Is it possible for an object 2p/ be *a(sxc3bani5imoving with a constant speed to accelerate? Explain.csi(5exna 23* /ibpab

  Consider a particle moving with constant speed such tf) *a) mgtpwx7vfdu7:hat its acceleration of constant magnitude is always perpendicular to its velma:*df) x7f)tguv w7p ocity.

  An object moves in a circular path at a constant speed. Crf+vow1 ;gmi4h/yvc -c 7 dz/xompare the direction of the object's velocitx/ -ig4o+v cv7 yzd1;mfcr wh/y and acceleration vectors.

  When an object experiences uniform circular x:dq s0-hu2 bfmotion, the direction of the acceleratio:2dq0x fuhb-sn is

  Consider a particle moving with constant speed such that its ac49g+itt px,m xceleration of constant magnitude is x+,4ti9px gt malways perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in sk*4;ku m :f) q w:3,hyfbafuma circular path expka h:;* ) k:wmbyfusum3fq4,ferience?

  What force is needed to make an object msbpl:3hvt6gobj+s 1 3ove in a circle?

  When an object experiences uniform circular motioptx2j)s).2ahx.z (d.venjz g n, the direction of the net forcj ad (2e)hsn. ..pxv jzz2)xgte is

  A roller coaster car is on a track that forms a circular loop in thew.p:hasch1 goy,p-1i vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum valup1:ohi scga wh- y,p.1e for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a try1 rg8+)y6g .yazm wpeack that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, whg1e)r .myz +68gypwya at is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it3ckg5 1nvce6nb n lc)9 is going straight up. Jnln)6 k1b5 g 3nc9ccevust 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 radius /f*xx 3pwg f3 +7afevt$r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve / yl4ql/1:+szehmlxs a+ui3e 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 the curve for the second time, compareqls:m1e4//i+y ls+lz3 ueha xd to the first time?

  A car goes around a curve of radius r at a consta r qz8fp:.kf:9cxqt9 fnt speed v. Then it goes around a curve of radi ft.q :9:8zxqrck9fpfus 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 with (.8crr gj7vem dhn2*rspeed v. If the road is frictio.d8vg7 r*ceh2jrm ( nrnless 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 are bankz-qyvhy6 q1 u9w o)( xiljc0e-ed 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 radius ywhi-vuq690xy-le z )o1c(qj curve?

  The banking angle in a turn on the Olympic bt fj;kc ):2a0h-xu a6x(ezl jrobsled track is not constant, but increases upward from the horizontal. Coming around a turn,lt ;kae- uzac )(rx0 2jj6xh:f 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 2nibk,cz7 uhuau7qn 6z bo769circular path to have both centripeb 2 cuo7 67n6u79znku,zhbq aital and tangential acceleration?

  The gravitational force betw oof)5e9mbt mb8*v8rnyrc8 8jfjm ni4l h 6/q5een two objects is proportional to

  The gravitational force between two objz 6v5xl h-u58o6 euiznects is inversely proportional to

  Two objects attract each other gravitationally. xz 7 5elrpoy9/ e2k5yn87b6u3bg i kslIf the distance between their centers is cut in half, the gravitational force nl/p93z8y o7l5gsx 7 bk25rey6k uibe

  Two objects, with masas k9n. d (r79.dystonses $m_{1}$ 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 massenim0zesfyq6 ab cio:b l7(: 57s $m_{1}$ 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 grayv +*v9r,jmh sqdj3 b.+sn*j evitation.

  Compared to its mass on the Earth, the mass of anmhm:+ewq 7zjey*y/rteb- eid;+8 (y+ ugc *zb object on the Moon is

  The acceleration of gravity on the Moon is one-sfk g.m) 1nn, gj2y6uzkixth what it is on Earth. An object of massfu g2n,)kyk n 6zgmj.1
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 we8cgis*j +rudts9 j5 /light

  A spaceship is traveling to the Moon. A (j-el1z/7 nriv (sggrt what point is it beyond the pull of Eanzre gsr/ ((71jilgv- rth's gravity?

  Suppose a satellite wereqiuph*( .g)mdwg *z z2 orbiting the Earth just above the surface. What is its centripetal acceleratuqgz ig p*( ).h*dmwz2ion?

