Is it possible for an object moving with a constant z3 o s0 p/rlmq7bg24uwspeed to accelerate? Explain.gobm4u730 2q wrzs/ pl

  Consider a particle moving with consta7)e 0 ar3v -((pth k0vkccritlnt speed such that its acceleration of constant magnitude is always perpendicul 0e (v( 0vta)73kti lrpkchc-rar to its velocity.

  An object moves in a 1+q( csx;wev c 0aw1pocircular path at a constant speed. Compare the direction of the object's velocw1c+eqv;( pw ac0x s1oity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of t62k9v.,f qcuih l y65/mxse qjhe acceleration/k6vj2yc5 q9 ml,xu. fsqe h6i is

  Consider a particle moving with constant speed such that its acceleration oex( 87j9zehh7es aw82vvr e;gf constant magnitude is always perpendicular to its velocityv(h we7 h798zj8 ;axee2segvr.

  What type of acceleration does an object moving with constant speed in a c1oc1g-ee9 zyq ircular pygzq1 e-c91e oath experience?

  What force is needed 88yj+z ; apn(bwz1 u* (lmxroyto make an object move in a circle?

  When an object experiences uniform circular motion, the g(on/4flulx efdm00hv*v ( 2 ddirection of the net force ifd(0e* omxh4gf l(nuv/d0vl2s

  A roller coaster car is on a track that forms a circular loop in the wgew8qzrt.vrn:v59kiu bkh* 70x7 h:vertical plane. Ifuenx5w vt0 .z *i9:r7k hqbrkg7:h8vw 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 this point?

  A roller coaster car (mass = M) is on a track that forms a circulxs9(w/tv1hjnqx ch k wi ;k:+0ar 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 minimum value f9(tsj:cq0 vw1h/k x h+wik;nxor its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arcq(/o kln t;lcs1 pc3-w until it is going straight up. Just as the plane is at its lowest point, the force onlqw( s-k 3 nlcpc/1ot; 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 rau8 cwklhk8v 8u;06dbjdius $r$ 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 td,8tycbguqrbl46-q h8 iu +:rt 6a2n it goes around the same curve at half of the original speed. Wh46br8c 6ylqtbu2:q +tn8utr, gda hi- at 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. Then itwx2 t-9au-e3.tli bev goes around a curve of radius 2r at spw ltb -e2-itx9a uev3.eed 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 e*u vbnyoi13kq z8sv (z6/g(h 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 magnitude qyzs(i (*nz vu oevh3bg8k /61to

  Two horizontal curves on a bobsled run are banked a2 - iaqygsbw)at;v5r+ 1mf,nkt 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. -ta5,m;s nfa)y2wv1bik+ g qr What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not conscmc.cm no5 +hbmq(5srocw p6*34 uqg,tant, but increases upward from the horizontal. Coming around a turn, smcocm,6 bcrqcn4qg(p mu53oh* w5 .+ 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 l8dmkto9c aw;49 v1) ua,0y)toepbce have both centripetal and tangential acceley1eudat ce4 k;bm8vo)cal0 )p 9ow,9 tration?

  The gravitational force between two obm 1to5 bi( vlv1g0exob*8du ;bjects is proportional to

  The gravitational force between two objects ubjxb3( .5s4d- t levjis inversely proportional to

  Two objects attract sw5qglld pw0i 4e:i3) each other gravitationally. If the distance between their centers is cut in half, the gravi)qdi5pswgi3l0l 4e:w tational force

  Two objects, with masses l+ ( 2i2arg9e gaq+idm2n kk;+nsn(cj $m_{1}$ 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 masses jwoe i fr/rd. en)1+xm*d; hzbwq75v /$m_{1}$ 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 unyik 81b:es f0hiversal gravitation.

  Compared to its mass on the Earth, the mass ofi2d9oj () itngcq2 6 28y3wp4zniwda wta8f7p an object on the Moon is

  The acceleration of gravity on the Moon is onez xkia gmm( vil dw0r6.5bs,y8.*hrc4-sixth what it is on Earth. An object of mac x (rym5.6 bwsz, 0.l8rmkahi4vgi*dss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's suryv wh. 2vj4:zhface, the rocket's weight

  A spaceship is traveling to the Moon. At whatb03g.i ql 1oao point is it beyond the pull of Earth's l0gqi o.31boagravity?

