Is it possible for an object(rqf 5do bkm;+ moving with a constant speed to accelerate? Explain.5(; roqf b+dkm

  Consider a particle moving with constant speed; vo r)(arx.uu such that its acceleration of constanaru.xr()uv o ;t magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant spee; 3 hnwuoi0uu brz+d28d. Compare the direction of the object's velocity and acce 2 i;30dh+zuuwbronu8 leration vectors.

  When an object experiences uniform circular motion, the3zltt.:/r*hsppd3 sml li9dev)2 l 7 l direction of the accelerastlll:t vrmpe/l *33 s29p)il.hzd7 dtion is

  Consider a particle moving with constang6;cz;p + +y1ftuuxlot speed such that its acceleration of constant magnitude is always perpendicular u 1y+tczgo6x;;fpu + lto its velocity.

  What type of acceleration doe y* v*2mz1jxr4nx il/os an object moving with constant speed in a circular path experien zxiyr*o1/xlv j*2n4 mce?

  What force is needed to make an object move in a cir(3(lbb h +q nhz7zweq5cle?

  When an object experiences uniform circular moti e f1mqp.s4yg2on, the direction of the net for4.gf eqy1ps2m ce is

  A roller coaster car is on a tracck:b)o-i gd4b7,6yb wgwl0p zk 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 centrioylgwkb w)-bp:0i4gbd7 c6 z,petal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loopy+rs8cd42k8 n9,g0tuwcf 2lvqdoir4 (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the 4dg2c0ti89v2q,d rf wk nuc 48+yrso ltop of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi,pkpio uy;0i:t6 j(ym-circular arc until it is going straight up(jt0iuop y6y :k;,imp. Just 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 of (c/jpc +ba w*.zdo-txpl1 5 bcradius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radinbc8i.-cd k1vbn u 1b9 7ls9tius 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 the curv .-tbubb7 vksid9 nn9 l8cc11ie for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. o7ixg qa sg+t- /0grj(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 curve, compared tosjog g r- i+ta7(0/qgx the first?

  A car of mass m goes around a banked curve of radius r with speed v. If th n vjqvst4nsh+)4:z0y iq* ao4e road 0 v:a* s4izsh+4q n tqo)v4jynis 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 to

  Two horizontal curves on a bobsled r (e:w0 gaax fauk95m2hka4jerv8kr) 6un are banked at 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. What is the safe speed on the larger ar 4r9ke(g 6m8a5:h2xj vw )ku0aefak radius curve?

  The banking angle in a turn on the Olympic bobsled track is not consd okya*5-kyps;6t*nzc7 s09dq cu j;rtant, 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 do th5n yj;cp6 ;adkt*z-ukr0d9qsc7so y *ey do this?

  Is it possible for an objetmgy1 23ggdj;ct moving around a circular path to have both centripetal and tangential accetjd;1ggm yg2 3leration?

  The gravitational force between two objecta ;ov ipq n g68:i*7v3eum7ytos is proportional to

  The gravitational force between two objects is inversely pro1bc:rm4s by q7portional to

  Two objects attract each other gravitationally. If 46) xhstme:+ hwor 2io;wwo-nir:v ( kthe distance between their centers is cut in half, th:+ (i vrwwt wmo2h4:hroikneos ;6x-)e gravitational force

  Two objects, with maugo61z 26svt i4lsh h/sses $m_{1}$ 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 masks( tr4qt p+1ygyghp;t.q6 x(ses $m_{1}$ 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 univers m1 o5d:s2sopm2a5ghbal gravitation.

  Compared to its mass on the Earth, the mass of an object on txc9a(7p y l.cdhe Moon is

  The acceleration of gravity on the Moon is o-;0fed *oqhy ht*f3-;hxlk5 jh/ m lysne-sixth what it is on Earth. An objyqlhx;dlfk;h3h h5* -fts0y *-ej/moect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, thsn ,(;a1 qpeuoe rocket's weight

  A spaceship is travellhyo)cu :jk)-rh t;9 ning to the Moon. At what point is it beyond the pull of Earth's gravit :u )rhh9kytloc; )jn-y?

