Is it possible for an object moving with a constant spem/ onk*,5fl whed to accelerate? Explainmklh,w5 /of*n .

  Consider a particle moving with constant speed such that its6m s 0 zoe4ac(2k 2al8ibva/eq acceleration of constant magnitude is l2sek( m 2aioqe8/v 0aba46zc always perpendicular to its velocity.

  An object moves in a circular path at a constant-u1 y8e0wkxo - vf-voq speed. Compare the direction of the object's velocity and acexfk - -u1yo- 80ovvwqceleration vectors.

  When an object experiences uniform circular motion, the5ehf v-qbl)f5j f.ci2 direction of the accelere)ibh55vl2 f.j-q c ffation is

  Consider a particle moving with constant sp+b iwyjf(a-q9eed such that its acceleration of constant magnitude is always perpendicular to its velofa -(w+qyji 9bcity.

  What type of acceleration does an object moving with constant speed in a circpft ,a 0onb,eb072 wdjma gs6,ular pao p27ta0 , bdgf0jswb,,men a6th experience?

  What force is needed to make 8ev i8l.lbf 8gan object move in a circle?

  When an object experiences uniform circular motion, the direction oq l3ax:c zcby7*3sakmn; 3( ltf the net forceq tsz ;3mcaxlyabl33:7 k cn*( is

  A roller coaster car is on *rl v4dq8.eub* t,v l *i:lbnoa track that forms a circular loop in the vertical plane. If the car is to just mainto4*l*r vunqbt.bl, le:v *i8 dain 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 formor5omi): /gnfedc :2ud) (r 90rglzr os a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with u:g2( oddzerr r5mo)li 0 gcn):f9or/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-circular arc u h6sgxu *twkz).:rik +ntil it is going straight up. Just as the plane is at its lowest point, the force on him 6txk*wiuhz r.kg+: s) 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 curv z2z x7 q4 fqlvmufq3sin;913ve of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curi7g7f 2-sjl dlve 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 arou- gdsl7i2lj7f nd the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant u-nz3 iluvs:6f h,lj -gymo:, speed v. 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 seconduvlj-nuf: -hi oz, ,smy gl:36 curve, compared to the first?

  A car of mass m goes agcq 98 vtf c5 8vxi)pda.+q,qqround 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 force on the car from the9 q dqq8 cipa +tcvqx.v5g,8)f road is equal in magnitude to

  Two horizontal curves on a bobslp qr9*d- qdkr hc1zx.+ed run 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 smalle-xkzhqcdp*d.r 1 q+9rr 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 constan+doiz5(dz*u6h wf x. nt, 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 thn6d ohiw+xf(* udz .5zey do this?

  Is it possible for an object moving around a cirm7*(u+k)c7 vydcg 6ha(d4b,lwpr nujfo-6g mcular path to have both centripetal 7 (6(bd-m nf4+pm) cyg,crauhv6jkldg7 uow*and tangential acceleration?

  The gravitational force betxy-+kccn ;:jn ween two objects is proportional to

  The gravitational force betweenzw slu)58f y9 fk6kf(o two objects is inversely proportional to

  Two objects attract each other gravitationally. If kr/ bau3m(/i5ymg4h( gs q7fc the distance between their centers is cut in half, the ak hm4g7i u/bs 3c (yfgqmr(5/gravitational force

  Two objects, with massp2t :f70dbkxgpth*u qmgd4k . we*7n5es $m_{1}$ 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 massesiv p/xx:rws6y)r z 7j,v2,e bz $m_{1}$ 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 universal3z, hvq 1cx9vhllw60:(wv rat gravitation.

  Compared to its mass on the Earth, the masbrqx **qf9.3vq (f ylb6ts/c ds of an object on the Moon is

  The acceleration of gravity on 2 t*v-rgopy 2 c29iasqthe Moon is one-sixth what it is on Earth. An object of mas2-qc trgoi *2v92aypss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away f; 3 m48,6vltjktibtxorom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what5b )ci13n( 6qh *tcqtc,ohoyh point is it beyond the pull of Eat(*oth q ccn h53cb yq6h,1)iorth's gravity?

  Suppose a satellite were orbiting the Earth just above the se) -kkf :tsn.qurface. What is its centripetal acceleratit:e)qk.ns kf- on?

