Is it possible for an object movingj .ubv/7++rnyube bfax3 1j8z with a constant speed to accelerate? Explain.3bbze + v.ju/8+uax1yfjrn b7

  Consider a particle moving with constant speed such that its acceleration of cdsjndm/ q; yoc0-jv 92onstant magnitude is always perpendicular to idy9cjo / jd2qmsn;v-0 ts velocity.

  An object moves in a circular path at a constant speed. Compare the directi:ft )b.v-q ;/:qd zdn ec7gyavon of the object's velocity and acc;fec vaqd:)7.tz: v- nqg yb/deleration vectors.

  When an object experiences uniform circular motion, the direction of the acq/q mq;9.dfkx celera;.qk f/9qqxmd tion is

  Consider a particle moving with constant speed such that its acceleration of conw 3pxls u-hxl:y73i)i stant magnitude is always pe:x3swx i-y i)h 7lupl3rpendicular to its velocity.

  What type of acceleration does an object moving witb ,qm5hr d2vtlaq9(cn+if 8fr( 1l5 x)6wikjgh constant speed in a circular px w r2r 65tvf5 fmcq i,dg)biq+((nkj1all h89ath experience?

  What force is needed to make an object moqjwbsz hoy4c2;yn be:d q7 08-ve in a circle?

  When an object experiences uniform circuf5;wjt3 w24r1 3:ouofxxk-eb uaptu7 lar motion, the direction of the net force isru:f ow4 ; fjxtpeauow3 3t15x u7bk-2

  A roller coaster car is on a track that forms a circular loop in the verticahh41+ ryy d-zjl plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value fo4jy rh-h+yd1z r its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circulrbzdts9oiay x*3g:p59h;po: ar loop (radius = r) in the vertical plane. If the car i9:h ;zdo tas*bg pp or35:xyi9s 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 y az: 5tg.hrn,ubc6s: follows a semi-circular arc until it is going straight up. Just as the plane:5ytg z.hb,ca rns6:u 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 qurui :t .5ht fqh)d67radius $r$ 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 sp8ytxml(l6p8 pgzo70 l/jfbs4 cyzz;2eed v. Then it goes around the same curve y 6;fmtx 2oby(l74c8j/zgpzlp08s zlat half of the original 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 a ezqlq( ng9r7(q:f1dt t a constant speed v. Then it goes around a c trqqnl1 (z ge:q7(9fdurve of radius 2r 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 wit) mj 2:/mm)4x wviulcjh speed v. If 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 magnitud/m)) 2w:vx lmj iucmj4e to

  Two horizontal curves on a bobsled run are banked a x8hw q0 kq.e*so eljz2 n*su7t,lx-)qt the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the xq 2jkh-qo *ws*08) tnlqz7xse.leu,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 isf qkj90sg/g(vq4(v .o0zmrut l ds (g1 not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "cl( v qogrl(u(tgfksd.4/mj00g9 z q1svimb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an objectoa8e: i 1oh4afbon6 -e2d27 djh +bwnz moving around a circular path to have both centripetal and tangential1b:7hahejo eodd2 +8w nb 6fo-2n4zia acceleration?

  The gravitational force between two objects is xtjdpj-w /db/nwc21, proportional to

  The gravitational force between two objeczu45 - c) 4hwjfre3okr:ud9aw mv+:kk ts is inversely proportional to

  Two objects attract each other gravitationally:n s34v -kgfay. If the distance between their centers is cut in half, the gravitat-afs:vy 34gk nional force

  Two objects, with masses-sak:t d (0fobl:5edj $m_{1}$ 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 makf3 :q(7la8c:t5x gi y7jy nbmsses $m_{1}$ 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 uu+b /lwcb;d,q *y/kq sniversal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moo)a6shj ugpmjp 7 p*g*r353tpyn is

  The acceleration of gravity on the Moon is one-sixth what it is on E r 0(p7lzkjdx(arth. An objec7pkjr0l(x (z dt of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from thvr(. fto9u0mz e Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond 7 xjyqa 5sf rv7uvi5,p.manbjw6l,*6the pull of Earth's gravity?l.a5af6 uji 5n7rbm v jyswpx ,v,q6*7

  Suppose a satellite were orbiting the Earth just abr4 z:-*9 iwd3jstvm.6cc d jj 3tloym8ove the surface. What is its centripetal accelerationo w9d :i jm33vjyr46*.lzjt smt 8ccd-?

