Is it possible for an object moving with a constant speed to ap :m .ldz*4 tgl+ov*mqccelerate? Explai+ol.* pmgl* v :dqmtz4n.

  Consider a particle moving with constant ro8z*w 8,a f4casnfv2 speed such that its acceleration of constant magnitude izo f *8af4,a cvs28nrws always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dire-o++ kck tyfon,; nig/ms.e-owsj3a7ction of the object's velocity and acc i, sj;+ to 7+/ynnk-c eosmfk-g.a3oweleration vectors.

  When an object experiences uniform circular motion, the direction ofsgvbj 8+k3 ;os the accelerationb38ks sj+ ;vgo is

  Consider a particle moving with constant speed such that its acr6ah/( qp8wt. hp8wbc celeration of constant magnitudeah(bp8tr hc8wq .w p/6 is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in yezc e:+h+:d(5glmysa circular path experienhy ++yzdmg: e: 5lecs(ce?

  What force is needed to make an object move in a cirwm/-7gs jd :jmcle?

  When an object experience j(9k dy57n-ak(malsq- puu6rs uniform circular motion, the direction of the net forlku--5(qja 7s9ukpn6( d mr ayce is

  A roller coaster car is on a track that forms a circular loop in the verti3ujc:w4 ks;xq cal plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this;u:q w4sxk3 cj point?

  A roller coaster car (mass = M) is on a track that forms a circular ltw*00jv 0,lp h0;zu peb jdtv8ldo1( qoop (radius = r) in the v vq*luj8; 1zdhw0oe0jtldb(pt0,pv 0ertical 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 at that point?

  A pilot executes a vertical dive then follows a semi-23qnhjpvwtb6r0r9mt t j+yz c)6:v z )circular arc until it is going straight up. Just as wy66:2z qttv0j)r +z cmbjh) 3pt9vr nthe 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 radiws avcw;z c;hatd*jz.2-y ol jkc40)5us $r$ 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 s2 btai8 bfesvd+a -9*fe+vvk;peed 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 9vtakffv be8a-;*e 2bd +ivs+curve for the second time, compared to the first time?

  A car goes around a 4w6brcvf wnk(mz3qo h*ucv:,-q *r p:curve of radius r at a constant speed v. Then it goes around a curve of radius : w6nqw,fkrz voqur *hpmvc*c 4b-:3(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 asfqpoc1 yg-/5 round a banked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal forcepg1c/so - fqy5 on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the sam 1eqlsse-lrj g, v7*g/m7ak *we angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smwe7qvj -7a ks gel* mrl,s*g/1aller 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 constant, bgwy4a+s u*d-5lk j-quut increases upward from the horizontal. Coming around a turn, the bobsled team will intend+aqug - y s4uk-wjl*5tionally "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 circular path to have both centripee3:gl8r 0o+fxd(prxxs4jzc 5tal and tangential accegdpsc8 e oxl4(30 rj:x5+x rfzleration?

  The gravitational force between two objects is proportirm1jp .wz*g 8lonal to

  The gravitational force betwep ; pbdztc*h87en two objects is inversely proportional to

  Two objects attract each other gravitation)-5qu s e0hl s+ukr7mb7*xyupally. If the distance between their centers is cut in half, the grpxu-k s 77 uy0l+5s)q bmeur*havitational force

  Two objects, with masses e;t*ar- qa;4-xe+x t*ahdu ge$m_{1}$ 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 ma f 1tsern7i4rtb); u9jzzh3y7sses $m_{1}$ 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 gra)p nsu4)txy47 :j7mpb- uzmq fvitation.

  Compared to its mass on sm2gy(qau v+nw g-hkf oi9m3 jv72j p5*i/)rathe Earth, the mass of an object on the Moon is

  The acceleration of gravity on thaz8yxg0cmh;gtk6 3: me Moon is one-sixth what it is on Earth. An object of mm;0ytmaxk :zgg6 38ch ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'. p di328pzgbqs surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyvjfz5azoq7v1 )/2wv+rwf vq 9ond the pull of Earth's 2 v5) f/vvzro q+zq v7wf19awjgravity?

  Suppose a satellite were orbiting the Earth just above the surface. 3g3;bn2q sxpnpc:kv/x 1/simWhat is its centripetal accelerat 3nckx /b2;x/n qvs1sg:3ppimion?

  A hypothetical planet has a mass of halsp0 godd w8n7n u.)qo9f that of the Earth and a radius of twice that of nq9 o )nguw0ds. 87opdthe Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gr uv adogyg2ba/55;9 cpavity on the Moon is one-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 toouay;d955bgga2pc / v the Earth's?