  A hypothetical planet has a mass of half that of t(y4n /*m s9fix;busxcic *p3phe Earth and a radius of twice that of the Earthyx* ;/upsf(4cn 9*3mbcp ixis. 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 gravity o:4n2 2ps +8hb;pnh aj2 o55ysoostcs nn 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 n8b2:a s o5+ntp4jos ych2s5shop n;2 mass compared to the Earth's?

  Two planets have the same surface gravity,d 5ni.)0o k f(rmny94znu :rdt but planet B has twice the radius of planet A. If plan o:m y95dnz.(0k )rrndutinf4et A has mass m, what is the mass of planet B?

  Two planets have the same surface grav; /x1emssfbzkt-vx/o r u.4*c ity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius cvk/o/ xrfs x-me1 4;u .*sztbof planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sp1jjx4,0jp vp(*azed fk2 7gfh herical planet (j 7(f j d 2j*vkphae,1g0fzxp4mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, a, w,jx. to7:fozjr6ignd rotates in the same orbit. Compare the two satellite's spee ,7jogrtox zf. 6ijw:,ds.

  A person is standing on a scale in an elevatozdk l-sj1;rkfg3c)0 a r accelerating downward. Compare the reading on the scale to za srkjd1kgl;0) -3cfthe person's true weight.

  Who was the first person to rea6xn bt-:j8v;afu nuk+ ys9i4rlize that the planets move in elliptical paths around the Sunkx49vu;n js:8+ fi6tynba-u r?

  The speed of Halley's Comet, wl2jo/g e pdy+w)qs 4n (5f3jqkhile traveling in its elliptical orbit around the Sunw2 5yqdsjf jge+l)3/ p4qnk(o,

  Let the average orbital radius of a planet be R. Let the orbi uk)z. -l 2v,oaum:tittal period be T. What quantity is constant for ai u.zukm, 2a )vtlo:-tll planets orbiting the Sun?

  A planet is discovered 2i: us g5 bb:oc8gwh8nto orbit around a star in the galaxy 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 revolution of thatun: i hg5o 8bwb8:cgs2 new planet be, compared to the Earth's orbital period?

  The average distance from the wavr.f48 per*yb vocv3)a; k+a y1ao+ Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the + +ac1 eakayv fb)r.r;*po8w4oayv3 vSun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.qn;0e6 d;yrekwt-zv /hd8;qndv2-v:/ dylb r

  List the four fundamentalrwc994ipsx6 kj+bg74qc. xe u forces in nature.

  An object moves with a cotd )v; pkda1z9nstant speed of 30 m/s on a circular track of radius 150 m. What is the aczv ta9dk;p) d1celeration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the ma,) snkf04jxhj:5a kdeximum speed around a curve with twice the radius? (Assume all other:) 40aj j5sfehd,n kxk factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle wt5yenf nj n h88ar989lheel of njt n9yfr5hea8 988nl diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 53 ss 8zqb::om i6kde2qdoyt5 ;c.cu 5n.00 rev/s is located 0.200 m from the axis. What is :iszstqd5 qde: 8m.co 6 ycu53knbo2;the centripetal acceleration?

  How many revolutions per minute must a cu m uv,/q sjb jqut7vr179w0c3ircular, rotating space station of radius 1000 m rotate to produce an artifb u vm j qc091/7wutrvsuqj73,icial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goe,9i v7mh d 5;oq h5df7qebivp/s around a 13.7 m radius turn at 96.5 km/h. Whafh9o /7dvqi b;d ,i 57q5mephvt is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is ,9nzz1q4 xyldibo)o:hd z7;v 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 to breakz );l1hx9b ,:no4yv qdzozd i7?

  A stone, of mass m, is attached to a strong string and whirled itr31/e nio+ecn a vertical circle of 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 rec/3ne 1iot+ is given by

  A stone, of mass m, is attached to a strong string and whirled in a7vx,l,i ,8 .o uh;ikfrklza:j vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times the stone's weilkhu,i l:f,i az;x.roj8,k 7vght. The stone's speed at this point is given by

  A jet plane flying 600 m/s e 7lt8 zwo3t.uwxperiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyil7 ut8 zw.t3wong?

  A pilot makes an outside vertiw/8ys8 j1smy+ )mwqgxcal 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 hiy x wmsws /qm)8j+yg81s normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven tiv x 8tpv o;ws5**z+vjhmes his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/ vx85+ pw j**vtsvh;zos?

