Is it possible for an object moving with a constant s )3cjzbtz j5h3peed to accelerate? Explai tjbh5z3)j c3zn.

  Consider a particle moving with constant8i6ie y+9li zg speed such that its acceleration of constant magnitude is alwaysi8zi+i6g yle9 perpendicular to its velocity.

  An object moves in a circular path at a constant speed. ;7f+ j :0xibxfx4ru, voczni9 Compare the direction of the object's velocity and accelerationx,rju4zci x9o ;fv7n+:0f xbi vectors.

  When an object experiences uniform circular motion, the k*p k6reh-dd be8,d6b direction of the acceleratior b6dheek*,d6bd8p k -n is

  Consider a particle moving with ccax0:zynpu httf19 8 5onstant speed such that its acceleration of constant magnitude is always perpen0:h af9c8 1t5xpyztundicular to its velocity.

  What type of acceleration does an object moving with constant spkk7iw1hn+:ob eed in a circular path e+wk1k no7hi:bxperience?

  What force is needed to make an object mov4e2hldo3 tmx /e in a circle?

  When an object experiences uniform circular motionto)0 hlzwx *qawj52 /v, the direction of the net force i 2twlv) hzo 5aj*qx/w0s

  A roller coaster car is on a t g: -buk2sg4xzrack that forms a circular loop in the 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 cexgg-4bz u 2:ksntripetal acceleration at this point?

  A roller coaster car (mass = M) is on a, w6u xuz+ip fr/o )xq,8kgi5p track that forms a circular loop (radius = r) in the vertical plane. pu +qk zxo/8fiwi)rp 5xug,6, If the car 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 follows a semi-circula5f3vgr-v z stu.2 km2nr arc until it is going straight up. knf-v s 2v2t5zugm. r3Just 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 spp7wn v7 owu((k1d8z of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radimfe g 3c,dw-w9gyt. b/us r at a constant speed v. Then it goes around the same curve at halb-tgywm/3g cde f w9,.f 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 at a constant speed v. Then it goesxlfj ry46v7pl ..90 tzjpmgz* around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second cuy pm0z9t x 7zjvl4.*lf 6pgjr.rve, compared to the first?

  A car of mass m goes around a bank+qw30+gwth f6afcb r.ed curve of radius r with speed v. If the road is frictionless due to ice, the car can still n.+b3 f6g rtww+fh0aqc egotiate 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 are banked at the same v;7xlh fj1gbe 7z/c6uangle, but one has twice the radius of the other. The safe speed (no frictxuh 6fe;/7 glb7z1jv cion needed to stay on the 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 is not cons- uf1 sxptv/4zf+xk-h wa2xw7tant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Why d -vw1 pwfkz+h x7f/-xxs2t ua4o they do this?

  Is it possible for an object moving around a circular p60ry )ja2b7 ucins,ddath to have both centripedbasn7 )r02,yu ci 6jdtal and tangential acceleration?

  The gravitational force between two oyx lb)bq6vx209fd u3f bjects is proportional to

  The gravitational forcyl+ retjuzfo)0u:1 4kw0 nwq3e between two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between ther17.6xcbpsp ydv82 8lnlo8x zir centers8y7bl8p6dzrsp lvc8nxx1 o2. is cut in half, the gravitational force

  Two objects, with masseo1/ad +ja yvip,zf4 8ks $m_{1}$ 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 fpuhu.5.js 0h$m_{1}$ 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 gravhci4 n uw/)ib5itation.

  Compared to its mass on the Earth, the mass of an object on the M8l *,sxmj w b9cdb5v8u*c( guzoon is

  The acceleration of gravity on the Moon is one-sixthc6)*s k jgeexeo.p2a) what it is on Earth. An ob.6*j eg pesc2k)a)xoeject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away froics 9c/xt 3;tg9 yoe; n0ks3unm the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond :67q6.d--j he3k sibyzbnxx dthe pull of Earth's gra-j deykbn63xi6s.qzh7b x d-:vity?

  Suppose a satellite wefm syblq a6j,l7jwe440 2fun5 re orbiting the Earth just above the surface. What is its centripetal accelenq6eb,jy 4 ua2smj 5wl7f0lf4 ration?

