object's velocity and accelerat5 2rh a)bfflf ce/f56sion vectors.

  When an object experiences uniform circular motion, e,3p v y1,dhxlthe direction of the acceleration1hl ,yed, p3vx is

  Consider a particle moving with constant speed such that its acb 1v)0rt eeg6q(iqfh .-ogm5dceleration of constan d1i0hg( m6-vfeqqe5)o rgbt.t magnitude is always perpendicular to its velocity.

  What type of acceleration does /xvrle4tll26r45ch kg;y2age otn + 4an object moving with constant speed in a circular path experienccx4y reo+g5vltl44 a/2 6t enh;2lkrge?

  What force is needed to make an object movuiver +92g;ye 7ai: ofn 1r9uie in a circle?

  When an object experiew-b7ey18hfugoi5 )e ynces uniform circular motion, the direction of the net force iso8wf-5i yhge)1 ybu7e

  A roller coaster car is on zn:9ln3 ojws 6a track that forms a circular 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 acceleration at tzl :j6n9nows 3his point?

  A roller coaster car (mass = M) is on a track that forms a circular l skp.)c 0ka/ fo6 wq6d3lbl3uroop (radius = 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 mi3ok 6.p63lbfkw 0d)lcrsuqa /nimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it is gorz8*wb5md8y: q-u ltq ing s5u*q lwmzq-8t yd:r8btraight up. Just as the 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 zu50hk,h:ys8goy b3i5 + upfj 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.l0)psxtl bkfj/.60dn:8 e6 7e v sdfqj Then it goes around the same curve at dq.k60npjs v e d:xt87f j/0bsf6lle)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 s1nth7q )p;im1gbz wi p/*o8 0nr-m ifradius r at a constant speed v. Then it goes around a curve of radius7npi8)m;b/i-w0q1o *tgpi1sfzr h mn 2r at speed 2v. 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 a 54;gcz-cy2cx s6njx 24gqg sdround a banked curve of radius r with speed v. If the road is frictionless due to ice, the car ca 65cs;x42gcjz42x sgc g d-qynn 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 bobs+t (lovp ghbawx6);1u9)zdf dled run are 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 f 6p; tg l+dd(h1bozvx)wua9)smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the kubuju/ak,xm . 0q;q3Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled teaxkqu0;b a uq jkm,3.u/m will intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an olap4,l90xh h rd1 idh-m1z,gy bject moving around a circular path to have both centripetal and tangential ac1 x4d d i1lh agm,-pr90zlyh,hceleration?

  The gravitational force between txgl6ye8 a:6xyb 20lo iwo objects is proportional to

  The gravitational fok0(fvzl)w n 8mrce between two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance b -se,sx6e, uis7fvd4m 0qw fb2etween their ceimffs wxsq,,de6u24ev s b0-7 nters is cut in half, the gravitational force

  Two objects, with massesbnh l 7-b +mqhswy(5u.,we*my $m_{1}$ 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 shha9*b.g 5cy;*zlxl 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 unzh rbm.ay3e,::g xs0jxjl q 5;iversal gravitation.

  Compared to its mass on the Earth, the mass of an object onjga(9) aw)g5t9v4 vv s:b rfyj the Moon is

  The acceleration of gravic9+5dq)v yvg- qjj +nsty on the Moon is one-sixth what it is on Earth. An object of mas -n+qc+95vqjsjvdyg) s
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 wbldo.*1j1/m 3jfj + st8fiqnyeight

  A spaceship is traveling s(m;sqpa / 5mo-bas 4ato the Moon. At what point is it beyond the pull of Earthq p4m/aa bso -mssa5(;'s gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Wvab-x);m 9xd) s8 ljiihat is its cevb9x) jdx8; )a ismil-ntripetal acceleration?

  A hypothetical planet ha0fids;a6e1kg s a mass of half that 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 acceleratf1dk g 0ise;a6ion due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Eart lo4ebxw:hae 6l+) ++gmiwy *sh. The radius of the Moon is one-fourth that of the Earth. Wha wha6w: y*sige+ 4meb xllo+)+t is the Moon's mass compared to the Earth's?

  Two planets have the same surface *ngng-xuiq q r lyr /52:5st8tgravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mn5 x:i/8utts ng-q 5qg*lyrr2ass of planet B?