  A car traveling 20 m/s rousr z-)b56k0 8(oel cut1lebej nds 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 l1)0lc8boz5juees bker( t6- tires and each road surface.)

  A car is negotiating a flat curve of radiusee,063 3sdpmidlcy 8y(t. st b 50 m with a speed of 20 m/s. The centripetal force pls3t8(spd i6d30bec.,ym yterovided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiusuqxg 1.1qea4ddwxev ;zm)*y2 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 thz;m12 v .qw*u4exgdx1y q)daee turn?

  A car is moving with a constant speed v around a le3 6se:o+l coqevel curve. The coefficient of friction between the tires 6qool s:ce+3eand 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 angle is required for an Olympic bobsled tpck,3m*xi( koo negotiate a 100-* oik,p(m3ck xm radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobs1 hia7d ez;vt d*qrx/2led 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 angler)bpqabu88i 6d2 ti5n of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankeb/uaf;6:gk)m k j8mqbe) /fop d 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 string is g c+durz9y3prn0ip- 8 revolving uniformly in a horizontal circle of radpz+p iu8r0- 3 9ngycdrius 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 areanxhjpv:6*m ; k, 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 i:6xvmjnk*h ;pn 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 con17t /fe*kltj qsists 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 th)x 8mz(do9nk ue Earth, due to the Moon? The mass of the(ko)dmn ux8z 9 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 masse/ ; nb 8rrmu3rsa3x8h7r)ddpws is F. If the masses are moved to half of their initial distance, what is the gravitational attractive ford;3w x)r anbd3m7rrrh8p /su8ce?

  For a spacecraft going from the Earth toward the Sun, at what distan 8o+3 f xdsxmpkx3,x, b5un1bqce from the Earth will the gravitational forces due to the Sun and the Earth cance+ qdub5kx3 fm x,xn3p ,8x1obsl?
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 Mooniz- vrf(24i zq is $7.4 \times 10^{22} \; kg$ 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 fwry .t ib(w0p8or a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration dub8(wwpr t i.y0e to gravity?

  The radius of the Earth is R. At what distancip+v3. shs*l bukf;)qiv u (9pe above the Earth's surface will the *p 3 )i ;lsu (vkvsq+uhip.f9bacceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its ibq5+(ceb 4t0i.ths tsurface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfa.het s t b(5iqb4ic+0tce of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of graviqv+qk 63q gye3wp )ae7ty iqea3w eypq 3k+6vqg7) 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. 7 0( r9zi2 mzrryxpr:h The Earth has radius r. If the object is raised to a height of 3r above the Earth'sx(097hrr 2py r imzr:z surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change whthm/zs(ws uf e;-di(qp- vw+)en he goes from sea lev fmt iuw; ps v(wqh-+-dsz/(e)el to 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 100 kn:y5s:zvq(7 m) 0q(k y q3sfukrrvtn*g is at a point 3r above the Ea m(35uzv(yq7rfsq :* )trq0: kkynvsn rth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the/lmzd hha9m 4-z2(roz Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the su9m (oaz2m-4ldhhr/z z rface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse,0k/ 7 hhtm9ptp the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and tht9hpp /07t mkhe 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 w-uiae )f;fv5the 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 lfa ci wp4 5ctoc578x3dow circular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speedxi7dfta cc8 4op wc553 of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit abo7ldbac)r:hz o/ gg c7*ut the Earth (i.e., it just skims the surface of the Earth).g :h )d*lcg7arzc /o7b How 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 orbit 230 km above the surface of t;jj3 -pkxyz cter8+9 vhe Earth. It is observed to have a period of 89 min. What is the mass ojj 8v- 9+3cpkxtzrye;f the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter o4p(yke; 9mm;jr o.ca ykmqjm2p1 ook, h7q8,of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon ofo 8iaa0t5j*bj:5y i sp 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 circular d,qmno0 me *7ge 03s4ae4btxtorbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon emtbt, me7anx30e4 o q0ds4g*B to complete an orbit?

  The planet Jupiter is 56n 4y7,x0bm1w,fhxhf zk lzh$7.78 \times 10^{11} \; m$ 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 thg,m+ej()8dgp1n vfy vrgux0)e average distance from Jupiter to the Sun? (The dx,gvm+v j)g8 ndf py(0r1) gueistance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)