  A hypothetical planet has tmq-ra8 .1 bnq- kux7fa 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, t . aunk8q-m17-txrbfqhe acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what i:3 sor (vbzwqpq72/nlt is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon'z/lv2pr(bqwosq3 7n: s mass compared to the Earth's?

  Two planets have the same surface gravity, but pla9k ymrlq6u, eewi2 o24t9vl.rnet B has twice the radius of planet A. If planet A has mass m, what is the ma v9krl4r mwty,eli6o2 q .e9u2ss of planet B?

  Two planets have the same surface gravity, but planet Bd :5j2e4dvch t has twice the mass of planet A. If planet A has radius r, what isde42j tc: 5dvh the radius of planet B?

  Consider a small satellite moving in a circulcg/ztt3 *0qu2whm sr-ar orbit (radius r) about a spherical planet (mass M). Which expresstqc2 z-rs3 tu0 m*/whgion gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in tnh yze*idv)jcc3p;x 6 obnvi16r/4;ahe same orbit. Compare the two satellite's speedrynje 4) x;3;dib c iznpo a/16vhvc6*s.

  A person is standing +o *hk-w d+l iix2cv/yon a scale in an elevator accelerating downward. Compare the reading on the scale to the person's toih yk2ilcd*wx+- +v /rue weight.

  Who was the first person to realize that the planets move in elliwe,,zgq (x w5gptical paths around theeggx,5,w z qw( Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around the lbx. dywn r 9+f6,b7l8sf+svy Su9+lwnrys.6b vb +sffxd8y 7,ln,

  Let the average orbital radius of a planet be R. Let th.rqhr,q h g6y9e orbital period be T. What quantity is constant for all plar9yq6 g.h,qhr nets orbiting the Sun?

  A planet is discovered to orbit around a star in the gfm6jq otn 49*h.n;nznalaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the period of revolutionhnz;4m*j.nnfq o9 t 6n 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 "astronomicxtzwi1+8- l /ubzpli7al unit" (AU). An astlwpb-8l7/izti+zu x1 eroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.; ir6sz-tda; 03- etnxzj8;w1jsl a ak

  List the four fundamental forces in gl7:lo0vld 9( h-qirg fr-ak8nature.

  An object moves with a constant speed of 30 m/s on a circular trac)5 gq+y lg*ylva pcf6 27xag2mk of radius 150 m. Whaf pc56 a+xlvmgyl)a 7*g2y 2gqt is the acceleration of the object?

  The maximum speed around a level curv88l5 ihxr ja.te is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factor.85a8x it rljhs remain unchanged.)

  What is the centripetal acceleration of a poinooa7nf w53p1gi:s5p w t on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving gw13o7na ipf 5:w5pos 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is lo9eilzuw; s arwkd345(cated 0.200 m from the axis. What is the centripetal accelerati9uaew;irw34k(l dsz 5on?

  How many revolutions per minute must a cirfzz+h1)tolxp:*j x)2g io (jf cular, rotating space station of radius 1000 m rotate to produce an artificial gr2 hz(*fz1 :ftlpoxig ) j+oxj)avity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 1 cof9h c 1d ,1p-z3tjjsf.vcw250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcycle?s9 -,jtfoc1pcjhw1 f v13zc.d

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is a xike ,.k3cde3 cwz+6whirled 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 cewxd 33kc6ek z. i+a,if the string is not to break?

  A stone, of mass m, is att4.0r/xdancdc c 6p9xz ached to a strong string 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 stp0/c4cn9 dd6c a. xzxrone'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 i465: * oxemhc 9pjv 2se: r,dt5jxgzkcn a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's wei :5e:jjkc9ztsdx 56,h 4x2* rgm pevcoght. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences sr3 kff guw5xtu625b a462eddan acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the planedrgstuekxff 263w2a 5u6 bd54 is flying?

  A pilot makes an outsid0 xbmulm6*: td+ar5w se 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 +ldab 6x0srtwm * mu5:with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times hisas-a: :2ysoz 1t* pqsd weight. What is the minimum radius of curvature that a jet plane's pilot, pulling dap q -1s:*staos2:yzout of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal cur b(co:fbbmax(,(3 jm5q0s bgqve 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 bet(xb fj b3q0qb5(c(msa:go,bmween the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The c8f3,ku (hkb m)qll g1aentripetal fokq1l lfu,kh )mg3(8barce 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 ajna g3rwhdo i8(;lwk2)r,a4t t a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to makelh)aj it4;d8ok(rwg2w,3anr the turn?

