Is it possible for an object moving with a constant speedsy.ty4jmdg9 8k 3q5fe zzr 55u to accelerate? Explai 9uz35k.ys dm 5qfergtyz854jn.

  Consider a particle mov;v7 xrec1 r5hning with constant speed such that its acceleration of consthrn v 1c5r;e7xant magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direcu8i;rz5 b7)zr a4t6upjn6ftw tion of the objen zw);rptutr68z4b ju6 a7if 5ct's velocity and acceleration vectors.

  When an object exper5.y:s wq6 y fs d8,mrrdhsdv*-iences uniform circular motion, the direction of the accele5s,sm8 6d*- dsvryrfy: hq.w dration is

  Consider a particle moving with constant speed such that its xs9 *p dt5fdh*acceleration of constant magnitude is always perpendi*h9ftsdx*5 dpcular to its velocity.

  What type of acceleration does an object moving with constant speed in a cirpq0f l+sd k1+levn(9qcular path experiefk+l pnd9sq e+v(l01qnce?

  What force is needed to make an object move in a/9li zvg 010iab d)bwtclekg ;,z97v)dge6d r circle?

  When an object experiences uniform circular motion, the direction of th 4s. bd,ai5z 5fbhwt2pe net forceh4fb5 btd2 iwzs 5ap., is

  A roller coaster car is on a track that forms a circular loop in ti4;k(e l r +szryiu2rt:f2w)khe vertical plane. If the car is to just maintain contact with track at the top of k2 fkz i)t+4;i 2uyr les:rr(wthe 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 circular loop (ldtaik 5) b+kc4 2utox -0nsy(radius = r) in the vertical plane. If the car is to just maintain contact with the track at thet osd 05liy ntx2c )b4ak(+k-u top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follco a6h(n8nvzo ,8 mb(xows a semi-circular arc until it is going straight up. Just as thzv(n8oabnx h m ,68(oce 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 rp1wqsvyqwah,))) 7 zqadius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curv6 f.gsyeetisnf s,36,e of radius 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 goes around the6esi ytnf6s ,e3.s,fg curve for the second time, compared to the first time?

  A car goes around a curve of radijjy 3ip63c*vj+chb0 mus r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second cuyp 6v+jj c*0ch3mjb i3rve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. If op *x8nsfvcqxu: 0- 0pthe road is frictionlx f qxc8:usv n00-pp*oess 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 aregte8jr: 2i. n 19xnqt4cwsfo8 banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the ruw nqg984o:ti12tc r 8xnjes f.n) 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, ;0ct bm4ctc0*u5pm0 r. vxhaebut increases upward from the hori r040ch;atem5p0 umt*b .ccvx zontal. Coming around 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 t rbvx4ywx/c(i+;m pl-o have both centripetal an icrm-+p/4b(wvlx y;x d tangential acceleration?

  The gravitational force between two objects is proportional ocbb +* 5la xnho0(si7to

  The gravitational force between two objects is inversely proportionalmolzb7;2wh+cvu5d 9f to

  Two objects attract each other gravitationally. If the distance betwekz:vdme*4: g vsn xqvf+u8+* xen their centers is cut in half, the gravitativ4u*f:v8e ns x+xkzv *m+ qd:gonal force

  Two objects, with massea 6/fd 5bl, j6o0nuwtws $m_{1}$ 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 4xij7s u44aup $m_{1}$ 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 ofs8.vrh wbob )q92c)tr universal gravitation.

  Compared to its mass on tb b 6-adc0u(omhe Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Eap: iebmib )m3jyqq0 y39 lv;8rrth. An objec qil i8vj9 me3m q3;rp0:yby)bt of mass
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 weigmw (o*(82r2htnjj nwaht

  A spaceship is traveling to the Moon. At what point is it 1b d ygno,i8a,1*hhhtbeyond the pull of Earth's ybai,hd,no1h8h1 g*t gravity?

  Suppose a satellite were orbi/0iw zy- map)tk 64poxting the Earth just above the surface. What is its )y p ipwz6m/0-tx4koa centripetal acceleration?

