Is it possible for an object moving with a constant speed) 4x/ +)4xoc yqxe grgw*m/fmd to accelerate? Explain.wgg)eym /4dxo +*4 xfqx)cm/r

  Consider a particle mo 7mx:oh+hvs /uving with constant speed such that its acceleration of constant magnitude is always omu/7 hx:+shvperpendicular to its velocity.

  An object moves in a circuau+ 4ibqs9z w-lar path at a constant speed. Compare the direction of the object's velocity and acceleration vectsi 4+uqb-9 wzaors.

  When an object experiences uniform circular moe bpjqeh-,8jh da2s 4ab ;2ey4tion, the direction of the acceleratiep2e-jy dab44ae;hq 2 ,bjsh 8on is

  Consider a particle moving with constant speed such th5j- qry;2 8lz c5jorfxat its acceleration of constant magnitude is always perpendiculrr; zx 58y-jl2 cjfo5qar to its velocity.

  What type of acceleration does an object moving p0a*),zryhz rwith constant speed in a circular path exper, rypr0z*az) hience?

  What force is needed to make an object move iy8 s:1x8 g pvdbw16xdi*aasal9ez )v:ru mg3(n a circle?

  When an object experiences uniform circulx 269jimozs * ct6od.tar motion, the direction of the net forcxt6* ctomdj zs9 2io.6e is

  A roller coaster car is on a track that forms a circular loop in the vero6 4/ v+v,en iht v,:ryvvl:dftical plane. If the v,vvn fh4y:v l:,ed/o+ t6vircar 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 cirrg.4j2 kynql nr(w9kf s,vw- 4cular 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 for its speed ,n2 r-4j.k krq9l4 ywfvw ng(sat that point?

  A pilot executes a vertic8w jyw4w 2 ok:nb9s;d.ouu ks0al dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point,ksbw 0wyos8 n4 wd:.uk9uj2o; 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 curved j(18).2tx f6q xu tmkxa2xyx 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 radius r at a constant speed v. Then it goesg4rkp i ndn7,- around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second time, compare rikng d,n-p47d to the first time?

  A car goes around a curve of radius r at a constg;cd+*:jyvi 2 w+4/jtpqx pn ws i4;fkant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force onsfjv;d2g ;xk pt+ jn +* 4qpcwyi:4/wi the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curf.z, 75l ;xpbi 1f5kistg-dksco kz: 8ve of radius r with speed v. If the road is frictionless due to ice, the car can still nego zxolf k5;ki1. s5bi p7:,8kgc-tzfdstiate 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 b klu)n-b8 *vltr 5zo9x9x 7ouat the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for uol9z) u b9* o 7ltbrxkvx5n8-the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a q9 m1 0dbg n8c1x(;i-zkz)rab8 wwitwturn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionab; wzw )i1 0dnxw1z-rg8 bam9ki(8c tqlly "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object mt4ibcbm-d(+t0 (zub je o9,zmoving around a circular path to have both centripetal and tangential accelej4 bdcomim+tt(z, -z90 b(ube ration?

  The gravitational fo-(8(.z ckoskavapk 2f.voy 0 irce between two objects is proportional to

  The gravitational force between two objects is inversely p.utn/7ys:uml gu,o .wroportional to

  Two objects attract each other gravitationally. If the distance betwedmhl- -ccob8 5en their centers d- 8cob5chl m-is cut in half, the gravitational force

  Two objects, with masse kqz/2esm +.0aibu-qbs $m_{1}$ 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 mafoh4poh+ f3hpa)8 -c ksses $m_{1}$ 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 universal7y 7leplzbc(6: aa7go gravitation.

  Compared to its mass on the Earth, the mass of an object 3alt:-kknrgh/ t xx ecr2gd(jx:s733 on the Moon is

  The acceleration of gravity on the Moon* ;oy*efjk:68mey jhx is one-sixth what it is on Earth. An object ofojx8h 6ke f*jy;e *y:m mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface.bqmxnc6c ,hru*x 4jk8wr6 z0 , the rocket's weight

  A spaceship is traveling to the Moon. At what e-jl)qe;0 kqj k 53ld(m5klhe point is it beyond the pull of Earth's grave-mj klqqj)d l3(kl5e 5 ;eh0kity?

  Suppose a satellite were orbitin ircv 7ko8j7s4g the Earth just above the surface. What is its centripetal acceler7k4 sj8co v7iration?

