Is it possible for an object moving with a constant su* pah-rm4 a/6r;mf kapeed to accelerate? Explainh/fukaapmmr- 64ar* ;.

  Consider a particle moving with constant speed such that its acce,9-sina lko k9bmy9h7 4i -xotleration of constah9lk4-a-ikoy97nbm ti9s,ox nt magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constagx*q1j:sxc 1 fen 5f; atwke(y;2fb9diyy8 l3nt speed. Compare the direction ofj82day15kw:fy1 9e (;eytxq cf3lsf*nxb;gi the object's velocity and acceleration vectors.

  When an object experi2p2g9u91t ft(lqevi rences uniform circular motion, the direction of the accelerr9 gq2e2vlf tt(p9 i1uation is

  Consider a particle m jjqj)x9 *4v.lt .xzumoving with constant speed such that its acceleration of constant magnitude is always perpendicular to its veloc .9xzxjmjltj*4q )uv.ity.

  What type of acceleration doe7hs0) abg 3vy6-glvjks an object moving with constant speed in a circular path experienceg7gl3-)jhk0b vvas 6 y?

  What force is needed to make an object move in a circ: hgk1 zxwxi 3 6(ox d,qvu.hi2gfc(2rle?

  When an object experiences uniform circular mott4 um7g ikc6*)ildkfu4 i*t x5ion, the direction of the net force4)f 6m*d4lcigi*x57ti utk uk is

  A roller coaster car is on a tracklzih(w0.y q3 a 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 minimumiq( 0lhzyw3 a. value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (ra:0m rs5dgzn 3(l k3o 0bfly0wcdius = r) in thel5n(3 wgfb y0 0: lcdzm0s3okr 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 at that point?

  A pilot executes a vertical dive then follows a semi-ciryz * 7nxg,b:ym/.farjcular arc until it is going s*ngj,yzafr7 .byx :m/ traight up. 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 rmz8dj.x9 pd -iadius $r$ 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 conh 7vki5w ,opeq x9v eiyyf0)9+stant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on tf wei0 vk5px9, oy 9vi7+h)qyehe car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a .q6/x h9;6mejij ol*wh i -rabconstant speed v. Then it goes around a curve 6qb 9*ijjilhwho xe arm/;.-6of radius 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 radi5tc3 uu)f4w) es5styu us r with speed v. If the road is frictionless due to ice, the car can still negotia5)t5wuc )s usut4yfe3te 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 bankemtth bo7)66 cz a:zqt3:+xk)3ytep ead at the same angle, but one has twice the radius of the other. The safe speed (no friction )e tp+ mc 3h6b6k3ta :ezy)qxot:z7 atneeded to stay on the run) for the smaller 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, but ihhm5*6dv+ y0 ikhebf* ncreases upward from the horizontal. Coming arih 0dbh hym6f+**kv5eound 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 object moving around a circuqrhb.*,l : g1:jsm 9,vxsiqpj mei 1(rlar path to have both centripetal and tangentia*:9qp,ix:i1lr .s1j ,sm q(mg rj bvehl acceleration?

  The gravitational fo6.mu05q i6q)ocwqns:2 yvwb prce between two objects is proportional to

  The gravitational force between two objects i qfxk v;l557fxjrax/:oa6f /o s inversely proportional to

  Two objects attract each other gravitationally. If tu(ou*3 ld;;tre:yi zm he distance between their centers is cut in half, the gravitational forure;ym i; z(o*l 3tud:ce

  Two objects, with masses xb.zjfhm* a y- ysd7)h5a)0uf $m_{1}$ 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 mabkzdj95k r) 4v; w4xlnsses $m_{1}$ 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 gravitationc7a 9h0l- 2g/5tp g3 jl nxrypyzpi*;a.

  Compared to its mass on the Eaxtq5lng4y++ bi 7o ad4pf7nb0rth, the mass of an object on the Moon is

  The acceleration of gravity5tyi14 njfh4ax4 oh3si ;5bok on the Moon is one-sixth what it is on Earth. An object o5ha tfio3 4y5k 1sox4j4;hi bnf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away v6gprve +;ej9r,hu8xfrom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the h(i;*w ncv. jzb(k 6u*dx x6ktrxo.2 lpull of Earth's gravity kxjbutrh.dn*v . x* l(x2i;6k6(wz oc?

  Suppose a satellite were orbiting the Earth just above the - dy8uhx+mlgf7 6xe 115wu )oedxlk4dsurface. What is its centripetal acceler+xh1d e61x udkuf mw gy4-5)7l8xeod lation?

