Is it possible for an object,lx8t wmr8xo( moving with a constant speed to accelerate? Explai rxt88xw,m(l on.

  Consider a particle moving with constenyg) , 7u6v:08bty*yzg) taszsxue6 ant speed such that its acceleration of constant magnitude is always perpendicu8yz* zut6: e)tsy)egsx0,g 6 y na7ubvlar to its velocity.

  An object moves in a circular path at a constant speed. Co83 **tb2c -v xr+poxh8+eosybn q2xfvmpare the direction o2 ntxs+2cqbpvexh 3y o8ofbv8-x** +rf the object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the directi.* 541lufc n7bp znvozon of the accelerationunb7l 5o.f* 4zcpvzn1 is

  Consider a particle moving with constant speed such that its accef n9 f* )(tdd6usy6 klxtd tyz,bjd-38;od.nsleration of constant magnitude is always perpendicular tdfns9j,tddtdu63(osnx8zf6d- lkt . yb y)* ;o its velocity.

  What type of acceleration does an object moving with constant speed ilslox*w94 a,z n hzd *r+pproow 9q762n a circular paolao rw4 d,prx9lzs7wh2+q*p*6 zo9n th experience?

  What force is needed to make an object move in atfp qgu5) a: d-8kjtdu6o e/ z)o*.dtv circle?

  When an object experiences uniform circular motion980 r bnj3oo*hbyazsf ,f-+j j, the direction of the net forc j a 0s9yoro3z8 +n,jjfhb-fb*e is

  A roller coaster car is on a trgert b*d, u+h9y.rd8,pdw* x aack that forms a circular loop in the vertical plane. If the car is to just maintarddbu, ,xgr t*hy.d p9 a*ew8+in contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster carfg*ly.g12kg x (mass = M) is on 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 top of the ly.gl* 2 1xkgfgoop, what is the minimum value for its speed at that point?

  A pilot executes a vertical d)ln b.+u ++b 0iisipfcb8:luv ive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him lf upb)0 b.:c8+i++inblu vsiis

  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 cryr*11 ys 38xcjj*venurve 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 cot** ) 7m (xb;7fohsoveot;swi .vc0vknstant 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 around the curve for the second time, compared bt*so;(hv)io m0 ;s cx7vv*o.f wekt7 to the first time?

  A car goes around a curvm/0 bck7wx0ntuwnngqn 2 bs8 s s2;o/5e of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. 5umnctb n7nkw8 q ;sbgs20n/w2os/x 0 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 arounee8exl1,ix- 27rh3x e ecx1sc d 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 the roade1 7-ei3xxc1 xe ec8 2xsr,hel is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one hasve-*fm t0c3hy twic tfvhc *0-eym3e 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 the larger radius curve?

  The banking angle in a turn on th x- xfp)cejnjjea)15;e Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wal))x;p nj1fc5j - xjeeal," then go lower coming out of the turn. Why do they do this?

  Is it possible for an objects/39xl 1u qubb moving around a circular path to have both centripetal and9 1sux qlu3bb/ tangential acceleration?

  The gravitational force between two objecs h0ou b8ln-j:r 5mx0ots is proportional to

  The gravitational forcu) + qjy*gn.ste between two objects is inversely proportional to

  Two objects attract each otherq9p4 aljxyl 7x1dw 6m;b+ rcf)hzk3u7 gravitationally. If the distance between their centers is cut in half, the gravitajcdm ;ul6 +7)qrakpx94lx7b hwzyf1 3tional force

  Two objects, with masszm i3x1d+p5hq es $m_{1}$ 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 masserhamgh+u: 68 ls $m_{1}$ 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 gravitv f68 (z0gi)ja*mkugm/g 8uqhation.