  A hypothetical planet has a mass of half that of the Earth and a rc2x i4wrpn /,yadius of twice that of the Earth. Whc rx,piy4 w2/nat 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 one-sixth what it is on Earth. The r+rah lg9 6ro7qadius of the Moon is one-for+o6hr9lg q a7urth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface8w6nu /hj3j5tb2 dpnw,c2l nw gravity, but planet B has twice the radius of planet A. If plab58hw3w dntc pu2n jl2n, /jw6net A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B s1edg2 . 5hgl+1dxn;fwbv,ca has twice the mass of planet A. If planet A has radius r, what i nw; gval+f1d125ghsxdb. ce, s the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sphkc--dbk fs15u erical planet (mass M). Which expression gives th 5f-bkksuc-d 1is satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit.*z 3hgkoy(+ dt Compare the two satk(dzh+oygt*3 ellite's speeds.

  A person is standing on a scale in an ele/dyw-xe+0cqhc5rf do* 9r -vpvator accelerating downward. Compare the repq -+v 0/ 9*d5r-cydxwh oecfrading on the scale to the person's true weight.

  Who was the first person to realize that the planets move iny1cc4(g, cn,jd1tnc 0uy nh j1 elliptical paths around the 0n1g4 cjc nty1(ny,h ,dj1cucSun?

  The speed of Halley's Comet, while traveling in its elliptical orbits;( coda b*6mb around the Suno mb d*a(6cbs;,

  Let the average orbital radius of a planet be Rctj k,2t qvi ;7-fc:mflju -; nis o.w26ll;ar. Let the orbital period be T. What quantity is c :-j;s cqrmt o7ci u6tal,l;kn.-j iwl2ffv;2onstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in t1/gl .t)lzlkw he 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 ww.) zlgt/lk1lill 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 "astronoluar j.y4r 7 h5k:oe-mgq am:6mical unit" (AU). An asteroid oremq a64.rjaum hr l:7:o 5gk-ybits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. */thnxss1y7ozn 8d-x

  List the four fundamental foy klqkne)psp8ta-18 1rces in nature.

  An object moves with a constant speed of 30 mx1ukwz5l 8t t,l/wq h0/s on a circular track of radius 150 m. Whathtwl,0xkt1zuq5 w l8/ is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. ;wq,5vmij:be:b 9s vsp/ 4kjh What is the maximum speed around a curve with twice the radius? (mqj e:bj/ v, bks9 5hswvi:4p;Assume all other factors remain unchanged.)

  What is the centripetal accel fbv:cjruzf- -w);vbum7k0 .deration of a point on the perimeter of a bicycle wheef- uv7rbf w)vcb. du;:0mkzj-l of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is 0aft(irhh8gw2m 2b8w located 0.200 m from the axis. What is the centripetal accg2h8hti mfr(bww0a 82 eleration?

  How many revolutions per minute must a circular, rotating space station of rad)x0o qcq t(w mjd(;6xqius 1000 m rotate to produce an artif qq wtc6; m(qx(0jxod)icial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass+)ecjhtk. kd((orh5u of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorhh5 d)c+e kk.(t o(urjcycle?

  A 0.50-kg mass is attached to the endb jsar7.6jbu:m yr0 h; of a 1.0-m string. The system is whirled inrmu:bj6say;hbr 0.7j 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 i3ksbo/64:al+l q x9lep2zkh tn a vertical circle of rha9qkllx2lo /3p: +ek bz64 tsadius 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 is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical cl*s)ferza+dm4)c.ccw ,7o hoircle of radius r. At toc+,od e a).)w4fzrh*7mclsc he 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 pulling out of bz5ty 1z1*:vzcyi i0c the dive. What is the radius of curvature of the loop in which the plane isc5 b1c i:*1zzvi0tz yy flying?

  A pilot makes an outside verti 2te zyavmv3jkw:92n01 t7 aoical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he ijkvet3: 2 7w1y02vt9o manazis pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven timd 7 4)lr4u 9oxcdut)bxes his weight. What is the minimum radius of curvature that a jet plane's pi)794r d)dxl x cutu4bolot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds 7 o(klhb 5ztjf8 8wpr+an 80-m radius horizontal curve with the tires on the veb7(+r l kth5zp 8owfj8rge 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 curvevx p6 aa8,da:b3+ mr jryf5f4dlth)b*i ei;d/ of radius 50 m with a speed of 20 m/s. The centripetal force provi r8vd,/dhj5 ftia;y falbmre:a6 + 3i4)bdxp*ded 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 e uuci: c(dl6gn* ux+gjr9)5c m at a speed of 14 m/s. What must be the minimum coefficient of friction*guxi5u 9ecnc)ju6(+ :dcl rg between the tires and the road for the car to make the turn?