  A car is moving with a constant speed v around a lva7edg dr2r1t6+ qws.evel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on thed6w ar+ s7.et q1v2rgd road?

  What minimum banking angle is required for an Olympic bobsled tw.l khvz/ f2)a2rc- seb 0z(xp kq8i6yo negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friction.)2 sf2-hzxb8v/l)a0kep .(wr ikq6yzc

  A horizontal curve on a qn+fgba-x 0b (b-jyc+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, banked at an angl0mr ze+f/pl *le of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked a)zl7ro1 m upd)j3z/ hbt $45^{\circ}$. 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 strin(:.l:f)r6 ryk2-mkeyp1 p fsx:y ancag is revolving uniformly in a horizontal circle of ra.:kp1f arks :)y:cye n(am 2lpyx -f6rdius 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 dj:y5xzi(nc7 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 z:5ncj(yd x i7numerical 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 conspzq2emm(xk h-g/)uk4;evd a 8ists of a proton 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 forc ,iw -/mdcg- )swjuk2pe on a 70-kg person standing on the Earth, due to the Moon? The mass of,-/cwkiug-) jmswdp 2 the Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attracti rp f+2my3v8cpve force between two masses is F. If the masses are moved to half of th3v pyf+2crp8 meir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from:5sl2mv iyo.-l ho1 4htta cr:z 1xf2p the Earth willmv21:x1lhoti5ry-lh4 c:t op .za2 sf the 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 i u;*jw xh6ia7+/yhz lqs $7.4 \times 10^{22} \; kg$ 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 dis;s6 fytpot.f*ui9 .gzpc d ),itance above the Earth equal to the radius of the Earth. What is her acceler z.ds,uc *6oti)gf tp yf;p9i.ation due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface wi5fyp pvmg g8 v9(ur8o+ll the acceleration ofpfy pr8og+g8vm9 u5( v gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal t-1znr/m7 xf xuo 3 times the radius /7 1rxfzxn m-uof 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 km from s r8ol5pd7 fqeoc98 e-wome planet's center, the acceleration of gravityqf -8cl 7rpeo8do5e9w 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 Eartp0pzad1* bg1 -q/ohwk44cw,z 9xs-nd 0v lugsh. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what i4w10xnd4*hso zls/pk9dzbp 0,-1cv ag uw -g qs its weight?

  By how many newtons does the weo3bk tqyu+ c:n+,j(w s-/b plwight of a 100-kg person change when he goes from sea level totnw:o(c qub+y,s klpwb/+-j3 an altitude 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 i:qb4sk; o6ep f6(ufuiw,3dt100 kg is at a point 3r above the Earth's df p3eu,4t(fob;q 66:siw ki usurface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and tw53a+ohx1no( n m6wamiice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how mu6i noh3n+ xo(ma1w5m ach would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, E 1b 1 r1xlk0yu e-kjyp *z)n1mpnaxd31arth, and Sun all lie on the same line, with the Earth between the Moon a p x-1xk 1n1y a30pjkld1mb)zey1 run*nd 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 k-kl t6g9lo ;ithe 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 cir(g:* j- pnmkfkrl)sq +z9vnrys 2 8f9qcular orbit about the Earth (i.e., it just skims the surface of the Earth). What nn*f+lj)f -(99 vs p2kq rs zr8q:gykmis 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 ++rsedg7a4s forbit about the Earth (i.e., it just skims the surface of the Earth). Hos4afs+7r eg +dw long 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 y a+j8s b3fbj:nz:8etorbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of t:bne3a z ty:f 8sjbj+8he Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbi)/nz-lo 0xp59tmi dmqwg*6i(m i a;eptal 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 zlomqj t +-ek-,gall 1pz* (r: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 jd0f5okcj+88 zkudiu 7q-bg42 ms .xucircular orbits. Moon A has orbital radius r, and moon B h 4-k7. dmz08jciqk 2x5jduu bs8of+ugas orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is,d 9ezuxvufq4u9 m9-a v(2 hn;a u (:ybft9ehn $7.78 \times 10^{11} \; m$ 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(se.kbwd f eu2z*4 xj 9-gcf8c orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth *(xjwu.zf cf42gcee b 8k-ds9to the Sun is $1.5 \times 10^{11} \; m$.)