  Suppose a satellite were orbiting the Earth just above the sgm+p /fyt.,4x9sh.j jqzsin. 5k clz3xy; 5jaurface. What is its centripetal ac 9x;.,3zns5j 5mk.ithl a 4/jpxg +qzysj. yfcceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius dzf:;-4l9:okl 9yt sgf/ 8l zmkfk*lhof twice that of the Earth. What is the acceleration due to gravity on td k4*y lzmg of:sflz k9ll: /tk;89hf-he 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 isnmy ;nsoqu- +am--a3i on Earth. The radnqa-s-3oymu a ;-+ni mius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planepfl1* c uafhzh()(u u -3om9wht B has twice the radius of planet A. If planm(fpu1h fz3u-lohha c ) w9*(uet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice vc3 flx3py i(e.9zbr4the mass of planet A. If planet A hayi94xcf.z3b p elv(3r s radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbil80-eafhwd f q (;rj5it (radius r) about a spheric-jwlf05ri (ea; 8dh fqal planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twicm+qb/oy 2xr :se the mass of satellite B, and rotates in the same orbit. Compare the two satellite' qrm:os+b2x y/s speeds.

  A person is standing on a scale in an elevatobg7n.d .u q(cg 0/ohphr accelerating downward. Compare the readidh/. gpg0qhn.c7 uo( bng on the scale to the person's true weight.

  Who was the first person to realize ;q j71xun oja (f+cdjyy)7h- zthat the planets move in elliptical paths aroun y( ;q)c7ojnyjzu x+1-dfh7jad the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around the t a5juv x*vz6;fuyo1+ 1u tua6 j;+zvy f*xo5vSun,

  Let the average orbital radius of a planqjw-v 4)gqs- uet be R. Let the orbital period be T. What quantity is j4-ws qqu) -vgconstant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda,5 kg84de4timwe3sp 5it1b hl. with the same orbital diameter as the Earth around our Sun. If that star haste4ig4d8m k.1be3 s l5htwi 5p 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 fro8zudv z;* h3qx-ktqh.m the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distz .*zhduqvt3h;q xk -8ance from the Sun?

State Kepler's laws.7 r602 dya-y;yuw,d;:h k+ldrdexjdx

  List the four fundamk +doz3q fcb35ental forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radif0oa-1zpga3sr8rp :n us 150 m. What is the acceleratio pno:1-3 0rap8zrf gasn of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum speed 0fg2(pbsvk((pi zc8y around a curve with ysgpkzfvp (c(8(b0i2 twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleray7 k -ng8jtn6:omr/ ypwp:1e gtion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 o/n 6ymnk:pw trg p8e:7j -yg1m/s?

  A point on a wheel rotating at 5.00 rev/s is locate4z lq-ftb (+/f6v l r;yb4qtccd 0.200 m from the axis. What is the centripet4v4zc6(t tqbfqc;lfy+-l/br al acceleration?

  How many revolutions per minute must a circular, rotating9hkp;+ w3k sxt lg,hi6 space station of radius 1000 m rotate to produce an artsg wkt+xi,lk6hhp9 3; ificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. j/*. xn q5myvy It goes around a 13.7 m radius turn at 96.5 km/h. Wqm.nyy x/ *5vjhat is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0- *nv xtx6sm9l+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 totmn*l xx +6sv9 break?

  A stone, of mass m, is attached to a strong stric dzlqxig )(9*h 3*pbing and whirled in a vertical circle of radius r. At the exact top of the path the tension in the striizql*9)i(3 x*gph cd bng 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 strinixy 8lqo2s-y bz/h9./j zgi(ag and whirled in a vertical circle of radiuy 8/iyjh/l -za.b2sgz9o( qixs 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 given by

  A jet plane flying 600 m/s experiences an acceleration of 4g wheg8e: ex)u 8ik 7*o +zhwuy1yftn pulling out of the dive. Wyizh fuk)uw7 y: 1e* e8ot+x8ghat is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outsivp* p s)s0rconxc za680q yt84de vertical loop (in which the center of the 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 normal weight. How8sx a) s tzp c0vpy8qcrn6o40* fast is he going?

  The maximum force a pilot can stand is abopy0tcr8q41 n l+lsy- out seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dioll1+y0-crpt qnys8 4 ve, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s roundx qldr .r-9t:es 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 coefficient of friction between the car's tires and each rotdlr 9q. r-ex:ad surface.)

  A car is negotiating a flat curve of rad yokv9t+tlw y805nhn ,ius 50 m with a speed of 20 m/s. The centripetal forvt50,9 l htwyky8 on+nce 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/s. What mustixya3: .ei .oy be the minimum coefficient of friction between the tires and the road for the c.y:3a .yoiiexar to make the turn?