  A hypothetical planet has a mass of half that of the Earth and a rac e3d:.z zwqt inh)h3.dius of twice that of the Earth. What is the acceleration due to gravity on the planet i q hn.zh3wc3t :id)e.zn terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-tmk c:t+v 9wep2p36h mpx+td*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 t *e:vdt+wx 6kpm9 3pc t+thpm2o the Earth's?

  Two planets have the same surface g;8nz 7/ssf 6qrd:chbk ravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planet Brh/dsfbs6;k7z8: cq n?

  Two planets have the same surface gravity, but planet B has twice the mass of plcad cbmug- 545anet A. If planet A has radius r, what is the radius of plan ud554-ac bgcmet B?

  Consider a small satellite moving in a circular ofrurey -/kvn- )3)*8gpn zxrl rbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital vell fve-8y3 p ug k-x*nnzr)/rr)ocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. elzk7*( dc6:ah6 5ra af+yqqzComparey6lzc5 *qaka:r f6+ 7dzeq(a h the two satellite's speeds.

  A person is standing on a scale in an elevator ac e fdvaf2)cbcx)x ews4k6/) ;ccelerating downward. Compare the rea6/s)x2) a b;fcx4edcc k) fvweding on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical patq o4k4bwn(/ oqhs around the Sun4q4k(oow/ qn b?

  The speed of Halley's Comet, while traveling in its elt;.jc: xsma9oliptical orbit around the Sum;a.x cjts9:on,

  Let the average orbital radius of afcf(s)z/+fyfb:zr a8 planet be R. Let the orbital period be T. What quaffz s8c/zyff(ar: )b+ ntity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the ;nfy 0p:o 9t6ptk9cbbsame orbital diameter as the Earth around our Sun. If thc6no bk;:b0f9p yt 9tpat 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 "astronomicalxf0v+xc4 3 fa/ gilr:e unit" (AU). An asteroid orbits the Sun in one-third off/ el 4axic0rv:+3xgf a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.+a rx)clc7en or:28 wsb1q,mz

  List the four fundamental forces in nature , b7c6wvv8zlk.

  An object moves with a constant speed of 30 m/s on a er42z ,gj;ky fv*ho9acircular track of radius 150 m. What jr 9 o*,kfzyvg4a2he ;is the acceleration of the object?

  The maximum speed around(mpu umr;qz4 t/ 7occlhb x7f(p8(r/x a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all o m( urqp8/ hmpt xo7ub(f74czxcr /l(;ther factors remain unchanged.)

  What is the centripetal acceleratio: yfjtbnltmr,od (-.1j8 fu,t n of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moj y:t tdf(fo,t.- mulnr81bj ,ving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the a6/8 mopjwj5nr9 ,,pk kmm+st d2bdxv( xis. What is the cent ( mk6sj25 nvm ,pdwx,kjordpt b/8m+9ripetal acceleration?

  How many revolutions per minute must a circular, rotating space staclb5*r(u ,b0r 6n jjr:uam4wm tion of radius 1000 m rotate (bc m6b5rr0lrwa,*un4:jmu jto produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around key7n4fd 9 aqbtl82i+xg j72n a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the m7kni2b yldet849q +nfj 2gxa 7otorcycle?

  A 0.50-kg mass is attache a8 en n li j;ixm1ug:i:ps6do3l.9t4ed 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 ti 4p9ie; :isxt8m loned6lg.3ja1nu: he string is not to break?

  A stone, of mass m, is attached to a stro) b; z;6drylkrng string and whirled in a vertical circle ofb;) d;zr kly6r radius 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 c70zhwp;) 6sjgclmw;strong string 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 this point is gg70w;hzcs6) wpjm ;cl iven by

  A jet plane flying 600 m/s experiences an acds,ysp*d+mf 2 celeration of 4g when pulling out of the dive. What is the radius of curvature of the loop in whichm p,d2 +yss*fd the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop (vgbm+c1pfrg +1 ,7 nsgij5vc 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 normal +n+p1ivrj,s 5(g mgfcgb1 v7cweight. How fast is he going?

  The maximum force a pilot can stand is abouf+w cqg)w*8ygvc 2,gltsh,a1 t seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can , aqc g ghwfv,)w* ylsct8+1g2tolerate at a speed of 250 m/s?

  A car traveling 20 m/fp vs:p(oj3,4d m (ndps rounds an 80-m radius horizontal 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 coeffo (fspmd vj,4d:( 3ppnicient of friction between the car's tires and each road surface.)

