Is it possible for an object movi ) cller/8 gqz52wtp:bng with a constant speed to accelerate? Explain2)p l 8 /e:zrlgq5wtcb.

  Consider a particle moving with constant speed such that its accelerat78 un:g2eg/a sn+ d;cpkyizihj5,a6pion of constant magnitude e7i p5g;/n8juainc syza +gpkh,6: d2is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare ther) ir*e*q-3rr.z wd) (naamzp direction of the object's velocityarqz) * rwrem3r .pa()d-n*zi and acceleration vectors.

  When an object experiences uniform circular motion, the directkq::;kv4m i idion of the accelera:km;q 4:di vkition is

  Consider a particle moving with constant speed such that iq.t p*mc3kk+s;0 br n s(xorn5 (xt7hvts acceleration of constant magnitude is always perpendicular t n.rx+qtbh;t(nv s5o 73(0 pkkxrs*cmo its velocity.

  What type of acceleration does an obje9rxtv 9 dj.:mhl+hv9q ct moving with constant speed in a circular path expervqr9h99 v.lj:+t xdhmience?

  What force is needed to make an object move in a cir3cil,6v+boq7, xb ho-d qfvi5j5.dz ncle?

  When an object experiences uniform circular motion, the direction of the n9;oky0 itj 0jtet force00j;t ikt9 joy is

  A roller coaster car is on a track that forms a circul/+ bu5 -y5wd83;thioiq4p b wggvwns.ar 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 tqb-go3wn 485uh+;i5wtsb ypw /g.ivd his point?

  A roller coaster car (mass =b5 g 2x5 1uzrc0/fvxjq M) is on a track that forms 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 loop, what is the mini f5x2x0zrjq/v51cug b mum value for its speed at that point?

  A pilot executes a vertical dive then follows ,i5aui uq/.uk w-v:owa semi-circular arc until it is going straight up. Just as the plane :v,qauu wku.io 5i- w/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 radius/9qqdv dp futw2i:pw65:3k ck $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of cyrn/+sf//ew olgc(,o3nyo.5v5 i gwradius 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 goesc5lg ne /vyi+( gof.c o y/w/r,3wn5os around the curve for the second time, compared to the first time?

  A car goes around a curveajhb izcx+moi()mow;8 l 344f of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the oh cf3+ia(mo); iz84b4xmwj lcentripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around rbnq91 p q, 7h kmu0td/3ltix;a banked curve of radius r with speed v. If the road is frictionlh,0; 7dbqkitrq3 nt9p/u1lxmess 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 fhxt qh32p e vqv9d *9hov622iat the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the*thv 9xvd3 9hefvph2i2qq o26 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 constant, but in4r4qrk*;,n 0dt5a1y opw fre dcreases upward from the horizontal. Coming aroytdr*do,; 5 q4k4rep f1w0arn und 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 path to l o0s-,/epgtsqn7 h+ehave both centripetal and tangential acceleration7nlhq-+ts0e,/o gep s?

  The gravitational force between two objects is pro8stq k.0tm:khb ,-e afportional to

  The gravitational forcety8w khn--s 02yh,gve between two objects is inversely proportional to

  Two objects attract each other gravie ycmo4w44)7x4nim wetationally. If the distance between their cex44ewi7w)cy4en 4mmonters is cut in half, the gravitational force

  Two objects, with massesotdn h a*r00(sb iqp5- $m_{1}$ 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 mass.7ep-au b+ .mav1vq ures $m_{1}$ 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 un /4 g/tbyrwfe0iversal gravitation.

  Compared to its mass on the 5h m,j fq+, dtmqb yt-hl4(9vzEarth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth wh 56ll-jwgn/kp nxtx 74at it is on Earth. An objec5n7 xn-w glk6xtl pj4/t of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earthriui +mj:q3i 3j+ti:s 's surface, the rocket's weight

  A spaceship is traveling to the Mg( gc8bvw)ov6i7 -lknoon. At what point is it beyond the pull of Earth's 7)i8 gblg (ov6vw-nkc gravity?

  Suppose a satellite were orbiting the Eart8 cd-, +cgwwwvh just above the surface. What is its centripetal ac w-c v8g+wd,cwceleration?