  A hypothetical planet has a mass of half that of (rl*p8liwv/ wthe Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, rp8i* lww/vl( the acceleration due to gravity at the Earth?

  The acceleration of gravity on t)mu97( s lqko e23qlpbylf0v6 he Moon is one-sixth what it is on Earth. The radius of the Moon ipl7(l29ekfqqo0 v3b l ) u6ysms 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 planet B has twice the radius o)6n )etgwgt 3if planet A. If planet A has mass m, what ig3iw)tg ) 6ents the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice th moy)4yr o3h3h:0);l kzqbj mue mass of planet A. If pk qhmo3)olbmy4 3j ) z:0hyr;ulanet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) av, 915l ekzcyc:.b *4msnd pkfbout a spherical planet (mass M). Which expression gives this satellite's orbital velocity?ckpc9 5:4ndk,es.v1 ylb z*mf

  Satellite A has twice the mass of satellitpk( ; xdgq8q 3ekbph1/e B, and rotates in the same orbit. Compare the two satellie( q b1k /pk3q;xpd8hgte's speeds.

  A person is standing on a scale in an elevator accelera-* *ava6(p mre3ppbyk t5sq8v ting downward. Compare the reading on the scale to the pee a6mvv*8 -ay3p k*spqr (5pbtrson's true weight.

  Who was the first person to realize that the planets move v 7 ) (zaq .jvm5f5s4e)f albqtx2ibx7in elliptical paths around the Sun x7qlbzxtqavf5j7bm ).f ( e)2sia4 v5?

  The speed of Halley's Comet, whileg- 5/vaw;ylzi traveling in its elliptical orbit around the Sun,/lw vzy;-gi5a

  Let the average orbital radius of a plhmtnn/c.)2r zx6ztf8 anet be R. Let the orbital period be T. What quantity)mfn8z2t 6r z /thcnx. is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the gala(bg q (7cny7- .gsz67ylucsudxy 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 thacbugy7u.n7d-6 (lygq7csz s ( t new planet be, compared to the Earth's orbital period?

  The average distance from the Earth 3am: yi2 tkxy9to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid'y mt9y2:k3axis average distance from the Sun?

State Kepler's laws.,b to;( 7x:tbdo0hrt37jjcbv

  List the four fundamental forces44 .jgqt2kp i4dyng, l in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radius 1hr ee73u0yxr0z,c bc*en9 hd1+ ee(pa 50 m. What is the eexc3cehrpz(*a r 0e,+un9710 d ybehacceleration of the object?

  The maximum speed around a le7gcz0k.(blikqbb78az .o. b rx3bo5 v rj o,-evel curve is 30.0 km/h. What is the maximum speed around a curve with twice the racqvboj7i.8bk- e5a zlkb ,gbrb.z73. r( 0xoodius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicyc*tcp-+ d si-ryle wheel of diameter 70 cm when thedty*c-- rpis+ bike is moving 8.0 m/s?

  A point on a wheel ro mc;u(oy+kje:i::cqnn is.a; tating at 5.00 rev/s is located 0.200 m from the axis. What is the :ycm:;.nqinejsac(+ ; k ou:icentripetal acceleration?

  How many revolutions per minute must a circular, rotatin* bminw -9s*lsg space station of radius 1000 m rotswlm n-s*bi* 9ate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a md nxi8 /6uyt7e okf9:wass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force6 :of8y tnei u/7xwd9k on the motorcycle?

  A 0.50-kg mass is attached to the:x 8(c v+ kv(djmm/mix end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string mdm c8 j:mkv(v/xx i(+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 to a strong stvf*nv3-kfa4j-bj9e ao jx:bt0qh e*-ring and whirled in a vertical circle of radius r. At the exact topjb:j h--tk0be3 f4n9vex*a -oq*jfva 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 stone, of mass m, is attached to a strong st(bb9 -v j.3fdwal.uigring and whirled in a vertical circ3vugw.dfa bb i-9(.l jle of radius 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 ac9pvcq/ pk /r5nqq*2ji -vq 4igva0w(eceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane 9eg(* 2iqqrqk iwv0vp54jn q a-p// cvis flying?

  A pilot makes an outside verticmv t 3p5;al(mg+m8iclal 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. How fast is he5mpm +(v ;l3gicm8 alt going?

