Is it possible for an object moving with a constant speed to accel8dho*lyj+,9 zinlx8q erate? Explainx9+hnj zql,iold*y88 .

  Consider a particle moving with constan0:nb 4dbnh7zq+snd28yx tubl-7 xnu 1t speed such that its acceleration of constant magnitude is always perb2hnsbz l0+utbq1yd8u4nx x7n7 d:n-pendicular to its velocity.

  An object moves in a circular xje/kxkguodlo uar 4c: (c(p-)tt 9. 7path at a constant speed. Compare the direction of thxux7jgkd u/ 9 or(c(etk -.pa4 :oc)tle object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the directi:9u-l whr ai.aon of the acceleration i a:h-wraul9. is

  Consider a particle moving with constant speed such t;*ulqp l e5t1bhat its acceleration of constant magnitude is always perpendicular to its velocity *q5 1pl;tuelb.

  What type of acceleration does an object moving with constant speed in a circpwputr 7:ebg ir107; zular p r7r :t1zbgwpu7ip e;0ath experience?

  What force is needed to make an object th(m j.+w-msh move in a circle?

  When an object experiences uniform circular motion, the direction of tig tw,1 vuvr-9z0rps4he net fors9pz4 ,wg - ivr0urv1tce is

  A roller coaster car is on a track t kkecpooyny) ira2 38kr14g 02hat forms a circular loop in the vertical plane. If the car is 3 2i4 )1k aooenp0yry2 rgk8kcto just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a cimr)6 +9s) jdq2jm7ijir8ad83xhm ip frcular loop (radius = r) in the vertical plane. If the 7ij+m prx6siajrdmqhid)f9m 8 )32j8car 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 follo syer;4d;oc4o ,vm4r jws a semi-circular arc until it is going s, 4vo;jr y;44mdscoe rtraight 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 of rakg usc;m) 6.hh/mvy/mdius $r$ 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 goes axff-yiz8sd( n*1 tf-eround the same curve at half of the originazyf-n*-fx(8ft d si 1el 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.y:hv(71khxe -hb 134qvlslh 1loeo n5 Then it goes around a curve of radius 2r at speed 2v. What is thn1h-l 7k1b s3 y1:q el5h4lexvvhh(o oe centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes am hpfelm7h /36round a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the cm hhlf3 /6pme7urve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsleb/uafn9qxu - 3(l qx/fc/jzi0d 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 smalle in(0 xuqu q9jcfa/fx3/-zbl/ r radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn onh;g.cwpzq h5,ihp:) z the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall5 . cghh)p,qi ;zp:zhw," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path t7 sfn4 rbi4)-j*pq ivqo have both centripetal and taq- i7v bq4i4jpnr fs*)ngential acceleration?

  The gravitational force between two oz*89f*4le5sc bw b dywbjects is proportional to

  The gravitational force uqx/y-q);) m3degjdy-e gs7x / ;nzhmbetween two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between theirw3yl7s1nvqqzn 6)l k( centers is cut in half, the ksnlq7v1 6 z(w3ql)ny gravitational force

  Two objects, with massese/tl yzwkrzrb3 e7 ;i*ic x-(. $m_{1}$ 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 masse+yoygrz-9wy/:b r mq9 s $m_{1}$ 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 unive3 irz 6u,ixardl))4 byrsal gravitation.

  Compared to its mass on the Earth, - oeue4 z)d1vwthe mass of an object on the Moon is

  The acceleration of graga )5gbl)cp*,odjm*u - .mb aovity on the Moon is one-sixth what it is on Earth. An object of m5b*ag.,o cl *oj)d-p)bgumma ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's su4bo pm x1-+ppl)g fb3c s1lvqyig1qo4 ,9ggh5rface, the rocket's weight

  A spaceship is traveling to the Moon. At what/0 9m/qn qob1xphe(ek point is it beyond the pull of Earth's gravqxo eh9(q 1 m/enb0p/kity?

  Suppose a satellite were orbiting the Earth just above the surface. What is enw7 82myx taxx)u0,pmo3rt 7its centrtm)au2er87,x wn txx3 opmy07ipetal acceleration?

  A hypothetical planet has a mas i;)/ 8dc8v5 kgvnbxxn/zmr8ms 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 acceleration due to gravity at the Eartdkx)b c;/n8 x88m5/gzvnmi vrh?