  A car is moving with a ( l-kvte:k) ;jwgokws6*b0 ghconstant speed v around a level curve. The coefficient of friction gj)btvol(kk*-wh0g :sk w ;6ebetween 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 Olympic bobsled to negonz51 zyt / .qn hbbzr0i74a/ak)7p ffotiate a 100-m radius turn at 35 mabfh7/)bzo0 fr5a4 1np nkzq 7z/iy. t/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banke lh+vbjg5lk4vw z(43 ys3lo; cd 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 o*se3 v+2-pw,x qxwzxs f $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is qx t(jppb 9djb7f0.k,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 xwet shmq-a6n9(2ik- circle of ra-xs 6n i2qw9h(kt ma-edius 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 accelerates at a uniform ratrjy rmw01k,8 re 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 bl81,wrkrmyj0 ranks)
(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 ) l:vz+y0 oevxat0r0 p5j 27lsqgtxc;ypo:+c 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 gravitatioo6iphh9;c6ixr jav/9m9 mq s0 ewz,p,rv *ly6nal force on a 70-kg person standing on the Earth, due to the Moon? The mas;v,6oy 0 v qr p*w9i9hjhar66ie/,clmzms9x ps 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 mwj //tcu.qgz gyll ia (ftm01sjt2 *6)ry*w/ soved to half of their initial distance, what isyyf)1wl utisj 2tgtgz6/lwc .**qma( rs/ /0j the gravitational attractive force?

  For a spacecraft going from the Earth toward jp yfio3) p,e:the Sun, at what distance from the Earth will the gravitational forces due to the Sun an op, f):3jpyied 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 5/8jzlk8qq gghuat/dg 3e5 4uis $7.4 \times 10^{22} \; kg$ 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 mrk faeu vej2v6:)e,:b+e a,z"space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration dueeu ,ef+,v6a: mkb eve zj):2ar to gravity?

  The radius of the Earth is R. At what distance above the Earth's s a2z-9o hrm3ah,.g xnvurface will the accenv.xa 2om- r 93zhg,ahleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 fy5 ta8 a9w6qaw,n,6bdcpog4 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acc9,6 f,5 68yowdqp4a nt gcaawbeleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's centericiy 6i-e+8ym ga9*mx, the acceleration of gravity icy-giy9 6ie+xm i*8mas $32 \; m/s^2$. 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 radiuws j/k860i1jvsq+h rc s r. If the object is raised to a height of 3r above the Earth's surface, what is0v 6rqk 81cs+swjhj i/ its weight?

  By how many newtons does the weifys ,jj.4yi8nght of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (Th8y4fi s.jnj y,e 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 above the E; szp7 dhdp0aoj aj;3dd6sn8 2a ds7;zpj3 dp8da 06;sh2d ojnarth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass anlfmp0*dij.d2 pf ii ;1d twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the sip idpdj fi2;.1*lm f0urface of this planet?

  During a lunar eclipse, the Moon, Earth, and w81s)s dty h4nSun all lie on the same line, with the Earth betweetnwd 8ys) 1hs4n 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 to the bcy aviv)jen;/4w69gMoon.
(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., iqob 6ck r:73,mx /m-ny( 9akjwdu- rbzt just skims the surface of the Earth). What is the speed of the satellite? (The mean3mbaq n9/ , ckzyd(bk67u-jmro:wx-r 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 spj-0l 7izwj7 t+ k8vsbymgv +9kims the surface of the Earth). How long does it take to mabi+ms7wj 9k0 yz-v+p jvg87ltke 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 oj 51r bb8siv. 2*plz.9hvwa7prn4z l xbserved to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth i.n 8zxhb4rp b*lla7 1jsz2prw.i59 vv s $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of q9.xvn)0(5c euw tucdf*es8j$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon o.3zfiov xvb3d ij4 i57f Jupiter 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 has orbital radi3v6qy 95wq vulxq j99qus 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 complqqjq6 5vx uwyq 9v39l9ete an orbit?

  The planet Jupiter is (09b ofemsl; ;cr/m*mjg:uwpo/usk 3 $7.78 \times 10^{11} \; m$ 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 Sum8z; b6k:pm k l*odue2n once. What is the average distance from Jupiter to the Sun? (The dist zkoe;pmdblu26:*8k mance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)