  The maximum force a pilot can stand is about seven times his weight. Whay49 koa ru77h82ut fqxt is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at 72k8x4uu 7haorfqy9t a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with )mammbj tj*q ;x(;/y lthe tires on the verge of slipping. How fast can this car round a second curve of radiua*ljm)mjbqmy; /( xt ;s 320 m? (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 spksg:gd nxs oll,4 4f;uv w0(a9eed of 20 m/s. The centripetal force providedlss;n 0gxlfu,k( :4w v4d9oga 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 spdszd ;ckqmt12 -l6-ckeed of 14 m/s. What must be t-dcc2s1kdk6q ;zm -t lhe minimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a /hs(5l - ,q1vapqdv)b +t8 ntjyzftv( constant speed v around a level 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 onsqz(jv5( l+y8vf d1t p/,)n ba h-tqtv the road?

  What minimum banking angle is reqiny 1l9dxe wa5:jg kur-+j(24w dh zx4uired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore 4n95r2ueh d- gla1wxy w z:j(dji+ 4xkfriction.)

  A horizontal curve on a bobsled run is bankecm*7(tf; zgg+als,k k6m 4grk /xoer 4d 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 angle ofo2wp3oyud 7.xp dl u10 $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedgctv5 dmolx8v i (ya(52y+ 4rq 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 revolving u /na .-qib7ynlq, r84t0 ttupx xel3+xniformly in a horizontal circle of radius 0.5tyl 3nntpbi0x8 .t/a-7rx,4 +xe luqq00
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 raq :a* x7pq/vrcce 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 numerical value in the blaqqc*: 7/xrpvanks)
(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 pr4 w-xo*wlhz dd3x -9g-+wk wwps8(yoi oton 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 gravitationalj9tt(obe+k3qmo5c ;)s opv go15c2fl force on a 70-kg person standing on the Earth, due to tk5g 5o+l1cem3tov o(s9ob j;qp cft)2he 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 for89 b,;rbblzyvce between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attract;blvbbr zy89,ive force?

  For a spacecraft going from thec+;5 vyly(p ve Earth toward the Sun, at what distance from the Earth v+yyecl( ;p5v will 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 Moong8+ed r/*(lm5 an plrr 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 for a "space-walk" at a distance abj esue )20,kyfove the Earth equal to the e2 j uk0,)esyfradius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distancev,w2wh1.w zy d(dq i6z above the Earth's surface will the6wwwdh zd1vq .2(,yiz acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at ata f w yy1.zsojdm eb,c((33/c2eh2tz distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity zse1t(c33 2 o f(e.2 w,cdhyajtmyz/b of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some pldg.o* ke;l*tw6pl+ lm w9yu 2yanet's center, the acceleration of gravityml+ 6lpd*y.w* yte;og 2ul k9w 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 Earth. The Earth has radiuily6w. *oi uz3s r. If the object is raisei.u3izlo*y 6 wd to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1zbeg2;( 4am: xln*jxs00-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Eaxgzjnb(m esl4 ;2* x:arth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg cx. (ez1cdv;bbf- o 2nis at a point 3r above the Earth's sur;ec bzvnx.fo b dc21(-face. What is the satellite's weight?

  A spherically symmetr7fsvd j i7p9cdx:jl(8ic planet 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 wouxfj7icl9 p:s7j dv( 8dld it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all-s+/lhg )c rf bk*gcz+pxump 3br6 ) ,pnf*kx: lie on the same line, with the Earth between the Moon and the Sun. Thfk rucpcb x6 rz* pbn lhx3gk+sm*:+,/-fg) )pe 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 transported2d* dbr/p 65b5gyzgt d 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 justc7e8djarh8rw ) rg)4r 4m +glb skims the surface of the Earth). What is the speed of the sajm4g c8)b lawe)hrg4d78rr+ rtellite? (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 j- ftqw*60n16s 5krkhw 0m b9jck xv3ibust skims the surface of the Earth). How long does it take to make one revoc0m 6bwbkkq3i0kv5t-r whfs1nj9* 6 x lution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abovg0blbf r:*+ 1kbboxr4e the surface of the Earth. It is observed to have a period of 89 min. Wha xbb*k4 rrgbbl0o+1f:t 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 an orbital diametercm)an/e;iyxe7 p;va 14 bz vy8 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 orb5 1wb56rv brr-, etftpits 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 circul(7p:vm:o0 zp/ csmzwuar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete op c:m0z(vu:/zmsw7 opne orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is eqwukrbkgqfg p6f-*, z 18- flue;4c0$7.78 \times 10^{11} \; m$ 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 orbitg g*nfw- (hjk,h6.nx h the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to thh n6hgk*wnfxg-(h.j,e Sun is $1.5 \times 10^{11} \; m$.)