Is it possible for an object moving with a constant speed to accrmezs0o7t xb . mqs).h/4z0ljelerate? Explain0qx z7l)th.bo.zmmjsr0e / s 4.

  Consider a particle moving with constant speed such that its acceleration of ea1 0rvta8nk4 constant magnitude is always perpendicular to its velo4k1e0rt8 avn acity.

  An object moves in a circular path at a constant speed. Comparsj 0,w(anxp7l4 i p/upe the direction of the object0(7/in 4p p lxju,wsap's velocity and acceleration vectors.

  When an object experiences wk86 3pl,b 0isi oic6zuniform circular motion, the direction of the accelerati0i 6k ,ip3w6 csl8ozbion is

  Consider a particle moving with constant speed such that its acceleratio k4al kgkg9i c:-8sy5tn of constant magnitude is always perpendicular to its velocity.4 c5a9lkkt- 8g syi:kg

  What type of acceleration does an object moving t+5n)9ps24yhlht l ;gpi tx3awith constant speed in a circular path ex p n3 +ty2xi54spal;h9lt)ht gperience?

  What force is needed to make an object move in a 5 dnv,;o1cukdsm28ft circle?

  When an object experiences uniform circular motixfl;yh:jz 2a r;o99eson, the direction of the net force izxy ;sh9;9 2al oefr:js

  A roller coaster car is on a track that forms a circular loop in the ve;6)zk8 o3hjfe em e(jurtical plane. eekf ;6(j8)o3j hm uezIf 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 point?

  A roller coaster car (mass = M) is on anarr52gg yg-wn7 zx5/(hrn y- track 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, what is the minimum value for its speed az ggxy(ayg/5-r 2nn- wnrrh57t that point?

  A pilot executes a vertical dive then follq xmpu 25tm442,b z6eatt;*g 7ushfs mows a semi-circular arc until it is going straight up. Just as the plast htz;2mmup, 75uqg f aes46m4*2txbne 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 c * de5aj)f:euiurve 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 speseof025m8 :4iu akzj h ap+x4ked 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:ama hi+0 4k zj oux84p5efk2s the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed ; he;+bdt2fwz a1msi) v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes;ethid1 zm) 2f bwa;+s around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. 7q v))o1(ba9i. xxtu bqk g3umIf the road is frictionless duq u 9vt7gmuao(3))bxbxi.k1qe 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 banked at the same angl hsdjlk : lp:r8r*446zi4wnz ae, 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. Whath k:r*jr s:z4ipa6zw48n ld4l is the safe speed on the larger radius curve?

  The banking angle in o o q. jzvoxs30cy3i4*a turn on the Olympic bobsled track is not constant, but increases upq vc o* y4si3xoo3j0.zward 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 they do this?

  Is it possible for an objec+8/psv;5 gnmlns g/m0 d,ebaqd xrw69t moving around a circular path to have both centripetal andx,69bp ;8+d 0/gsgnvlesm a5/wrqm nd tangential acceleration?

  The gravitational force between two objects is propopxd .hfr+vv+.jg7m ygk;hh x/due6z3e( 3 hg0rtional to

  The gravitational force between two objects isu/158 xta gpvpw/k1jl inversely proportional to

  Two objects attract each other gravitationally. If the distanc/ t k)*j2c:l6 p6*dgda mwkslbe between their centers is cu dgsltk)*k/b jdaw 2lp6cm :6*t in half, the gravitational force

  Two objects, with massnz3htrz*9 syh/d v6i 1( 6uacmes $m_{1}$ 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 sopu7qww((mx i 4;il)$m_{1}$ 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 gravitaa 7k;.whx ,) hku im1f4nbp:phtion.

  Compared to its mass on the Earth, the mass of an90+spz 7 daily5od)ya8e; mpu object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on q x n j2f vs)8;k.ps zijshnzm-,58hg6Earth. An object ofx fngvsj-jkz,5m sh.qpni8 2 ;)8h6sz mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface,lt vsi6 uh)bm(q)j8khrwt/nw/ v)20v the rocket's weight

  A spaceship is traveling to the Moon. Atb 7kz0qnrlo jt2z),53t-keki9 :bx ve what point is it beyond the pull of Earth's 2o9kk37 qb,5 bi-0zkl zterxv:ntje) gravity?

  Suppose a satellite wefsh;x u(jcb y:0.tzn24 bc1g fre orbiting the Earth just above the surface. What is its centripetal acc2(tgn4ubhcf:f0 xb ;j sc1zy.eleration?

