Is it possible for an object moving wi fgtb3c9/*zy*3 ny pfhth a constant speed to accelerate? Explain 3nh3p czfy b*f9/*tgy.

  Consider a particle moving with constant speed such that its acls3e0dh6. yg rceleration of constant magnitude is are 3s0gh 6ld.ylways perpendicular to its velocity.

  An object moves in a circular path at a constant speed.4hxj) ihq- f ihu 6mqqat e+.)zw8/na) Compare the direction of the object's v)84/ a)aq nh.fe qumxi6q)jzi-hw+t h elocity and acceleration vectors.

  When an object experiences uniform circular motion, q f8,go7 uof,d the direction of the accele8ud, f,o7gf oqration is

  Consider a particle moving wi fs.3v7omdpe c(mp0n/th constant speed such that its acceleration of constant magnitude is always perpendp 3epmvdn. 0s/om (c7ficular to its velocity.

  What type of acceleration does an object moving wwc8k3fmf rs1pm 27avkfjf+gz e:. n) 3ith constant speed in a circular path ejfs7:3k2 wa3km)fz 8m+p. erf1nvcgfxperience?

  What force is needed to make an objec)ar u,6x4alne jwha8-qoc3qs0zf)90i vrh;t t move in a circle?

  When an object experiences uniform circular motion, the direction of thec/en/ gxb iz0addx;.0c k so:/ net fori/ :c/.bzc0exsk0a do;d/n gx ce is

  A roller coaster car is on a track that forms a circular loop in thh+b s8,j1 ojjge 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 acceleratg,js +bj8 joh1ion at this point?

  A roller coaster car (mass = M) is on a track that forms 7kh6s;qy9pp n a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact7n ;p6hspkq 9y 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 0v*xv:9df)nuxnge4 /h:;pcog m:aap dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowonn capaxv0p m9):exg;f*vg:d:4u h/est 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 br:l )b;dg -lut8n6ib$r$ 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 constanth vli4p ).nlfy79g/npj-aaq ,-as+be 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 goesa+)79 -alf-spjba.i/ylehn g4,n p qv around the curve for the second time, compared to the first time?

  A car goes around a curve of rad4 i in8cwwg96h 7 qw*-xomh(idius r at a constant speed v. Then it goes around a curve of radius 2rn6iih9io(wqc-hw7 4m xdw* 8 g 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 around a banked curve of radius r with speed v. If ehq*4zac7z57 nnp7aj the road is fr7nph57 7*az4nc jeqazictionless 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 bobsleln+qb uzlw (-ktu/28sd 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 smaller radius curve is v. What is the salu/(kut+z n2bwq8- slfe speed on the larger radius curve?

  The banking angle in a turn on the Olymp-r feskqzkqsi 0/, d*kyc d7sr: qa*)*ic bobsled track is not constant, but increases upward from the horizontal. Coming around a z-kdc*dqa,r /7rs ) *isqy:q*skk 0e fturn, 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 a*(wleiwwm: 9drgd6y 7n object moving around a circular path to have both centripetal and tangential acceleration9dwy7edw: 6m(r*wilg ?

  The gravitational force between two objects is proportional to( kg(m-h*n vi +twfj-u

  The gravitational force between tw4rw07ninz mt7n9mpwg ,u1 pe6 o objects is inversely proportional to

  Two objects attract each other gravitationally. Ifts0 ag xu86kt: .6sigwn4s (8d ajud2q the distance between their centers is csa s0a 4dn6 q2uwkj86tiggsx8 u(d:t.ut in half, the gravitational force

  Two objects, with massyrywb,o dd/43q xbl,qf7cirj( 31b5 n es $m_{1}$ 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 masse3 5/ olct;g g.yla.xx* vesj1us $m_{1}$ 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 gravita6joeb*:l3ty v;l: xv htion.

  Compared to its mass on the Earth, the mass of aa 7hhgnbbe.u-8 6d- bin object on the Moon is

  The acceleration of gravity on the M*wxx+8wtovuy n yv ;quwk9)47oon is one-sixth what it is on Earth. An object of mawqynxw 8v;4)+v wko7u y9*u txss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, t weuu1/pc3 kf;he rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull x9 gy 317dj kjd)ml+uzn+v go7eqj6b8 of Earth's gravij3m nldd +v)8z x961ggy qjju7ko+eb7ty?