  A hypothetical planet has ,afkp jy e::zju go+3.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 j, y.+j3pgk: fzuoa:e, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is onzywu;pen65g 1 nbtb 16e-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What isu5y nnp1b6g b61wt;ez the Moon's mass compared to the Earth's?

  Two planets have the same su:qaee zu:.9pqrface gravity, but planet B has twice the radius of planet A.az upqq9 e:.e: If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, jp9l+.wi .5 +pfd nbglbut planet B has twice the mass of planet A. If planet A has radius r, what is the radius fwpibdn 9 g.5l.lp++jof planet B?

  Consider a small satellite moving in a cirukft .,67urv tcular orbit (radius r) about a spherical planet (mass M). Which expressionk uvt7f .ru,t6 gives this satellite's orbital velocity?

  Satellite A has twice the mast;kq *:6 w krqjg jm;.4u.rfygs of satellite B, and rotates in the same orbit. Compare the twyq.g jwf6k: k rrt*;j4;. muqgo satellite's speeds.

  A person is standing on a scale in an elevator accelerating do .+uw8zv-id kfm,nw (+, pfkinwnward. Compare the reading on the scale to the person's tr+iwid,fkwn k( , mvuf8-+ z.npue weight.

  Who was the first person to realize that the planets move in ellrmvj1l515 nhqrp er0e; ox28y iptical paths around the Suj 5oe2vrl1r8q m pe xn;0hry15n?

  The speed of Halley's Comet, whilw;c9 pzq,c t0ne traveling in its elliptical orbit around the Sun,tnpw0 cqcz;, 9

  Let the average orbitachl0o2 xz k9l(l radius of a planet be R. Let the orbital period be T. What quantity is constant for all plal02ck( lxozh9 nets orbiting the Sun?

  A planet is discovered to orbit aro+ 9k b:pqn.up w,;k7okv wjc: bya.uh8und a star in the galaxy Andromeda, with the same orbital diametebkh u.7 , +qyjb 8nk9uc;pk::wwap.ovr 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 Earth to the Sun is defined as one "astronx*sg4y6g9(ny- b64t wqza fhvgl8 9olomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from thgy 4t(fogb9 ly68lv4z9w n - 6sa*xhgqe Sun?

State Kepler's laws.h + w0 t nabulyl1i9ul+ji4rmn.bo9. 0

  List the four fundamental forcesek(eo *q4 cbl9 in nature.

  An object moves with a constant speed of 30 m/s on a cire*tk-i ecqb)5cular track of radius 150 m. What i *q5)c-kbt eies the acceleration of the object?

  The maximum speed around a level hah w3k7;u*f;q eqld* curve is 30.0 km/h. What is the maximum speed around a7hu *3kwd q;fl he;a*q curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on tpgx ;i/5ox,g*oxs p r5he perimeter of a bicycle wheel of di5xgs, ogrp;xop/*xi 5ameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. 7hdw e2/4iu se What diwe742s euh/is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of rabkmb:q*/a oc:4ur-e4v s ptp *)tpcp8dius 1000 m ro k8cb*p) brpa4/o t -sq:ep v4upm*c:ttate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 2 x ibxrup58tzf*z0-(h50 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripet *tzf(xb urhzipx805 -al force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is o-.b; , nhc4,uyg ,wp.wpet0(a ajsktwhirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. kapy. a n e0hsj;,cbw.(t u-p,,wtog4What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to ksxg ce3a, b,o- m/7ona strong string and whirled in a vertical circle of ng ,e3bxo /sk7ma,-ocradius 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 km :j 0xcoa3j;and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weight. The stone's speed at thi:0mja;ok 3 cjxs point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulli*l d2goei /9ning out of the dive. What is the radius of curvature of the loop in which ti2n / e*glid9ohe plane is flying?

  A pilot makes an outside vertuvp1 u4z9-q zhical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushinqvhz-u9u4pz1 g 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 s,a2/9laou zbxqgter h( (pb0-even times his weight. What is the minimum radius of zagb 2/lr9b(e-qpo0 h,(aut xcurvature 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 horizo5d.t e8 0hsyvvntal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient of friction between th.d5vest y8 v0he car's tires and each road surface.)