  A hypothetical planet has a mass of half that of the Earth an0uzq)z 8c6re crv4 ;csd a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of )s840zue6r zc qrvc;c g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on theo e zf8mb8.im: Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is thom :f8izb .me8e Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but plapp;ogpq/ ue;pek v*7c 0ft-b 9net B has twice the radius of planet A. /pp*; 09- 7ve pu;e fpqbocgtkIf planet A has mass m, what is the mass of planet B?

  Two planets have the s*)zzwq;vtn0 lw k+j5 bame surface gravity, but planet B has twice the mass of planet A. If planet A has ra nwqj;)*+z l bkwvt0z5dius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius rs)xml 9yf ogj9or,g4v:f.)xr ) about a spherical planet (mass M). Which expression gives this satellite's orbits fgr94 r))xxjf9., vmygloo: al velocity?

  Satellite A has twice the mass of satellite B, and rota1in2ho5u f h1ftes in the same orbit. Compare the two sateu h1 5fihfn2o1llite's speeds.

  A person is standing on a scalhyanv 9wj;fz 7b,j- a6e in an elevator accelerating downward. Compare the reading on nh,; bfj yavz6w9-j7 athe scale to the person's true weight.

  Who was the first person to realize that the planets move in elli ;/zkhd. rcdju37+ . vpstu05+bleomeptical paths around the Sm v/;+pd0e c.l. bz3tkodj5shu u7e+run?

  The speed of Halley's Comet, while traveling in ev(2: ylvg:y oh 1kk+sbm1r,gy.tfn5 its elliptical orbit around the Sklye2:1tyh( 5o1sgmrbv :f . vn ,gk+yun,

  Let the average orbital radius of a planet be R. Let the orbitg5b ww1xi k/z5al period be T. What quantity is constant for all planets orb/1z 5i5 kwwxgbiting the Sun?

  A planet is discovered to orbit around q 2au*x hb+ct(a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times tu+t x *b2ah(qche 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 tuc 7ftxd+r.5rax9q rn z;k4c7 8(blxj o the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a yeax .xu cqlbd5(c9a jknxr z7;+7tr8 4rfr. What is the asteroid's average distance from the Sun?

State Kepler's laws.rilhx*twk 8z5: 0c-n qqbuv kvn-8,l ex*3.zd

  List the four fundamental forces in nature.j 4q tb hkl539w(wmn*wiq) *m06yqvzt

  An object moves with a constant speed of 30 m/s odrh)2 b a,-oo(w(quzen a circular track of radius 150 m. What isharz,u dew -()ob (oq2 the acceleration of the object?

  The maximum speed around.(3;h x.ay c kjt/xqal a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other faklcta jx/3;a.q(yxh . ctors remain unchanged.)

  What is the centripetal acceleration of a po.ztbspbk qb5wqa1:o2vb 56 y 6int on the perimeter of a bicycle wheel of diameter 70 cm when bos5 qz1 v:5kbb2yqp6bwat 6.the bike is moving 8.0 m/s?

  A point on a wheel rotaulpc1ys sx3s w1c(fh(5o xcx1.kby .x *b9k0vting at 5.00 rev/s is located 0.200 m from the axis. What is the.x9xbc x 3w1kc*.kv5o1cyhxspsbl(y01 s (fu centripetal acceleration?

  How many revolutions per minute must a circular, rotating space60ix p *xkseo 5p*d9vm station of radius 1000 m rotate to produce an artificial gravityv6*i 9sdpp0 *oexx 5km of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It grm5m.h i69*j meo*nnyzi2 -pfoes around a 13.7 m radius turn at 96.5 km/h. What is the centripetz5oy i-*n fmmi*m 2e.nprhj96al force on the motorcycle?

  A 0.50-kg mass is attached to the end ofjgih7:.,pdyh a 1.0-m string. The system is whirled in a horizontal circular path. If theyhi:g j7dph ,. maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached tou g*-oz3a z;w h+ab+oc/ccva; a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tensia;3o; za chcza+u/bw*+ vog -con 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 attacs)2u,d70 s2ll6/h0 d gl1r1/e ew hss zkagvnlhed to a 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 st zs7 ssh0,ldnkrvs0d gl2h 612)/eu1g llawe/ one's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling(;za uh. kfq:-rz(y/p2crigu out of the dive. What is the radius of curvature of the loop in which the plane iz z.(khpugrcu f-y( a;q2/ri: s flying?