  The acceleration of gravity on the M1c.gwdw*( :z m knk.gdoon is one-sixth what it is on Earth. The radius of the Mo zcnmkd. k.wgg:w*(d1 on is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same a,kl1a1 ny3brus, 0f/ut y9wisurface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the masrsylua/0a 9tyw3ufn1,,1k bi s of planet B?

  Two planets have the same surface gravity, but plag(jc 3d w5dyivxo 7o6g)/1p eynet B has twice the mass of planet A. If planet A hasgiyodeg5xv1 /w7 p y( )od3jc6 radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radiuuqn/en tfwt.g+mi-n5 5b. :dsvk 2ji+s r) about a spherical planet (mass M). Which exprenvjt:/ g e5dks5-mb.w+ 2. +iftinn uqssion gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotate-q :qt dq0e1)hp0 ow: ocsvei:s in the same orbit. Compare the two satellite's speeds.t-)pcqe:qo s:0dh: w1iov0qe

  A person is standing on a scale in an el6gn kz *(dfzj b*+l/mzevator accelerating downward. Compare the reading on the scale to the person's true weightfb*zd6 nj+/ m(kgz* lz.

  Who was the first person to realize that 4hfi ezf1u:j0 the planets move in elliptical paths around the eh04fi1z :u jfSun?

  The speed of Halley's Comet, while traveling in its elliptical or2* gty:m9z9ryqvnq;a bit around the Suqy*;qt:99vnr 2ag myz n,

  Let the average orbital radius of a planet be R. Let the om 5ip;5scz 6crr,n fsi+bh+* jrbital period be T. What quantity is constant for all planets orbit+c5rzp rnbif,hs s;65j*c m+i ing the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the xoxa-op:9cdxpp19i - same orbital dia1xdp xocpo i-p-:99xa meter 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 Ea* 4b3;mk 7 )mnaeuumx7l/fo jirth to the Sun is defined as one "astronomical unit" (AU). An astero bnfuu*x3makjeo)l4 i/m m 7;7id orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.n+b.bv99 f twq

  List the four fundamental forces in nato8( bw13cfpkpg o70lmure.

  An object moves with a constant speed of 7 *k-ot *jy p4oje5zez30 m/s on a circular track of radius 150 m. What iey5te zoz-j7* p*4jo ks the acceleration of the object?

  The maximum speed arou. 8+ mnmxfhbk pl186dlnd a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remafmh8 6mk.b pnx8d l+l1in unchanged.)

  What is the centripetal accelera( 6mrd3 :tkw2 c2vprm o8g(gymtion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 v(8g (tc6k:d2 w pmy3rrgm m2om/s?

  A point on a wheel rotating at 5.00 ro( xr-xw9,vnr ju/am 5(fo+ahwqt -7 tev/s is located 0.200 m from the axis. What is the cjx-u v w/wrtrm+5 a-qax (t h9(7n,fooentripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of radiugzzuew *3u:t( s 1000 m rotate to produce an artificial gr:(uwt z3ge zu*avity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It 8ca8sm8 jbzk9zw+ gn) goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal98g8nz+wmjbz8sa ck ) force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m stringxu iziz):w7tv*;r7cs. The system is whirled in a horizontal circular path. If the maximum tension that the string ;zu )itw7* zc7:vsxir 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 attached tdte4h4/c4 n fso 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 w4sn4eh4/fctd eight. The stone's speed at this point is given by

  A stone, of mass m, is attached tkkggv oj90j )t8jpx.8o a strong string and whirled in a vertical circle of radius r. At the exact bottom of the ovk)pjx 98jg. 8t0jgkpath 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 experience3stj.;kl(hm-zucqfx l p0x.8s an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the f.pt;08kl(ulxx mh jq .-3scz plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is benea7zu1 v5cgm(gd o.d/ctth him) of radius 3200 m. At the top of his loop he is pushing down on his se (dvz uog5d /71m.cgtcat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand iovr-f hc ba,12zk97uzs 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 tola,uf1-7h zcrbkz29voerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires h dla :n.746kjl-skzbon 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 e6l sd nk4.bz jla-:7khach road surface.)