  Two planets have the same s5a ofuvh*oc0o+07 mwm4n6ct 9 wx- cgqurface gravity, but planet B has twice the radius of planet A. If planet A has mass m, whqo7w0 m9f gx acmcvut-*6c0 o45w+onhat is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of p,frqior cwp(/ jgh2g5f97y*elanet A. If planet A has radius r, what is the r ir 7,2o /p(gq*fcj5wyhfg9eradius of planet B?

  Consider a small satellite moving in a circular orb3 *0wxacoxbtila ;* -git (radius r) about a spherical planet (mass M). Which expresx 0olg *-a3a xbcwt;*ision gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and );zvl y5:fm( nvj-*rfaaw .phrotates in the same orbit. Compare the two satellite's s);m vl5 :a* jvf- pfnh(arz.wypeeds.

  A person is standing on a scale in an elevator accelerating downwaycg n nxpy2qi4vih1q 1a :6.s+rd. Compare the reading on the scale to the person's true weight42s qxg.6+c1 hv:nnypai i qy1.

  Who was the first person to realize that tap ( r:trnz7)gyz8qw;c0x(b 2 .eiat c*i f2athe planets move in elliptical paths around thex0icpag: b*.2ace yqt8ft( tzr2)7r(nw;ai z Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around tofvt3 g-2a a :wdjsf83he Sun,v j-ota 2swd8:a3fg3f

  Let the average orbital radius of a planet be R. Let the orbital peria y/ ;h-7wipivod be T. What;ywhaipv /i-7 quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galax4 cpv1d n:utsz) .mo,py Andromeda, with the same orbital diameter as the Earth around our Sun. If that pvd)zocn 4,m1:t s. upstar 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 sfb .wl*g -fxqchm+8-rkfa;4 is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's a rxs-w- ;4kl*8bmaf gf hc+fq.verage distance from the Sun?

State Kepler's laws.: ;ga 5fmvifsg p. 9gvts-cvq)58+fah

  List the four fundamental forces in naturemhrl.+a l* mi(.

  An object moves with a constant speedxva cz.o fu-/ brl38s/ of 30 m/s on a circular track of radius 150 m. What is the acceleration ou3.bflvoc 8s/r z-x/af the object?

  The maximum speed around a level curve is 30.0 km/h. What is tr* -zc9.ia vkshe maximum speed around a curve with twice thes.izrvc k-9 *a radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration4 1,f :kt0mmqf;g5gatmu 3c7e fxk2 wb of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is,0gk qg 1e :fmwmfbcu 4a3m57tt;2fkx moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the am 1ke u75x(p,w3ylg brxis. What is the centripetal acceleratior ebyl5mukxp713 ( ,gwn?

  How many revolutions per minute must a c wi9a) y.woz*tpygc x(57ldo5 ircular, rotating space station of radius 1000 m rotate to produce an artificial gravip(ot ya5l)*go9zwdcyw 57.i xty of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.u0ptvq :vl:ot c:a7;u 5 km/h. What is the centripetalp vtav o7qc;:u:0 ut:l force on the motorcycle?

  A 0.50-kg mass is atta9:fs9 , igdtxoched 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.t i,x:9so dgf9 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 in a vertical cirayzp 8*p;a z nqntu234cle of radius r. At the exact top of the pan8p 3upta2 z*ya;qzn4th 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 attac ip smv;e;*fm3hed to a strong string and whirled in a vertical circle of radi pe; mfs3im*v;us 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 ofora a(u t+ abn86h7rs- 4g when pulling out of the dive. What is the radius of curvature of the loophab8rro7uan-(st a +6 in which the plane is flying?

  A pilot makes an outside vertical loop (in wx(f.vwn 8mfhr2u pv 80naf;.shich 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 onl.nw2 x.a h fmf0 (8fusnvv8p;ry one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his w is.wqcf;m))*f4 xof ueight. What is the minimum radum)x *;s4f qcoi.wf)fius of curvature 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 horit ):s7qnd m4hwojr9x,5 sqga( rcmq(6zontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (mch((g5: q9),qadm6sq jo4rw 7r snxt Assume the same coefficient of friction between 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.n8 f9o/1wtphq The centripetal force provided by frt1p f9q /8nhowiction 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. Whaqxni bs g82zf o blq6)ueklzm7**-4l /t must be the minimum coefficient of friction between q 7flbisxe2lb84kzlmo n*q -/)u zg*6the tires and the road for the car to make the turn?