  A car is negotiating a flat curvefki+q/ (2f j ;wnc ,6fd5jogkm of radius 50 m with a speed of 20 m/s. The centripetal force prfwm2 ( k6 +c5ifdg /;nq,jfkjoovided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of 0uz9eu7cyowbz:+g l,w2u /hgradius 50 m at a speed of 14 m/s. What must be the minimum u9y+ g0gzclh ue7, /wzuow2b: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 level curve. Thnqey0 d4vr8ifhst27;xo(h c 0e coefficient of friction between the tires and the road is 0.40. What is the minnx0f et4vd 728hiqo;0hrs(cy imum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required we2fbi c-f0n4 for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s fewi0c4fnb- 2 without skidding? (Ignore friction.)

  A horizontal curve on a b *ypkjoz, ck)y +7x6gpobsled 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 radiuprbj;(m4 wcm 2gd*8 ptn:/knfs 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 79pg wjp1ld0c $45^{\circ}$. 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 cimw cq. vk70x2vrcle of radiu0. 2vc xk7vmqws 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 w;2dt9o4qdff 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 wd2;f9q fd4 toblanks)
(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 p f+w3giv)f,a pt 7t7j+ ed/)itgwxs7q roton 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 person standing y22pcwb9f2z iy k4)ye on the Earth, due to the Moon? The mass of the Moon i2fbz29k yywy2 pci4e)s $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational att sw:.2kc jc3bvm8ge x0ractive force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitjsccg8 v:0 .e3wxm 2kbational attractive force?

  For a spacecraft going from the Earth toward the Sun, at wha/dwcnk/ 2.ueit distance from the Earth will the gravitational forces due2//iu nk.ce wd 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 8. q2quc5f*)bmxrsmn$7.4 \times 10^{22} \; kg$ 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 fop hyf ;ntjsl k59)43o8fhn htlupu y3x 8s.)/yr a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to 5pu/yy 9j;l3o.3yshfnfsuxt t hh8)4 lpkn) 8gravity?

  The radius of the Earth is R. At what di v1:wx8pkv(jyfmdgn) 5/qb) lstance above the Earth's surface will the acceleration : jlbq)x gn5d1 8wvm( /)pvkyfof gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 time3hgp u e:w qh9hbm(m v8yja644s the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceuejvw(4h hpm: qgb694hm a8 y3leration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of givt:wkcj1g,d a,2+ fq ravity,,qi1twv f kag2+ jdc: 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 l78c4 ueaae w83milndb*e6: qthe surface of the Earth. The Earth has radius r. If the object isanab84u 37we mel6c 8q*ei:dl raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the wect 8*c 7yqadyj p-2+3h;+lbpikfed2jight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radid 7cdh +ef2*i-tp ;ybjjp cqy+a8l32kus of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satelli 2.h8 ed(+nt.3p )orbjek v/p1gpf fskte of mass 100 kg is at a point 3r above the Earth's surfaceptee f+ohj3fnp g. k2dr. (8b /k)1psv. What is the satellite's weight?

  A spherically symmetric p m1kloiq7;qp/7lcpz te86 1fz5r dl 3ulanet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 irt7ol 15p6 ;q3 7zfke 8mlczpu1/dqlN on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Ear1) 9sth. dvaqlth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The M1hdt)vs.l9 qaoon 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 Moo3yj0eitb) cn4 n.
(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 ab uvy2ckt if 3ck kc:*6rue4.l7out the Earth (i.e., it just skims the surface of the Earth). What fk7yu .k 2r6vcl3ic4teuc:k* 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 cizpmc.5b 5i.l,5 zj0ghxsxu9ircular orbit about the Earth (i.e., it just skims the surface of the Earth). How longz jl zxg95bu50i.mcpi , sh.5x 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 above the surface of the m*7h8ekz. i( w9ocyhdEarth. It is obserc*id.e kyw 9o7mzh8h( ved to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, hasz v)nr+a3jfe hwzykq:17, ua. 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 radius ofd f u:-sbdyo15 $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly .m*gn5n n*o pwcircular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takeopg w5*.*nmn ns 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 9c giewwkk:u1* r-tv qwl12v:$7.78 \times 10^{11} \; m$ 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 rqs5r3n* i6bsis the average distance from Jupiter to the Sun? (The distance from the Earth t*sr6r iq53nbso the Sun is $1.5 \times 10^{11} \; m$.)