  A hypothetical planet has a mass of half that of th dx9ga6yu ji 4nzcz;y7px:9*de Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of zx*: yc9 d6zunp;y jx47a9igd g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth whfl7;ittm a88i at it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to t8ia87l;fitm the Earth's?

  Two planets have the same suf4 yw(we: xeyj fd*3* l*3elymrface gravity, but planet B has twice the radius of plan ex ej*(fy*yedyww3*m3l: lf4et A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of pj1bkz kea0e :y0q g8p6lanet A. 8yk:1aqb g kjpe6ze00 If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheri3m* d3 jw+db ;wm ;afjoxje;p/cal planet (mass M). Which expression gives this satellite's orbitjf 3d w;+am3m w*djejpb;;ox /al velocity?

  Satellite A has twice thd5b2fm2nyu )k hl9zvm4csn0q/ f z**ae mass of satellite B, and rotates in the same orbit. Comparem bffsz*n5*2 q0cv ka/ hyn9um2d)lz4 the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. 4r:fmneh n:u:h .+iuhe/ex 3k0o 9khjCompare the reading on the sch.9 nxn jri0uhfomeh43ke :he::u /+k ale to the person's true weight.

  Who was the first person to realize that the planets move in0cw2 )sdlrtsv x82u-y elliptical paths aroun2ws2l)-tcrx 8uyvd0 s d the Sun?

  The speed of Halley's Comet, while traveling xyr9-pa9jr p 9in its elliptical orbit around the Sjy-a 9r9 r9xppun,

  Let the average orbital radius of a planet be R. cj090c: y9xv en/xyomwf-73saukz (iLet the orbital period be T. What quantity isiwekzc na0y 9mx/s9oc:0y(xf u-37 vj constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with thx zu(mt1s,i 9qe same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what wi1qz( i m,9uxstll 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 defined as one "astrzd9* ilo ,8gluonomical unit" (AU). An asteroid orbiou8 gz lld*i,9ts the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. *pd6ls/ jux*ug .lbj*

  List the four fundamental forces i hr9czi/-.f.g6 vv mgcn nature.

  An object moves witho;* ta 6jh15;kcdqdf i a constant speed of 30 m/s on a circular track of radius 150 m. What is the ac;o 6d; *5qj tkh1idcafceleration of the object?

  The maximum speed around a level curve is 30d t1wou/. jrt yh 50cm7a3ht-b.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all o/ub. thj0m-ct 1o at3dwrh7y5ther factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicy vh tg p3/3+mni+2sy)w)dxbircle wheel of diameter 70 cm when the biketxd3)+rm/w 3yn g i+hp)ivb2s is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is l9k9 j9l yphx-ali95utocated 0.200 m from the axis. What htl5jpl-k9 u y9a 9i9xis the centripetal acceleration?

  How many revolutions per minute must a lfe dq+2q -7gbabc) d7circular, rotating space station of radius 1000 m rotate to produce an artificial gravi7 q2+q)-gdf7dbbcae lty of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turnx :nu n(rn04wf at 96.5 km/h. What is the centripetal force on the motn r n0x:(ufnw4orcycle?

  A 0.50-kg mass is attacyw2obew+ 1rq .p6 j,bohed 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 N. What is the maximum speed of the mass if the string is not to brp+b, boo e.w621yjrwq eak?

  A stone, of mass m, is attached to a strong s7snn,jhkj /y2-e/ nputring 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'e, jjs //u7k-nyhpn2 ns speed at this point is given by

  A stone, of mass m, is akb+3v9em jw2 mttached to a strong string and whirled in a vertical circle of radius r. e wjvk+mm2 b93At 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 acceleration of 4g when pulx8 auzii9 4(3ok /jvvbling out of the dive. What is the radius of curvature of the loop in which the planezv93oijv8ku i/bx 4( a is flying?

  A pilot makes an outside vertical loop (in which the center of the loop i)qs7kgcwy al)*4ofp0 obj)/y s 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 normal weight. How fast ip7)wl)s4 0c)qfgby o yj*oa/ ks he going?

