Is it possible for an object moving with a constant speed to acceh1* eavq+m2 5vq9 aqmqlerate? Explain e*1 mqqaqavvm h2q+95.

  Consider a particle moving with constant speed such that its accelerlp9(ze+wbma (ation of constal( 9za pbme+(wnt magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare etnn shm k936)zces;4:dmcosvt f;8:the direction of the object's velocity and accelerationec4 e6 of8ntm)vhs smc : 3;tzkd;9sn: vectors.

  When an object experiences ub68ijn dvry26 niform circular motion, the direction of the accelerationr 6bvnd28i y6j is

  Consider a particle moving with jav-c1-j pi9 tconstant speed such that its acceleration of constant mc- t1 j-paivj9agnitude is always perpendicular to its velocity.

  What type of acceleration does an* 6a5yjenmva3:v;ncq object moving with constant speed in a circular path expe naqc y35v6av;:*jnm erience?

  What force is needed to ma8goq er: y)xz) pym)-nke an object move in a circle?

  When an object experiences uniform circular motion, the d1v/edzhvf vma0 l: 3 cck./nh/irection of the net force isz3v1 0hch//mfca ve lv.k:d/n

  A roller coaster car is on a track that hy3 )1nlcxe mghy.lhya)4) .q forms a circular loop in the vertical plane. If the car is to just maintain contl))4 y)3yla y qn.xhehghmc.1 act 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 onw cm6c+dome(d) j9j8h a 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 tojccm6o) 8(9j+dmd e whp of the loop, what is the minimum value for its speed at that point?

  A pilot executes a verticss9swwk),0v, v (6miw6v4uuqtr j) aqal dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, thq tq9vs,)k ws0uu46v m arwi,)j w6vs(e 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 curvet xlhx xzov2bm5n+ *0x u2,ce7 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 speed v. Then it goes arounymp 1 5 a: k6;v gcgvd+.00hmjfkpjfy4d the same curve at half of the original speef ;j g0f jkpdg5pkc04y1m+yhv 6.a:vmd. What is the centripetal force on the 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 constant ss(sj roe +kvh2 .s;c(8ehqy8wpeed v. Then it goes around a curve of radius 2r at speed 2v.h eks .(vjrw(8s ;oye2qc+8 sh 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 radrn yn :-7fw)roius 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 the road isrwf)7: rn-yo n equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the sam 8,3jlwnwn2 dr-h6mv4ctdb u,(1n cl be 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 themcjblc,w-8n3blu h rd w62td,n(14 vn larger radius curve?

  The banking angle in a turn on the Olympic bobsled track il5/ 0m kpj:2ud(vi6fvq -rmmas not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lowerv62-vrdqf0(5mmu am/j lkpi: coming out of the turn. Why do they do this?

  Is it possible for an object moving around a clt3gjm k(ar/ ctjy, 6.; oyx1kircular path to have both centripetal and tangential accelerm,;g t3rky a/(klx6y 1jcto. jation?

  The gravitational force between two oqo,uqa2 k q;*ybjects is proportional to

  The gravitational force b ,iovs 5 9qwle4adfhp:09fqx05u:r ifetween two objects is inversely proportional to

  Two objects attract each other gravitatio44x 9x8 mdjx1cw6ig63h q mechnally. If the distance between their centers is cut iwh3 emhg69x644qmxd cix8 1c jn half, the gravitational force

  Two objects, with mas0xfvtf -q +6w5cq/u fkses $m_{1}$ 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*.k 4o 1huysja9v3la qoeci1- $m_{1}$ 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 grd;nage9y :t .vfcn /y(avitation.

  Compared to its mass ollwopdzd1*.:vc d6r afp4-f :n the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earthsyr6xbxnhb ;0b pi 1*(. An objexp;n1x h(6y* rbib0bs ct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from thy6khb l6p+fcul5 99p l/u sdz:e Earth's surface, the rocket's weight

  A spaceship is traveling to th* m+6znme ;elmc-hpjyo7, y+le Moon. At what point is it beyond the pull of Earth's gravitymhe6 + el ,o+*m;-7zypmjlc yn?

  Suppose a satellite were orbiting the Earth just above the 72cykq *vq0 njsurface. What is its centripetal cq 0y knj*v2q7acceleration?