  Suppose a satellite were orbiting the Earth just above the surface. What(ud o tuef-*y-l ppt o;1qon.1 is its centripetal1un *otod 1l-pet(yp.-;q fuo acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twic-8afkcnf0kk)ze u: o 5e that of the Earto0a)c8e-5zk :nukf fkh. What is 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 onlqw9/6s cd0fv; 06o onw( ucs;0bnxuge-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?w(0u6s ;; w c0 nu9f6xsl qbgvod0/onc

  Two planets have the same surface gravity, but planet B has twice the radius5-m,j2 k/ nry:agtg v7njo*el of planet A. If planet A ,akj-e 5on7yt2:ngm/rg *vljhas mass m, what is the mass of planet B?

  Two planets have the sd/ndt oobu6* ;ame surface gravity, but planet B has twice the mass of planet A. tduo; / 6dn*boIf planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit ty /56v e y*lxhc,k:ffiqm62c (radius r) about a spherical planet (mass M). Whichf:k yxe 5lf/m,*qi 6hc c6yt2v expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellist f9g,)rfoc8te B, and rotates in the same orbit. Compare tho,8sr 9)ffgcte two satellite's speeds.

  A person is standing on a scale in an elevator acceleratit)ciiei u y;43ng downward. Compare tuti 3c4i)y;iehe reading on the scale to the person's true weight.

  Who was the first person to realize that the planets movez/dn* q(o2kkm in elliptical paths around the 2/(kn okmd q*zSun?

  The speed of Halley's Comet, w4u1abwaw,b 93q:j d6vhi qt8chile traveling in its elliptical orbit around the Sun,qab t9a,hi8d3 bww jcu4v :61q

  Let the average orbital radius of a planet be R. Let the o3ovf u524a k5liy 8arkrbital period be T. What quantity ia y4 8loufak 5k35iv2rs constant for all planets orbiting the Sun?

  A planet is discovered n0r ydd )98:,nhsafud6)(d-yz yxrzsto orbit around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the peya z9)hdd) z8:6dydnfrnxrs u0s- y, (riod 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 one "astrono- mp/wfapai jrp.xyo+07-w l -mical unit" (AU). An asteroid orbits the Sun in one-thjpya - mi7a/p0-+- lwxo wrp.fird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.w6 ,(xg/qq:y4o lu tu:mc4c vk

  List the four fundamaazx-d - 0;s 6xurzvu:n wi:)d(f:oqxental forces in nature.

  An object moves with a constant speed of+ze 1.d evq*)t-b9h bd*sagky 30 m/s on a circular track of radius 150 m. What is the acceleration of t y1 zd. *heskabd*+-g)qteb9vhe object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum speed i-ml emy0bg 5ann((:w5lp* mf around a curve with twice the radius? bglniyfe5(n am :m5* ml(0-wp (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bic x+ 8nfrs9;hxpycle wheel of diameter 70 cm when the bike is mov+x;rfh npx9 s8ing 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is laynb ijbvrg7x)m(8,-3e ja:qocated 0.200 m from the axis. What is the centripetal acceleration?m),37anb axgi yrb(e8j: qvj -

  How many revolutions per minute mu x7nc37q oom1ast a circular, rotating space station of radius 1000 m rotate to produce an arto7 ocn3am1q7x ificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of re5u ):qf6 ossf 6,mprqix15l 250 kg. It goes around a 13.7 m radius turn at 96.5 km5q om)6ifl1e5, srqpxsu :6fr/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system isrgnhzie)fmw n6 g,9k 2vm1kehnla5:70up30z whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is n 1fn,9e0:2u37)pzm khg6khwvinl0ar5e m ngz ot to break?

  A stone, of mass m, is attached to a strong string and whirled in a ve) j3bm vd /x77z.k+hn q: 3fxnjl,xbszrtical circle of radius r. At the exact top of the path the tension in the string is 3 tim7zj b+ /sn3dx3, .hxbl:q zx7fk)j mnves 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 vertical muyig-89rmjbglv .8pr9 8*gg +9c qricircle of radius r. Argb8 qij*ggm -icup.8ym9+lv r g99r 8t 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 given by

  A jet plane flying 600 m/s experiences an accelera31sxuiism40z /0zjsz tion of 4g when pulling out of the dive. What is the radius of curvature of the loop in which thz0 sszsxzi3ui/m1j0 4 e plane is flying?

  A pilot makes an outside vertical loop (in which the c0f.yxmj9/v fhqw /w, henter of the loop is beneath him) of radius 3200 m. At the top of his loop,q90w j hf vfh.myx//w he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can sc8:j xxwxqmg-p 7e:)4 fntby2tand 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 tolewf- x) :4xc8eytmpgn q2bj7 x:rate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontaly39af;tk g(eba3;ll q y ,s*yu curve with the tires on the verge of slip39y;labua y gs , (*;3etykqflping. 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. Thy -( rdh3 pm)e,4ltylpx-ny qy (d,ov4e centripetal force provid) ,dntey(d xhl4yy-(v,yqol 4p3m-pred 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 l1n82njbv ,x9fh ra9- ijtb,x must be the minimum coefficient of friction between the tires and the road for the car to make the 2h n1b-f bvx,t,nijr8alx9 9jturn?