  Suppose a satellite were orbiting the Earth just above the surface. Whattwjo f:x0b z*2)zbi /c is its ce oj0) btbf 2izcz*w/:xntripetal acceleration?

  A hypothetical planet has es)9 ne vt)i2p geds7/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, tt)ed72n)g v e9s /espihe acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on *41p iyvw7678rkgctzrx uw( w Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compare7y* wiv187 zgu c wk4(p6rrtwxd to the Earth's?

  Two planets have the same sutl0; niyg:pc, rface gravity, but planet B has twice the radius of pp:;i0tg, yln clanet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surfacehfeltlrl.0a)ni +t -. gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is nllrfetat)i..-h +l0 the radius of planet B?

  Consider a small satellite moving in a circulmmjzys j8x045 4n. xmnar orbit (radius r) about a spherical planet (mass M). 4s jxx4y.n5m j0zmn 8m Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the sam8 tscx:ab5gho//mm c 3e orbit. Compare the two satel/h tmo8mc5 xsacg/:b3lite's speeds.

  A person is standing on a scale in an elevatov3ctt(i/g2., d tnivg r accelerating downward. Compare the reading ongcgi,t.tn/t2 v dvi3( the scale to the person's true weight.

  Who was the first person tok o:p8mpprq5l c22-lu realize that the planets move in elliptical paths around the 5rpl2-pqu :ompck2 l8Sun?

  The speed of Halley's Comet, while trav:e5qu2 aurc1 t wo7m8seling in its elliptical orbit around the Sun,mr 2q7:e1uauc5wot8s

  Let the average orbital radius of a planet be R. Let the orbital period be T.7yq o y.w.isq* What quantity is co *.w7qs.yqiy onstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with85 7xcuj ejhz- the same 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?58hju zx7 -jce

  The average distance from the Earth to the Sun is defined as one "astroeme8c )8.sufxnomical unit" (AU). An asteroid orbits the Sun exfs). m8 ceu8in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.r: /kyf ffl9s1

  List the four fundamentmp sl*u6oscet9vj pj6 u(; (k)al forces in nature.

  An object moves with a constant speed o.wopet 8om+x/t: z9v of 30 m/s on a circular track of radius 150 m. What is the accex o.ov8 +to9/ptzewm: leration of the object?

  The maximum speed around a level curve5 (vwbkkyll0npl x*:z 1ay 63k is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.)6 k1*wyp 5l0 v nz:yx3lkalbk(

  What is the centripetal acceleration of a point on the pmgik w8w0ds 8;fs7 l-46 pt vh3yz-lzoerimeter of a bicycle wheel of diameter 70 cm when the b6ykm w vsio- f7; w 38t-g8pll4shzdz0ike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locaacn 7i009mixq4i: y cated 0.200 m from the axis. What is the centripetal acce :y4anim09c q0ixi7 acleration?

  How many revolutions per minute must a circular, resr +i9)x: ,f.8 7dzze lh gc)ggj0knbotating space station of radius 1000 m rotate to produce an artificial grrglezz+)0h.kx g,c9i7s bjgf en:8)d avity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a)ybctk- *pfq1jc d t-4 13.7 m radius turn at 96.5 cpfjcd*q -1tk4yb) t- km/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 nl sadfx21-v0 is whirled fla0-2s1 dnvxin 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 not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical cpf *g0c;lzp p)ircle of radius r. At the exact top of the path the tension in the string fz*p0) ;cpglp is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attaqu18fjjj w*;foz dh4:e ,o(ehched to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tensioefoj qf:o ;h(hj, wju4 e8*1dzn 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 acceleration of 4g when pullingl/zx1m*3,m0jbss edr out of the dive. What is the radius of curvature of the loop in whicls0 jms1zex*d/m3r ,b h the plane is flying?

  A pilot makes an outside vertical loop (in which the center of thejq4xc z84gxh(p83 fdf loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normalpf48xq8cf (hd jg4xz3 weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. /xte 3agp6k,;fnhut ) What is the minimum radi;h63eu tkx )tn/ gpa,fus of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires ona 7y ku 1w:y gi2qiap9-w1krplh, .6wc the verge of slipping. How fast can , ailkpay-g97h2yikru. wwq c6w :1 1pthis 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 qm0x t d:*e-lydgo(0;gmt,zem with a speed of 20 m/s. The centrtg,d: *0q 0(ee-lmgzxm;yd otipetal 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/ijb8 xgme411m s. What must be the minimum coefficient of friction between th18mi bxem j14ge tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve.+xo:ssdl pu gw+ 4 -jcrd*oa37 The coefficient of friction between the tires and the road is 0.40. What is ss +ag* rddo:u l+jw3poc-x 47the 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 negotiat(y: 27kpnl yl tv)3cxae a 100-m radius turn at 35 m/s withony:k2y3xl ap( v7 c)tlut skidding? (Ignore friction.)