  The maximum force a pilot can stand is about seven times his weight. What is th i k-xc0hmh3:b1e*imyk3vh*e e minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate 3vi m:10xhmy-* *kk b3ehhce iat a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal q5-dutp7cbju/ -qcj2gil),4:9hi lvqp/hp i curve with the tires on the verge of slipping. How fast can this car q)h qii4ijpdb7lg -,pv5t 2ju-puh9/:cc / qlround 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 cpa-lec k5v,r0hw a1,turve of radius 50 m with a speed of 20 m/s. The centripetal force provided by frikt 15,- hape,rlvw c0action 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 sjo*niuvu 454f/ypc*v peed of 14 m/s. What must be th fcj/iu*n54 v povu*y4e minimum 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 around a levelw k4m*o4kcd7-fuc8 gi curve. The coefficient of friction between the tires and the mfdgkw 4o*i-4cck8u 7road 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 bobsled to negotiateeeh,y, 4;jxf u a 100-m radius turn at 35 m/4ef,,ye u ;jhxs without skidding? (Ignore friction.)

  A horizontal curve on a bobsled 8t fvuxn) ,iyg h8/ra4s9g8aqrun 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, bgwb)cn40a mj3anked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m irt) cp*bts2+2 bbvif 6s 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 revolvm ., z,1oqxy ke:qmy/d6: jbnjing uniformly in a horizontal circle qj,yqe1jy, d6:o:mx m/ n.kbzof radius 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 accelj*e- 8rcuiq 7xerates 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) i -crqx7ej*8 u
(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 wjo 3 .t.mvgm2,fkkr+ $1.67 \times 10^{-27} \; kg$ 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 sta6ua f9 77duyzonding on the Earth, due to the7uouzdf 96ay7 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 between two masses is F. If the masses are hw0oqf+cr):p moved to half of p +wo0rq) hcf:their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what t8 bt3ks b1,uadistance from the Earth will the,a3k tbs 1b8ut 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 .d 6.p;vel4 iaugi3e d$7.4 \times 10^{22} \; kg$ 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 abuu;m4y ;vcmi f1xv;6p ove the Earth equal to the radius of the Earth. What ismuxvym1 cp ; 4fu;vi;6 her acceleration due to gravity?

  The radius of the Earth is R. At whahq8eip1kq 5 j 9y*0lvit distance above the Earth's surface will the acceleravyi1q qe5hj* l k9i0p8tion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a di4y lzsw8njj5+ ub *xf)stance above its surface equal to 3 times the radiusu*8+x y l54 jfbnjwsz) of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 :erjx8in. :2-qgspox km from some planet's center, the acceleration of gravity i.jq:oxpxen r- :s2g8 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 r1;n0ci7uh-pqga b8 cws 8ztd( . If the object is gh1i pbu w-(0znts;7 dqcca88 raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of q.t/.khl 4p fj g/mm,ka 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Ek,4 hgtkm/j. qf.l /pmarth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r axo:jcgg37 -atu1ii n.bove the Earth's surface. Whaja u.go i:3tci1-xg 7nt is the satellite's weight?

  A spherically symmetric planet has foummk06 xm0z3mhr times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Emmk06m 0h3mxzarth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Eartyxvbmnx);.dn.: jt l )h, and Sun all lie on the same line, with the Earth between the Moon and the))dvbtnnyj:. lxm .; x 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 transportez zhjcuj:m. +yw9i(r)d 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 6qok:w)tz* cxc3f:3t )ffkzs/nqd2 iEarth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth: kqfd3 2/z w)sq3z)fnotcft*cxi:6 k is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earq.0 cclh,yq3dth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth iqycqd,h30lc .s $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbih 7ezr :yjo14yt 230 km above the surface of the Earth. It is observed to have a period of 89 min. Wha714jezyrh : oyt is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, ha(ts o)6 f nowo73ir8uxs 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 orbit y89l07bps1b 1zqjiii s 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 orbitalj4i+uysh-sy7+ )a(+oiz+i f . bphtle radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long sysi4.+ioe bh+iul(jf) -t+a+ zpyh7does it take moon B to complete an orbit?

  The planet Jupiter is i /o/f w)u4sdmos c1h5$7.78 \times 10^{11} \; m$ 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 thvpvs o)21,/ +hhvxkthk8mz- ce average distance from Jupiter to the Sun? (The diszco k/h+ v1mxvspt,k8hv-h) 2tance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)