  A hypothetical planet has a mass of half that of the Earth and a rad*;mmim/* d elaw3sd 92j mx4bzk0ntu,ius of twice that of the Earth. What is the acceleration due to gravity oi0l 2u3enadbsd/,tmwmz k m*x*;j94mn the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Mos,n/jvwxt mw4b 9z i/)on is one-sixth what it is on Earth. The radius of the Moon is one-f/wixb t)nm /4s,zvwj9ourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, 9u1:rl j;bi dsbut planet B has twice the radius of planet A. If planet A has mass m, what is the masd9uj 1r: il;bss of planet B?

  Two planets have the same ;2pq iyf ,drtgcts969 surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, whi ps qc6f99gt; 2,yrdtat is the radius of planet B?

  Consider a small satellite moving in a circu f8amehlh 67w w3y6pr,lar orbit (radius r) about a spherical planet (mass M).866h 7aew3pywlhr ,fm Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the .slmoc20iqt)w it8 )b same orbit. Compare the two satellite's w .ili0t 2bo tc)q8m)sspeeds.

  A person is standing on a scale in an elevator wq2lpi1q/):z,yu u yd accelerating downward. Compare the reading , ulzdwyu/):1p 2qqyi on the scale to the person's true weight.

  Who was the first perxt0w5yqe ituww1,4;d ( 6xdfgson to realize that the planets move in elliptical paths around theexd5i,1xy( wd0qtfwt;u g4w 6 Sun?

  The speed of Halley's Comet, while traveling in its e hcm1e d5,-+zwulg8yolliptical orbit around the Su zcg+l 5m,udh-8owe1yn,

  Let the average orbital radiusje dc gt2p)ynr/o,t/2j5u6uc of a planet be R. Let the orbital period be T. What quantigt)6 2jdtn curco/ y5/p 2euj,ty is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda,(a2rgt eehp v/ -kcm+7lf2 *kg with the sa frv(c*glp et/2g-2m e+7kahkme 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 fro*9a1nt9yk23tn. ze y8ywnxev m the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-thiyyt1eazn y8k3t*n29v e9 .wnxrd of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.kel: c k7p0og+

  List the four fundamental forces in na7llzrz xk s,.a6;hi ,pture.

  An object moves with a constant speed of 30 m-c4 d2d9 zkkgz/s on a circular track of radius 150 m. What is the acceleration of the gk-d2k 4 zz9cdobject?

  The maximum speed arouneg v.8a* fk9 hn+r*7bngbgvt:d a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume allfgg g89+:a 7.**tbvnvhe rknb other factors remain unchanged.)

  What is the centripetal accew)iklq oo na:i*j 28t6leration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike isoq*nl )k8o:jt 62a iiw moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m wwh0tt ( 8ma/vfrom the axis. What0wvah/(mwtt 8 is the centripetal acceleration?

  How many revolutions per minute must a cmdm/hn5 0.gml c, k0w- k p.skm0qy*zcircular, rotating space station of radius 1000 m rotate to produce an arkwn*/s0dhc k.5m0 mq,p zykmg .c0-l mtificial gravity 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.vf 2y +cddvjn it;e8c33q -srx ;nf 2:po.ubt75 km/h. What is the tcs+;n:xcf7 bvp8-y f3;nuetr2od2dj. qi3 v centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Th(t,:20)nzbprc5br grbvg wn(fb6nl 0 e system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. Whatbfrbb5(ng,lz0 t) wb2( nrg60 vp:ncr is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attachexb7y vm(zh2b 3d 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 is 3 times the stone's weight. The stone's speed at this point ism32hz 7 bvxy(b given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical cirjrbp. x9j:u.d : xgnn055(ajk id2ddbcle of radius r. At the exact bottom ixnx dr0jad: gpdudk5:5(9bn..j2bj 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 experiedqaxg;wz;u95 ( y ;ibmn( 3dwfnces an acceleration of 4g when pulling out of the dive. What is the radius of curvature of thenqw;wz(i5uy; x d93; bf gm(ad loop in which the plane is flying?