  A horizontal curve on a bobismt+0hjm,js/b p 8ykt+0y3gsled run 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 radius4rf6 4 yi gy)ubow clh:q6pknc 0hl+1: 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m iubd*a9g./u tks banked 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 uniformly in a horizontal cx zp 0:s1piir/1 zw6jlircle of r ppzs1r/zl6ji : xiw01adius 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 are.3gkooo b0;t oqx3 a/ed68jv:;l yluia, a race 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 numerical value in the blanks) ;oqy0j3t.e o 8auvg:bkl6 3 x ;olio/d
(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 massgw6t:2sh svw- $1.67 \times 10^{-27} \; kg$ 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 4po t q /n.te6w,hsmc5person standing on the Earth, due to the Moon? The pt65q4s,wh e/nmoc.t 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 between two masses is F. If the masses arj tcvehe6-m/hvr0 +dtp1jz ,5e moved to half of their i v+dt1zc6th,h vj/ermp5- e 0jnitial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward tmqo6c jm/h s88he Sun, at what distance from the Earth wils8 8cmh j6qom/l 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 is ;uv(0 s7eg qwuzuuq.5 $7.4 \times 10^{22} \; kg$ 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 abuzs:)rg3 8ev move the Earth equal to the radius oevm3g) 8zs: ruf the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. pyaa.arh+e9m sw40.ai6hitufc7*k. At what distance above the Earth's surface will the acceleration of gravity be iwp.c6 .amkruha0a 7f9y .ihe*tsa+4$4.9 \; m/s^2$?

  A satellite encircles Mars at a distance ab5, onipk ym- gmeze03,ove its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of grav5 yeoepg i -,zmk,mn03ity on the surface of Mars, is

  At a distance of 14000 km from some +ey n d1l)jkl 28,kw0t/fir xp+ai qk-planet's center, the acceleration of gravity i1/)xta-nj,f ylie2i k0p r +w +dq8kkls $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surfaclnz6;f/gj 7,pf+ q ouje of the Earth. The Earth has radius r. If tljnj/pf+q;o7 ,gu6 fz he 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 afz,f kq ynaq6 ;s,e1q- 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radq , ;ayq6,- 1fnqskzfeius 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 3kr,g bn7hh -w6::et xp)d6pssr above the Earth's hgwr : ps-d6n k6,)7 bx:phtessurface. What is the satellite's weight?

  A spherically symmetric pbeja.j7*hz +f*))v zsvv x 5lzlanet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surf 7.bh x*+j)ea*5lzsvvz) zf jvace 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 ligtos g+rq6td ,8x q clu:4)q;kne, with the Earth between the Moon and the Sun. The Moon has a mass of kttq8 +4c )6qgx;rsg d:, luqo$7.36 \times 10^{22} \; kg$; 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 trav 1xvs:2 a -avscg) dp:m(itx5ahs v92nsported 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.e., it just skims the aamz8hg y 5y;:/bu6olsurface of the Earth). Wam o5h ;6/a8yygbl :uzhat 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 the Earthiv8 zb e0 d9bk-uyh49a (i.e., it just skims the surface of the Earth). How long does it take to make one revol e9zbdh0kv4ayi-9u8 bution 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 wpjn)-cn7)g-xob / sr the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mc-bs)-wn/x njpo g 7)rean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbita8 w+so n*re2xm9v)7p1e obupll 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 +x+h q17y,c wwqq21p yogk 5zgorbits 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 f; ls)cg ,8p 42linvs.ltkq8lcircular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one ocikplln,lgl; ts24.f vq8s )8rbit. How long does it take moon B to complete an orbit?

  The planet Jupiter iqmb2pa(zg t, 5s $7.78 \times 10^{11} \; m$ 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 th,*l9i:yqykc+bald t0e Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun yl i*+bc9 y:adlq,tk0is $1.5 \times 10^{11} \; m$.)