  Two planets have the same surface gravity, but planet B bq8zuf.y y m+k e2hp6z exmx8o::0g,fhas twice the mass of planet A. If planet A hbpy8+hz,z8. :f ek02yfomg :euxm 6xqas radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) ay9yz :v:a: ujp8w :lwmzty cu 543w6rcbout a spherical planet ptrz u5c aw6w: c8yzyjy u:mw4l:v:93 (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of sate mm;5aa0yf.pjrog / d2llite B, and rotates in the same orbit. Compare the two satellite's sprdyj;0pg m2 m.a5f /oaeeds.

  A person is standing on a scale in an elevator accelerating doe/3 4wwm i4vjywnward. Compare the reading on the scale to the person'sye/ j43mivww4 true weight.

  Who was the first person to reat9 rdu kgf5xgf-,v2l (lize that the planets move in elliptical paths aroundx ,f lgtgk- r92dfu5(v the Sun?

  The speed of Halley's Comet, while travelz.*(mfan: zet4ya )geing in its elliptical orbit around the .( ):nezayge*maf 4 tzSun,

  Let the average orbital radius of a planetds-h yj 3hsm 0c(z9wq(w8 ;lex be R. Let the orbital period be T. What quantity is constant for all planets orbiting the Sun9hsqjes 3 8xmhcd;(y-zwl(0w?

  A planet is discovered to orbit around a star in tyl96va pu9.apu/7kiz tl, t g*he galaxy Andromeda, with the same orbitptlu y/6 lu,a.vzat7gi9p9k* al 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 from the Earth to the Sun is define9yhdps 7; jc/xd as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. Whap j/sxd;9ych7t is the asteroid's average distance from the Sun?

State Kepler's laws.oz v5lhndp5m 7 mu;cp8h6kv(3

  List the four fundamv :76puiypvj4 ental forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of raditaz9ep t;hp 46qu- (krus 150 m. What is the acceleration of the o -4utpeq tzrap;(h96k bject?

  The maximum speed around a level curv1qe 7m* k*vtpme is 30.0 km/h. What is the maximum speed around a curve with twice the rakp 7qm1* etv*mdius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimetfkv 8mow 618fmer of a bicycle wheel of diameter 70 cm when the w o8v86f 1mfkmbike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the fjpae7 u4a,,daxis. What ifeup a7j,da,4 s the centripetal acceleration?

  How many revolutions per minlvm:l-+-halthgd 4 i5 ute must a circular, rotating space station of radius 1000 m rotate to produce an a -t+ vgmaidll 45l:h-hrtificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 2565 cjogvl z:,y0 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What gvj ,:lzc6y 5ois the centripetal force on the motorcycle?

  A 0.50-kg mass is attac6/ u,,nxa2ng. gkk3kzfs go i8hed 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 withstand is 350 uo/826, gnikfkzxsa n 3 g.gk,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 strinsydo 8y 9ax/,hr:fy, ng and whirled in a vertical circle of radius r. At the exact top of the ,y onsxfr8 ,hy/y9:ad 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 whirled in a vertze8 kel-nku*o nuapmi: b0): n8i+c*fical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weig-*pce8no8i n e0+* bl: u imnfkuaz:k)ht. The stone's speed at this point is given by

  A jet plane flying 600 z :b6oom,62u v7b 3mgbviy, qzm/s experiences an acceleration of 4g when pulling out of the dive. What is the radius omv3 b, m, 6oqzovuzygb2b67i :f curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the pk; ,kceg 7z3fh.o1otaq69mkloop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only onah mcp19;qe7o, 6zkgkf t.o3ke-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand f/yj,1xb o 1l,ps/kj sis about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, l1fys,1bjp/sko,/ xjcan tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal c bp+ dm+hk3) e6zzjwq-urve with the tires on the verge of slipping. How fast can th mezwk-hd+bq+3jzp)6is 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 cur5 unlem7o1je8o i:m8 wve of radius 50 m with a speed of 20 m/s. The centripetal force providuo8lmn ejwm1i5o e:8 7ed 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 a+,btfe1.txf 3 ixa+ qtt a speed of 14 m/s. What must be the minimum coefficient of frictioxti1 ,+ba+3.xte ffq tn between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curv* y ;99dm b6augbb9chle. The coefficient of friction between the tires a hu9ygacbd9* 9b;6bmlnd 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 bobs/omo)f* 40vbb yhk g;aled to negotiate a 100-m radius turn at 35 m/s without skiddgy/vafok 0bm4ho*;) b ing? (Ignore friction.)