  A pilot makes an outside vertical loop (in wp8 p t5jpd +2zc8)w 8xnpm2ptdhich the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-halt+2dxm p)p 5ndc8t 8j2w pzpp8f of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight.: efxuh(zgx56gv0d s/ What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolera/h6: uvxfgdgz0 5s(e xte at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radiupbvjfd.7f e.)d nx2e4zy,w3vong);ds horizontal curve with the tires on the7v d,bny)2v)n .3xpowf zj. dgfe d4;e 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 surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. Thege6dllh osqp08--j :yylm(5 f cent--:hq p8(l5oyfme6gl 0ld yjsripetal force 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/sax-fvfs ; 8)rp. What must be the m x-8)fvpf r;sainimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constaoaq2zn+ ee8 /int speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum raq8z oien+/ a2edius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympis /rek.jm-fn)c bobsled to negotiate a 100-m radius tm/ re-s.n kjf)urn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ruzv gr16x(m 3:fkl2px.4nnxngj3; /b:opr ema n 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 of radius 100 m, banked at an angle ofedxg nldc *hz4tx1-nbm 3j 9 u:b*k:s3 $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is jt 9110v2 fmlz oy/7qulw6 ojj9rbr,bbanked 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 strin;w:1rzjsr -dk5yn3 * eh ort9pg is revolving uniformly in a horizontal circle of ra 1*erzsht-po53dj; 9 krny rw:dius 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, a rzm/vsyp6d. tf6k2s 7bqj 38fpace car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in nus6f8kv6y. 2qbzdfsjp/3mpt7merical 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)9fhe mx c:h-wsts 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 7m h zju.3bmqss+0l8 4u0-kg person standing on the Earth, due to the Moon? The masjm +b zq30m8 us.4hluss 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 maszm -.inm36d buses is F. If the masses are moved to half of their initial distanczb n -6umd.i3me, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the v8gfb+* ng) tu; g 9y9jiopmn/Sun, at what distance from the Ea nnm*t)gj9gu pigb+8 /o; vyf9rth 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 imcnohlrw wq.ceh i /z cy*z,-,51gp.- s $7.4 \times 10^{22} \; kg$ 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 aa sh,gmde-k jhijd:e9 ,lm28 )bnu 3d. distance above the Earth equal to the radius e8k-e9dd u :3b an jlidhm,.m,2hsjg)of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfa/.(5pp6 j ugwpnmrg;u ce will tu (;pu.j5/wgpp6nr g mhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to f() glxhdhyrmj7hd:i69 mi qa8h8;h: 3 times the radius of Mars. The acceleration oh7;m lhai6 igr()hh8: :hjdd 8qyfx m9f gravity 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 gh/yyt;wu)jxa/kv - 8 acceleration of gravitya;)ht y/g jv xk-w/y8u 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. The Earth has radius r.evqgu )i5;cs / If ts c)gqu5 ;iv/ehe object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he0om*.p.oze9j/ gwj u:c4dsjhp qk*/ p goes from sea lzj*pg/* kcj.p u 9qm.poos j4: 0whed/evel to 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.n6q+a veatp; above the Earth's surface.6vq;+.ea napt What is the satellite's weight?

  A spherically symmetric6, 8xvc4c9d cmrkukc6 planet has four times the Earth's mass and twice its radius. If6r8 kv46uc9kcxdc,c m 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,ddd+g5j*j :jle9(8uw3 ba whi and Sun all lie on the same line, with the Earth between the Moon a l39w:dew 5*bhdj8gujji(a d+nd 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 trana43iz f4gypi0 gk) -rhsported 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 about the Earth (i.og)png: w,s8u e., it just skims the surface of the Earth). What is the :s)uo g, n8wpgspeed 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 skido)v0n* 8 ttn( p yvr9mk6.fqlms the surface of the Earth). How long does it t( vq08fnt p)y. o6*lkdm 9vnrtake to 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 the surface of the Earth. It is 5kgfh d2a ub (,x2:mr+zuv,ff observed to havmrx ahd ,gu:b,ffv2fzu2 5+k (e a 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, has an orbital dia 6xf j*bct1-wometer 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 planet with a radiu+,bgmzq pzwx- go+-; es 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 3jq*1j irj zrifr.q9ubx 2 )0a3azk(enearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orb.uq32 9 xr *jab)31izqjiaf (jrzek0rit?

  The planet Jupiter isihc u9/yd -5vorv0ed . $7.78 \times 10^{11} \; m$ 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 yearsma9f/b 5,i xaa to orbit the Sun once. What is the average distance from Jupifma9x5, a/aib ter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)