  A car is negotiating4k 24 kzi/zst5yx4vs y 8k*jjn a flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided bi5j4 zsky4 ykt82xknvj4z /*sy 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 ahus:17 6axg70 dap76gdwfzk ht a speed of 14 m/s. What must be the minimum coefficient of friction between the tires7gdf6h 71ks 0d x:pau7zgwa6h and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The ctryv9da0bg0 i,kd+he oc. vt :)7hk) roefficient of friction between ttvi00vh) , gkrhe bktco:7)dr +yd9a.he 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 angme5j8fabh8w + q( u8c) p0hp/n nw(juble is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s wab0(hcn+ j5n)8b8/p8wj uq u (ewpfmhithout skidding? (Ignore friction.)

  A horizontal curve on av16gyus4d. w h 5m.erv bobsled 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 radius 100 m,k(u hrbo8:vo2 y+ wnd) banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 mto-4qv0 (au ja is 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 ,bv-4zq 6cjxavrwq r2lo0t6aeb9. i*string is revolving uniformly in a horizontal circ.b 940zov a,2cv aier-wl qq*t6x6 jrble of 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,g y(auw;q)h- c9xmf9jlg26e 2m,oy u l a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of mux2(l9g2le;youw9-f qg jmc h6,y )aradius 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 . hf /bdigi+9c1tz4z uof 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 pe;q(g (tyrgf+srson standing on the Earth, due to the Moon? Th+; sgf r(tqgy(e 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 mass1 g+z5w9m;q7todc t0(a;wllct 9hzowes is F. If the masses are moved to half of their initial distance, what is m ltzwlwo 0;tho; 9c z(aq9wd+51 c7gtthe gravitational attractive force?

  For a spacecraft going from thy lunw5w2n,g0 e Earth toward the Sun, at what distance from the Earth will the,gl2nn5 uw 0yw 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 isw4 qsri o6kgu1 6+i3jv $7.4 \times 10^{22} \; kg$ 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 taa6ic/,1pb kyo le(h :he Earth equal to the radius of the Ea1kohc/6 :e p( ai,yblarth. What is her acceleration due to gravity?

  The radius of the Earth is R. At wh9nm-/ysb5df9*yltnc at distance above the Earth's surface will the acceleration of gravitymn5bt/ yy9clf-9 n*ds be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dis o3a9s kx7df:mtance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellitedf93:k sm7o ax, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km vn-m4a0dbol(0fkeb- ,la 9f w from some planet's center, the acceleration of gravity is 0 0fl wn9va-kbd,af-be(m 4lo $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surfam. b fzal99j8sce of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Eaf89 s zbmj9a.lrth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chatinkb2;w5cn l us;- km38oz.dnge when he goes from sea level to an altitude of 5000 m? (The mean radwc z;.kbum2k5oi s8ln-t;d 3 nius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite ofhc+p(wngyo /(b lt89 n mass 100 kg is at a point 3r above the Earth's s yt/9 n8+pwo(nlb(gch urface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and t7t78qjg0v4wncg ge :rokck5/ wice its radius. If a jar of peanut butter weighg5 7nco:ktg0eq8gcv/jwk 4r 7s 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 lie on thgn(66b4f, 6l/se ;qde tafik ke same line, with the Earth between the Moon and f666k/sifd 4;el,atqgn b k(e 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 Moon.g6btqnu3(i fn-ik)c2 hi 9 j(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 about thek+;zl kij9tn6 Earth (i.e., it just skims the surface of the Earth).lkjt6zk n+; i9 What 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 Earth (i.e., ig)m )nibnn s-zx ark+i.f86v:t just skims the surface of the Earth). How long dov k.mngx )sinfz6)a+8-i :bnres 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 sururlzbl- v)+d0face of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth +r-d u vl)bzl0is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter,/ao tre1g;ie 1a5l,hf has 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 Jupiwrv*g.fdg;s eo4 . ei.ter 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 radius 4apj ut4lib)dqc op 5(.a31ex 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 4.xecup4 o3 j a5aq1(bi) ldtpan orbit?

  The planet Jupiter ivuw4pby-7 ej5 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 tk6x x )vqiq iajdro69 n.o+,m(wz;o :Jupiter 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance fr). ;o owt(q+d6xn:ivik6qa xjzomr,9 om the Earth to the Sun is $1.5 \times 10^{11} \; m$.)