  A hypothetical planet has a mass of half that of the Earth and a m9t x-* pxj7heradius of twice that of the Earth. What is thep*xt j 7xm-9he acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is ofw02cl4y)na rn Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass c4ln wa2c)fyr0ompared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice 0tartdi 5;8lwbi+ gu+dtut67 the radius of planet A. If plat ltwi uad58+67di0utr;tg b +net A has mass m, what is the mass of planet B?

  Two planets have the same sur0a j,jreq n6t9face gravity, but planet B has twice the mass of planea ejtrj0nq, 69t A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving iu-p; n)k0 idean a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellitnk 0a;) idpue-e's orbital velocity?

  Satellite A has twice the mass of satellite B,wem;78 l:qxx c and rotates in the same orbit. Compare the two satellite's speel wq:;xm 8ec7xds.

  A person is standing on a scale in an elevator accelerating downward. Compare /p.ftw r1(py hx3jvn 1the reading on the scale to tt 1j wxpryvh (fn1.3/phe person's true weight.

  Who was the first person to realize that the planets move in elliptical paths ar9e rogqt)) fv.ounqv)re.f9 g to)d the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit aro+ v6;yiugdv)uund the Sun,vv6y u)d+i u;g

  Let the average orbita u 0cg gdw8ipq2oc;(4il radius of a planet be R. Let the orbital period be T. What quantity is constant for all planetsg(d;cuwo i 8g402qipc orbiting the Sun?

  A planet is discovered to orbit arounc85 ck94 z j-ohep,edxd 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 that newpx5c9k z hd8-4je,eoc planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the9 )nu8w-.cy)t+6euqhsr;j j sa z/jwh Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asncw8 j/+;a wu . j)tjzqhsu)y9e6h-rsteroid's average distance from the Sun?

State Kepler's laws.,xuj07b d. xlnz;uab.

  List the four fundamental ghr;niq s17 vj4ecp;w l is5/w49bu r4forces in nature.

  An object moves with zq,5tbasw 6 m0+c,wfe(v v8pta constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the objc a (m0v+vttb,pzwqse6 w58,fect?

  The maximum speed around a level rm1vp 0jyltdrdfe .d /3o/ag d+8q3g2curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all emddljod3 /. 0tyfp 1a3rg+2 v8d/grq other factors remain unchanged.)

  What is the centripetal acceleration of h fry11;nvit 8mi.i o5a point on the perimeter of a bicycle wheel of diameter . nm;f8tiri ho15i y1v70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locatm;9 0faj nwba6r h,s5eed 0.200 m from the axis. What is the centripetal accelerat6;a 0jn e ,h9sf5abrmwion?

  How many revolutions per n;mm s+13cht yminute must a circular, rotating space station of radius 1000 m rotate to produce an artificial gravic 3t+hmnmy;s1ty of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius tn1a5 i3p0l ncjl,y0jj urn at 96.5 km/h. What is the centripen5p, lnjcly a0j3 1ji0tal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a ,+snru g/t 2:qy, xlcg1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is thg +tsg2x,y q,c/l nu:re 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 vertic sp1 ,f,x f/ )joyfwdvjrze1.+yu5t- hal circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. Thv 5+ fypz x1wjo-r/,)e1f,s tujf.d hye stone's speed at this point is given by

  A stone, of mass m, is attached to a strong strinb d9-(e3cde :rpluw0ag 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 st0db9e u( lc:perdaw 3-one's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acgv o 6s95wkf0cceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is kgs6 95c0w fvoflying?

  A pilot makes an outs)6 wzb-ftv7 :jxfwn. 6a gbefpj0 ww04ide vertical loop (in which the center of the loop is beneath him) of radius 3200 m. At thegff0ve)aw:06 n74-z w xww.ftbjjp6b top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can vfu7*kf )l3bu zmv+*estand is about seven times 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 omzf )fu3+veu* b*k7vlf 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires on9u9kb9af5d ai)w;kp q 34qsvn bp;-sv 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'sauqb 5ak9vfws; p) ;kd9-4nsiq bvp93 tires and each road surface.)

  A car is negotiating a flat curve onu)ktt ym:0e,u lc q.-f radius 50 m with a speed of 20 m/s. The centripetal force provid qtc klm0.yt)u,enu- :ed by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curm.e 1st;nt.ann n8d;gve of radius 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 turds;nt..8a t;gnmn n1en?