  A pilot makes an outside vertical loop (in which the center of th4qe6r1kuztx , 6t-pnr9lq9b pe 9jhk;e 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 his66b 1rp;kpqlzeh,-k 99qt 9xt j4 enru normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What is ot;;j6ewvx+, az enm ;the minimum radius of curvature that a jet plane's pilot, pulling o,e6+mwj;z;no va;xe tut of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radixgdm ,y74zukl:41so bng x,h4b 5goo+us horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assumkh 4ux,g4bgz7 bd+ynlo:1s,4 5 gmooxe the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a f:g)eu-bczdvx-3/ fx qlat curve of radius 50 m with a speed of 20 m/s. The centripetal force prov x- u3eg/-xq v:zf)dcbided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radings qx7vwu)e1t((d/ze ,g. c go:h.o rus 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the uq : ev1 ,7gw(ogg.o)rz / (sdxt.chenturn?

  A car is moving with a constant speed v around a level curve. The fkb2 :u14+nudpjf/ ql 2e z2tfcoefficient of friction between the tires and the road is 0.40. Whafq1fn2 2ul epu2z 4j/bd t:fk+t is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking an6vrjmdpd)( 0 fgle is required for an Olympic bobsled to negotiate a 100-m radius tdv0) f drmjp6(urn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bann5w * vmrdd4m9(uz)yd)zfol8 ked 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 rdm wq1+ ar :pc*r ld fv+5.x9)s3qxspmadius 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 am lm n3i;oxcw)d qq0:3b t10cat $45^{\circ}$. 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 dtmx b*x6(y )cend of a string is revolving uniformly in a horizontal circle of rad6ty x)(*cxbm dius 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 : drdgjoru5zx cq7f/ 0*ee)+luniform rate to a speed of 45 m/s in 15 s,*ez +05ucqo fx:d/d7 )ljerrg moving on a circular track of radius 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 pro 7id a(cti,w.aton 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 Eartgaq/ix f p3a)4h, due to tha)gf p/xa 3i4qe Moon? The 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 masses is F. If the masses are mie/zapa:h k.ukt- 5 l.oved tolehka5i:-tkp/au z.. half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towahn su6p36ik-hy sc5vc 3l0s bm)ve;a)rd the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cancel?c6hm bvc 03svkh-l3yn6)a5;)p ise su
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 isx ax9b,t zf.:h $7.4 \times 10^{22} \; kg$ 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 a7cie m94 jcy:xjdu /:j2:s lom msa n)(tk7ce0 "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her accelej0:)s x( l eu:9mcmisj ot2 d4jamk7 e:7yc/cnration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will3l4k:+4nck52 raebpj lwe 8qu the acuk4jaw 5 prc23l4ke q:8n+lbeceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distancez: ,,*rvbvrc i9z:va f above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the sate :crzv, ,a f9rv*:zivbllite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center,ofcnm+ 8x d+r;amo 0) sd+e,gf the acceleration of gravity isr0 )c8o ,+d+maf ne oxs;md+gf $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the s*r-c1 tm d8irsurface of the Earth. The Earth has radius r. If the object is rais-sr1rcd8* i mted to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the9b mq;z cfa* kf10gg9n weight of a 100-kg person change when he goes from sea level to bfgg af q01cnzm9k*;9an 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 10n,t 2j,z7(s bqz1v vmm22dqgd 0 kg is at a point 3r above the Earth's surface. What z,,1zsb7qqv 2m(nt2mjdvd g2 is the satellite's weight?

  A spherically symmetric planet has four times the Ej 2g evcd-56dtarth'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 this de2-vj5 ct6g dplanet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie oa 2c bgfok:pl 0(-q(rzn the same line, with the Earth between the Moon and the Sung2:o qlfc0 rbz(-a( kp. 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 transport kjgtthv7(m+0 ed to 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 Earth (i.e., it just skims(5f mvd) caf ,cr:6k7) hdyh*tz;s fqp the surface of the Earth). What is the speed of the sat th fpd5)6cks;h fv zry:c(*dmf,q)7aellite? (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., it just skimc4cs 2,p-ljj e;v, agd89aeaos the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Ea8 vj,s-d;g2p aea , cec9ojl4arth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above ,ig: h4 my25g9k dem,mbfnf,ba 2::bq: vcyngthe surface of the Earth. It is observed t2:vb,:mygcnb 9 gn::y2 qimfk,hdm5 ,eb4 a gfo 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, has av6itbg p,6x7 in 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 jw)6rj*vye q5g;9 ntrthe 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 imlgna,m ynf zawd.) ek)b141sqz1 j27 n nearly circular orbits. Moon A has orbital radius r, and moon B has orbital razfgmbd.nq7)emjal1 za ns 1w2) 4k1,ydius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is4w87 ff/zqae k1/z(. adxm yzq $7.78 \times 10^{11} \; m$ 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 h+dhfu1 l)sb+u; ovz7d4u3pb 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun isohp bf 3+u ld1 ;47dhvus)z+ub $1.5 \times 10^{11} \; m$.)