  A car is moving with a constant speed v around a level curve. Thbheq;vhn;t l22 zbn/ -s0ui+he coefficient of f;hz-+bib;0 nvu n/et2h2h l qsriction 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 Olxuzl)d ,cvp0r1na3b1 ympic bobsled to negotiate a 100-m radius turn at 35 m/s withou d0r 1uza13xvnc)pl,bt skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at;,0ydp2 7rwsd v-koe ,6dlv uf 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 ang vwr:baw7twf xg6478w le of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked avv82 4gbjs0wr*u /duh t $45^{\circ}$. 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 revoage0v t*nybke .v+uf5p a h.f8c +s1:xlving uniformly in a horizontal circle of rad e p:tbef8ag * s.. 15n0vfh+u+yvkxacius 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,pljx7yi j0 7j-4o q2bu a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on p2jy- qx jj lo7b704iua circular 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 of a proton of mass bvqp.* :zi *j-d y s1duq*p-dw$1.67 \times 10^{-27} \; kg$ 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 thns :fbzxv) / 2xe3/upzylvq7.ms)xs;e Earth, due to the Moonlsf/ u;/x)2 bqpxyez . nvv3)s:m xz7s? 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 attracti u(s-t /:r68powrwu .sph3uyave force between two masses is F. If the masses are moved to half of their 8y.puusr(p: a-3whtrso/w6 u initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from3:xredl( xpj + the Earth will the gravitational forces due to the Sun an x+ (erpl3:djxd 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 6zu (,s3qrjf jkyo er)p9sy06is $7.4 \times 10^{22} \; kg$ 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 Ear3z( (pi n-fs911mp(9gg4hstcy a ypzil v36trth equal to the radius of the Earth. What is her acceleration due to grs 1fctipayz9it (l-34(g h1g nsyz9pmv( 3pr6avity?

  The radius of the Earth is R. At what distance above the Earth's sur+ 9f)9txrhbc h,)u f 2x8oecyhface will th9cec2) byh), fx9h8ofru+xht e acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mart mnpt -re-9-uhxwab.e5ksh8q j2n /8s at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite n-b ws rp .t-a2t 8-qexj/5nhhke89mu, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, tzo8upx dr7vbc /i w:u 70yd13(og+ ejshe acceleration of gravity wcoudz3uyid1+77xjv:(/ 8 g0p broseis $32 \; m/s^2$. 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. Togiwqamx/)od+ mj6 o)1t9o(y.ru ei7he Earth has radius r. If the object is raised to a height of 3r ) j uiy(rgia)x+/o7w mq. 6mod19oeo tabove the Earth's surface, what is its weight?

  By how many newtons does the weight of a zlnfv 2 xm(n-pbkm:8c1hr * 9j100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth k m*fhp-29bnrl18jxnm (z v:cis $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is .novn; ggnhv y6f7c09 at a point 3r above the Earth's surface. h;0yg n 9vfn c7n.gov6What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its rc- g2zzk106murid9 w sadius. m6z wkdcs i2 rz9ug1-0 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)2gn dunte34w lie on the same line, with the Earth between the Moo ) u4gwendn3t2n 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 transportedcv6f;1-. ;qh;usggs h2s vc cd 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 abou c5;x*3 g*n,fvb zyd7l dffc/h;c;cjqt the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth is fgz,/7 yffc xchnd bvcj;;5q3cl d* ;*$6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orza3ba0b sbj2 04 ;4yvyuko bg1bit about the Earth (i.e., it just skims the surface of the Earth). Ho;u132s abyb0z0g4 b ajvk4oybw long does it take 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 abovaqnj2+- (a0grcge g5w e the surface of the Earth. It is observed to have a period of 89 min. What is the mass og jwq ga50g+ ran2ce-(f the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has avvt/d98he;w2b 0 rg5vs jy0 yfn 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 Jupit mh2(gsoi / l6xyu91tzer 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 hh) j inj39cv;d0 2vsucas 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 orbit?v)cc9 s 3vijnh;20dju

  The planet Jupiter ien5rxelz otz;p9k61o 9bb,j: s $7.78 \times 10^{11} \; m$ 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 once. What is the in24ztjn;r )paverage distance from Jupiter to the Sun? (The distance from the Earth to thr ;4izp )2nnjte Sun is $1.5 \times 10^{11} \; m$.)