  A horizontal curve on a bobsled vg(ae8kkv) s 0run 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 kl7q/+ ww8iegvk +jd1 of radius 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 exeip,+k1 8 ldat $45^{\circ}$. 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 a8ihqj58ecz :q string is revolving uniformly in a horizontal circle of radius 0.hq5c 8qj:ezi8 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 a uniform rat0jez w6kg84 ole to a speed of 45 m/s in 15 s, moving on a circular track of radiusegl k8 4ow0z6j 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 y1(-, )audbtyhvi z-ud t9 0adof 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 stacl l i, thc;sa;/qm*l8nding on the Earth, due to the/*ahlcl,im s;q8tl c; Moon? 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 bx ig j056s(8 tzxxru:petween two masses is F. If the masses are moved to half of their initial distance, what is grjsxpxzu tx8 05i:6( the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, aamhrvw 8x1t3 pu;/qw) qx: c*et what distance from the Earth will the gravitational forces due to the Sun and the Earth cuh cear)w31m q/ *pq 8:x;txwvancel?
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 naxgh6k 9q974 qq:e umis $7.4 \times 10^{22} \; kg$ 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 g1x2g j7btp(o ol64l ua "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her accelera4 lul6 1o 7xjtpgo2gb(tion due to gravity?

  The radius of the Earth is R. At what distance above the Earthtp(x 1a -) m*xnlrxhf3's surface will the act- lrf(p)x 31axhxn* mceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a donlq ; v;s;2jblrr/y8istance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity onlob;;s;nr8yv2qjl / r the surface of Mars, is

  At a distance of 14000 km from some planet's center, the iie 1,ho 4a. fk/lbzh(acceleration of gravity isaz/(f1i ,oh.el 4ki hb $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface oof4rs b; jnttjbf.anol+ 959(f the Earth. The Earth has radius r. If the object is raised;5+ ttb. n99ol4nbsaofj (rjf to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weig pg +uygwn,op ij4t;(g9bx/ n9ht of a 100-kg person change when he goes from sea level tg,i9( nugwopp9 nyg4/+ xjb t;o an altitude 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 aboe 8x q :*,xe4l3 k rh/)e8.cevukocxuive the Earth's surface. What is the sav4 u)h ilcec:x8kx.k*eqr 3u/ x,oee8tellite's weight?

  A spherically symmetric planet has four.tru yjg vrlh-892-hr times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much wourt h.r-2uvrj-g8 y9lhld it weigh on the surface of this planet?

  During a lunar eclipse, the Mxipfdr u8-82 rrttl1.oon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has t1.rri- durxf8tlp8 2a 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 mh5vl+a x5k1t-co cg/transported 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 orgx09 c01ysdmc bit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellitecmgs y1x0d0 9c? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the j ba; )rhg s9d-55 0m jrw*dew):dos drg9ztu4Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolutg5hjtr )bw;95 smsa -roz:dde9 0 wdrg*ud 4j)ion 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 surf 8o6ly9xswzk uys0-,jace of the Earth. It is observed to have xyluj 8 s-zy ks906,owa period 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,w)ur ebgha( 611d4dlj*vp3,xo q0 usv has an orbital 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 Jupt( d97m-zg fub0wwhq 9phjgl. )1 p5xsiter orbits 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 in nearly circular orbits. Moon A has orbital rad/c dncxu o+3t0ius r, and moon B has orbital radius 4r. Moon A takes 20 dayxo n/3+cctdu0 s to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i-vdo/ygwa b,0lehj kt;wn6.5-cooae1q +j0 ls $7.78 \times 10^{11} \; m$ 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 1 tfpjjt3,x (- sx5wz6jzt(v wa92hv9 p2 years to orbit the Sun once. What is the average vax(2w9tj tjz5v whpp6f9sx 3 jzt(-,distance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)