  A car is moving with a constant speed v around a level curve. The coefficqnsiko j-vc+n;bj*.o,ebp 8:ient of friction between the tires and the road is-noe ji . n+*c ,;qb:jpsbo8kv 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 td l*j wiih,4w3 :e;mnpo negotiate a 100-m radius turn at 35 m/s without skidwl:3 4e *pnimdhiw ,j;ding? (Ignore friction.)

  A horizontal curve on a bobsled run is banke9q/2v ,kwx d8df2v ngrd 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, k1fq k vw*jx:apwuw fr)p6,6,banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankg1i6o ,. iyhvdrq v,d5ed 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 en7ccss4fwy 4,yo1h 8l6 6mtm/k g4 rjygd of a string is revolving uniformly in a horizontal circle of ras, yj4rw m/8 lmg 4yh4ctkyoc g66s71fdius 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 tuvb+xx qnhcp-u.cc8z4o pi4 s5r271yhe pit area, 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 numeric qcx4.csvr5c xi81 hu 2po7ynp+z-4ubal 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 of m7 o;z m*sa kruxz rzp.c+)6l+cr(o9 edass $1.67 \times 10^{-27} \; kg$ 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 onz: c2-)v elylm a 70-kg person standing on the Earth, due to the Moon? The mass of the M)y2vll: m-ez coon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force be) hnp:ru(56gc qkeka4 tween two masses is F. If the masses are moved to half of their initial rkq 5e):h(up4k na c6gdistance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward t * nkrf 13. 7wsxvbi;-uulhus+he Sun, at what distance from the Earth will the gravitational forcs7*lvb 3-sfu1u+;ik.n wr uhxes 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 i fxr7gnjj; 4t,4au yr:s $7.4 \times 10^{22} \; kg$ 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 twp6p 8;i iww(4i9lg hwhe Earth equal to the radius of the pi 8w hw9pg( ;lw64iiwEarth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Eartha6ekwb6 j)t5z 's surface will the acceleration of gravity 6w jzta6ke)b 5be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance a/x pqlr:do ,f4vxdz-g v0tf /;bove its surface equal to 3 times the radius of Mars. The accelerxo0vfd,dr:l g-z x;/v4pqft /ation of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from sork* 3yi,lu )pdme planet's center, the acceleration of gravity iu)*l p3dik,yr s $32 \; m/s^2$. 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:fmvtseqw pn*./vkk09k qe43haep/) has radius r. If the object is raised to a height of 3r above the9ak03 q* e. /qkv4nv)ewfhs:ktm pe p/ Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when hekh fn v0k9yv*9s2-a nvitz3)o goes from sea level to an altitu3h yz09)kfivo 2 as-9 vvn*tknde of 5000 m? (The 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 tqi+uk/0d +onEarth's surface. What is th/i kn+duqt +o0e satellite's weight?

  A spherically symmetric planetcgel*egx( yd3:oi2 4k/h at k( has four times the Earth's mass and 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 surface of thisogiyx( /k etg( 4*hc3ekda 2:l planet?

  During a lunar eclipse, the Moon, Earth, and Sun all l dt8c30 xb*pjdie on the same line, with the Eart xjd08*3t cdbph between 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 t q8f f.k(i4nj h 4i/t-yadp7l,vkgt, fo 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 Enfg k-yeeok8y p) (9*yarth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the ynyoeg f k9 k-8pe)y*(Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just skims the:i3 yi95q8 5xmihgtdjm2uzr/ surface of the Earth). How long does it take to make one reh5: 9imy3/rqzi ixm u 825djgtvolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular 91txs)f/.frh k(wtng orbit 230 km above the surface of the Earth. It is observed to have a period of 89 m)kx9hf1gtsftr w/( n .in. 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,g5wbtniv(5l 2j36aoc 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 Jupitz(ij:.d4hqc e er 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 ri4(lch fv8eg v8dqvps*w g8, (, 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 an orbivs8hif lp4 vd q*gew(,8(v g8ct?

  The planet Jupiter is t8; l/4viu xus$7.78 \times 10^{11} \; m$ 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 the avera/mc 3x qbx1pc89k.+2rt aqquqge distance from Jupiter to the Sun? (The distance82ak1bqmtcu cpqrxq 3+/ x. q9 from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)