  A car is moving with a constant speed v around a level cun( w2 ry5ihd0p1dr qw9rve. The coefficient of friction between the tires an p yw(w0n9 id12d5rrhqd 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 requibxp .6 hp(ekz2red for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding(xp.e pk b6zh2? (Ignore friction.)

  A horizontal curve on ad+ 6boxv1mx;a8) q tjk 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/l eox* dpl) 6xseej,+ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankecfqy ddwz f0.3es:)k ,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 va31mp * tjj3; vc94 4e/dgpl 8hzanxfrevolving uniformly in a horizontal circle of radius 0.500* jh4jdza19p lpf 3g;mn8 xc /avtv34e
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 uniform s,8rcej );v,5bkbn8jw+ae gf c; d:)di+ khcyrate to a speed of 45 m/s in 15 s, moving on a circular track of radiub)g :8y c )+dh5 waijc8k,;, fj+ n;bksvceerds 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 consiyz oq;1 hjwp- u60s g-y m7:mji2nzv9hsts 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 ajfwd0s-p ouk3dn 9n7j7xy56j 70-kg person standing on the Earth, due to the Moon? The mass of the Mo37ws j7nxjon p9j-6yfk5du d0on 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 tww3z,*t1yuzcl 3bz0g g +wa0mi o masses is F. If the masses are moved to half of thz 01t,0uc zimyglgww3*+ 3bzaeir initial distance, what is the gravitational attractive force?

  For a spacecraft going fopb,6 73 ep5 bqulh0jprom the Earth toward the Sun, at what distance from the Earth will the gravitational forc bh0elpqopj 5,3 pb6u7es 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 sr3w*w n6is:bzw(pm 2is $7.4 \times 10^{22} \; kg$ 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 above the Earth equal tos -i :gjj :cs-f+as(yn the radius of the Earth. What is her acceleratnic:jsgjs + y- a(sf:-ion due to gravity?

  The radius of the Earth is R. At what distance above the 90vv8b8u- ckagv(j np4y q/teEarth's surface will the g8 v/b8ka0nvu (cvjet y4q-9pacceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abov+2 gafrw( (xz /vx*mrre 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(mv*xw+agrr( x/r2zf the surface of Mars, is

  At a distance of 14000 km qiv3-gp 6/p pfh ikqjslim kb3-9 m8+3from some planet's center, the acceleration of gravity isj-s kvmp3pfqilg/- mi3p kb3+qih8 6 9 $32 \; m/s^2$. 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/a sl dh,. *kwu8,xrht4gsue0yx2r/x has radius r. If the object is raised to a height of 3r above the Earth's surface, wx,t/hau/uxre8k*4r yhx.d ss2 w 0g, lhat is its weight?

  By how many newtons does the weight of a 100-kg person change when he 9aht( p7a6* iitbu;m ygoes from sea level to an altitude of 5000a(i76puabyt*9hm ; t i m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at ajwxhdf 9eo93 xr2;g 7rgw+j2+q a8fii point 3r above the Earth's surface. What is the satellite's ri xiexhoj wd;22qragw79 +8fgf9j3+ weight?

  A spherically symmetric planet has f w90pmuk;d9ier i.(pjour 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 would it weigh on the suri;u9i0pd w( 9 kmjp.erface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, with quw,rq: fm;be;i5wt ) the Emtbu i; wer)w :q,5;qfarth 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 tzwvx:y ,.h*nq-m oma d+j 3/vtq5u m+wransported 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 sk((,znrt+ oe:laebh- p ims the surface of the Earth). What is the speed of e+(tbl:hp,ean-oz r ( the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit abjr0 30h /i/0r a,sabrmchj 3sqout the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the rb qjrh, 3ihms 0jsc30 a//ar0Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surf *5zrxj. qwutflk,v e 11 zwo3)gb0bw4ace of the Earth. It is observed to kb.wv 5bt0r4g 1zf1oe3ljq)* wzwux, 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 Jupitep*t *r(4g eh(e 9vtt30wnz ..aagys 9 acsfxm3r, 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 planet with a*mh mjvqgb(iqokc*(g0h n.17 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 nearl- lu4q1rvetwug (q 48by circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to compu8(g-qw4 b1u4qvl er tlete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter il70 zlto rl3+q s,+q.(xiwxrbs $7.78 \times 10^{11} \; m$ 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 ise7f6kl2 lzx8a3has. e the average distance from Jupiter to the Sun? (The distfk.aela z6ex 732l8hs ance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)