  A car is negotiating a flat curve of radius 50 m with a ia;if c :+e(dzspeed of 20 m/s. The centripetal force provided by diza:fei (c +;friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of yl+hhm7m2( sb radius 50 m at a speed of 14 m/s. What must be the minimum+2b hhys 7m(lm coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v k17 fcz0v*cbkaround a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stakb7fc1c0*k z vy on the road?

  What minimum banking angle is required for an Om pzxmp8,2gsh4 tma1/lh6n b 2lympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictionpp6,bn ma1 8 ltz /hms42xmgh2.)

  A horizontal curve on a bobsled run is bag 1ir: fhjm qyvs2 qzuo7p)+l(+04r sunked 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 ofm *grnzw//k..pjy j,g $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banke xu,g10e3mg* mj 9 g3kzjya-xld 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 unifor2/vtiwhh+wv 7 mly in a horizontal circle of rvwwt +hihv/ 27adius 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 race car accelera (f0q r+ d08yfn1bwapwtes at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (ow fw pqyf01a8(d 0bnr+nly 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 consistfjlxy h7+sva /eis:w4i 5b i/b++ zt1is 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 persw:yd.vrde4 je3xn*+mr p ;us(on standing on the Earth, due to the Moon? T*n4u( y 3w+d;jererx:d.svm phe 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+ 9bx 6egdsk-v force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attra s9g-+xbdve6kctive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from th7 u mq qrf(3j25cxgc;fs)*kige Earth will the gravitational forces due to the Sun and the Earth cangxcf q*(mg3fcq5)7j2uk;irs cel?
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 isqju 75n1wa+vvh ae 1k j0,qgf; $7.4 \times 10^{22} \; kg$ 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 the Earth equal todl gxeg-w* x10 the radius of the Earth. What is her accegxg-xl1 e 0dw*leration due to gravity?

  The radius of the Earth is R. At what distance above the E+ c q hogahszd4mm2o1q:* pb3+ fd5mx*isn7d4 arth's surface will the acceleration of g 3n*d4cfxsqzdbi5+ mp+:oqhda h4*2s7 mmo g1ravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above itsnf1z s36zi) qf surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the sfzi)6qz31f s nurface of Mars, is

  At a distance of 14000 km from some ps/squ3 1b u, hq(x1nsylanet's center, the acceleration of gravityq,b1sy qshs1/n ( ux3u 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 Earu5g;0ool:gm/oiv)jbw vo9 c 6 th has radius r. If the object is raised to a height of 3r ab um cvl9i6;b:ovg50wjoo g/) oove the Earth's surface, what is its weight?

  By how many newtons does the weight g)2gdy w lbb-:of a 100-kg person change when he goes from sea level to an altitude of 5000 :dlwyg bb-)2g m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellitksl.j u-pn0uz /8t m8he of mass 100 kg is at a point 3r above the Earth's surface. What is the s /t-.nzju0hl8km 8 spuatellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twiceiqf. 4j+bcskud 6 op79 its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, hpo+ is6f.bujqc7kd 49 ow much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sunz8fufzt9q z(/.miz 0/uc*gmdh8 gh /z all lie on the same line, with the Earth be9q 8*zzhf/m/zfi .d /z0hggz(8ctu mutween the 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 uls,bsg2jo.6to 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;)j yebr3*u2x,m yvob 50aqdd circular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius o b*)oma 2,jbur0xy5y; eddq3vf the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it justmpofno.1 l2fe/0r- k dvntan-5dy 1. n skims the surface of the Earth). How long does it take to make one dtn a.y/0r5.o-nffk2d 11nmnlp o ve -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 8p0+iihvculj4m-t r0 of the Earth. It is observed to have a period of 89 min. What is the mass of the li0+vh4 8rmu0t-ji cp Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupit8lr8 *u xy1jwgp3w w+:)sc gcoer, 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 Jupiter orbits the planet with a rab1llp.h *+9;fzbdy wu dius 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 orbi98wb 7a3 4n., wigxueirn (6xkc;olr xk*tjq7ts. Moon A has orbital radius r, and moon,7 qetk8c .anxn xxrg349lj6*;wwii k7(rubo 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 i:n ,h6ufx:rckc;6vd0l-w dz ako.j o3 j8 (ivqs $7.78 \times 10^{11} \; m$ 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 fq35e )jf(vc)*ogezm:e7uyf Sun once. What is the average distance from Jupiter to the Sun? (The dis3m5feg)qv eju)z7e yff:*c( otance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)