  A car is moving with a c/oy nvf0 qdmf5i.05ukl wc5x4 onstant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the mi5 cl fy nd05xu4fio qm.w50k/vnimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobdtc; p/gcn *5osled to negotiate a 100-mc5p/*ng doc;t radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve opylnl uzdt 8tb34 2+b lx;a0u+n a 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, ban eq2 ovcfev)f;mp4i1*ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked a3pkl h o nxd,1,g,53suubksw1 t $45^{\circ}$. 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 uniformlyfu9xsr2, 0q ln in a horizontal circle q0ru29fls,nxof 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, a race car accelera:o2d)xrw fz(t5eu w b*qbp7 k8tes 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 numerical value *5f u 82z(bdo 7eq x)tw:bprkwin 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 conskb.mp(ukj a5d jvw4((ists 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 force on a 70-kg person standing on the dqxd6n 98:mb vchjy7,Earth, due to the Moon? The 9q6bhmcj8 d n,d:xyv7mass 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 betwe*0 ye1uhkk53,tttwqbl i7x d )jk.g. fen two masses is F. If the masses are moved to half of their initial distance, whaqk5) k*j,tu0f1ky .ie7 lx .dgbtwth 3t is the gravitational attractive force?

  For a spacecraft going f;sa9 t;9oclrj2 )srk from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and tj;;kc)a9s 2l tso9frr he 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,l2srq ul lj(d.d,6 t8q8kdue $7.4 \times 10^{22} \; kg$ 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 aw v ce1.xv;laisabig,ac9/ce+ re0 i*7 .xrm+ distance above the Earth equal to the radius of the Earth. What is her ac*. v ce mae r i+a9v,rw.c0ilxacs+x7eb 1i/g;celeration due to gravity?

  The radius of the Earth is R. At what disprs,c7 ) p1uv0xjp9r51dgpnetance above the Earth's surface will the acceleration of gravity be cjp)7dp1 ,p 91ru5n0x rge svp$4.9 \; m/s^2$?

  A satellite encircles Mars at a di+ y k0gnop+ki;stance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface ofkyk+p+n0 og ;i Mars, is

  At a distance of 14000 km from some planet's center, the acceleration nal(6sm*ml m gwzpmj6o*17 7b of gravity isj76p*nw l a(bzm*m6om7gs m1 l $32 \; m/s^2$. 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 wn;k9(k a f9;kscmr /e*6fk duEarth has radius r. If km k fec;;u n/dr(ak*k9 sfw69the object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1fke:c. cl8hfuo 0qq sx55(1e f00-kg person change when he goes from sea level to an alt xl kee8 10.5ch s5qu:(fffoqcitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of masskuxp jw r zuq628*r95)raeodhlo+(j d 7i(a-x 100 kg is at a point 3r above the Earth's surrpqizu(j(o+uwo k2j957x8har a *6dle rx- )dface. What is the satellite's weight?

  A spherically symmetric planet ha6 r mwju-e(gh/10qj;sz tv 6hfs four times the Earth's mass and twice its radius. If a jar of peanut butter weiehj 0 1zgsvmj/uh t6q-6(rw; fghs 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 the same line, g8:2r,s6b nvu gwc q+;h 81nyalw2g vowith the Eartn6wggqarou;:v 12 sl82vgb cyh8+, n wh 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 to theo 61d i5jbkho; 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 Earth (i.e., it just skims.krlyh u0p7d .4cs ks3 the surface of the Earth). What is the speed of tdk3k4s l.pu y7c0.srh he satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Ea ge7t7m mog dgx25;a8vrth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution aroud85m tv;7o7me 2xagggnd 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.bgkts 7ivdm:jx9l) 6t22 jj-m It is observed to have a period of 89 min. Whag)2 62d7m:tjis vj-9m jxtblkt is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Juasj5dkbgg,3t+ /5t ci piter, 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 Jupiter orbits the plane,8n 2qg bbtt,b, ce 3oh-pzdz.sp b1;wt 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 radiusm7(ziq ) :13uoj4eqle,g x0g5gempff r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How 4j ffqq 3x5m ep eg:eu)zgl(ig, o0m17long does it take moon B to complete an orbit?

  The planet Jupiter is -qxktw+ x96zuo7 mo)l $7.78 \times 10^{11} \; m$ 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 * 6hs2+af 3yods di(azb8.q3 csfcn,aorbit the Sun once. What is the average distance from Jupiter to the Sun? fyi 3bcd (aa38,sah.nsc62fsd +qzo *(The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)