  Compared to its mass on the Earth, the mass of an objlloh: tu7s7u 3ect on the Moon is

  The acceleration of gravity on the Moon is one-si t r9d.hzrd;:cmfarx8*1 fq+fxth what it is on Earth. An obje q:ctra8f *.f;f r1rdm9hdx +zct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfav,t/z514d/jcmb* tvk(qr9e g c7nwf tce, the rocket's weight

  A spaceship is travelithki53yg l (x5ng to the Moon. At what point is it beyond the pull of Ear (53x hylitkg5th's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. What x( n.3q vg7vco *lts8iis its centripetal accelerat7 3n *(v.soiq 8lvtcxgion?

  A hypothetical planet .6)xo9wpkfk x;p os.xdd ea49has a mass of half that of the Earth and a radius of twice that of the Earth. What is tho d xx)kwd9s e9ap.f xk4;.po6e 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 on Earth )- zkq 8n +y6x4.kehg;ngyuyn. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass coy8k yk)g46e .;xnzygn +nq-uhmpared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radiu+ jbbr*k52ye ss of planet A. If planet A has ma*sb2y rk ej5b+ss m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B hasncxo8ar: mau ,t l1)l5zih1v7 twice the mass of planet A. If planet A has radia ,)n 7o1:xt1lhra8l5uvmczius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) ntgth;c* ;c 7gabout a spherical planet (mass M). Which expression gives this satel;cc;7nt h*tg glite's orbital velocity?

  Satellite A has twice the maud/ v280nlhv kmzx9g0ss of satellite B, and rotates in the same orbit. Compare the two satz00u8x9kn2g/lhv m dv ellite's speeds.

  A person is standing on a scale in an elevator accelerating downh n/,.(w:mydfami k5 eward. Compare the reading on the scale twe fiy km(:d.m/5h n,ao the person's true weight.

  Who was the first person to reazgmgo*g+z1 x2 lize that the planets move in elliptical paths around the Sun moz2gg *1zg+x?

  The speed of Halley's Comet, while traveling in its elliptical orbit around thz+gk5o/-osb mrh gkgxtx7: 9.e Sut 9 gk.sk/5+mxhr7zo gxg-b:o n,

  Let the average orbital radius of a planetn9or: dhw78fnhu* 1auodw 8 j5rs)sy* be R. Let the orbital period be T. What quantity is constant for all s *15n*8r fys)n9owwh87 d dhujauor :planets orbiting the Sun?

  A planet is discovered to orbit ary +x4t6wx7 f un,/-h wuhv5apq1rrvi) ound a star in the galaxy Andromeda, with the same orbital diameter as th+f v iavqh- u 7npwy6rw1uhxx5t ,4/r)e Earth around our Sun. If that star 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 Earthpe rc;9r6dwc3 4 lgsq6 to the Sun is defined as one "astronomical unit" (AUgd3964 wrscp ;q6rc le). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.qn /b4-1 s 9keog/ o+l(nqdjdb

  List the four fundamentsufavc80wn)*h6sos;9t w .o fal forces in nature.

  An object moves with a constant speed -r*; / qertu/xv3grpab9m z;h of 30 m/s on a circular track of radius 150 m. What is the acceleration oet9 b h //r;zax *-;3qgmrrupvf the object?

  The maximum speed around a level curve is 30.0 km/h. Wh:si httyey7/ k 098dmqm 2g0fyat is the maximum speed around a curve with twice the rk:0gf 8t sd20mq/ey7yym9i h tadius? (Assume all other factors remain unchanged.)

  What is the centripetal accelerati, qx4 e :tnlr;js+m4l 9ensbc1on of a point on the perimeter of a bicycle wheel of diameter 70 cm rxsn,n b ;ml41qt+l 4eesj:9cwhen the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m fr0q*(8 bcnkaliom the axis. What is the centripetal acceleabnlc ik*( 08qration?

  How many revolutions per minute must a c 9r2n(altrm2s)e qv 7xircular, rotating space station of radius 1000 m rotate to produce asx7m)9qv(2 lna rer2tn artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It gofy84iat 2nl8 qc.b t:0qqa(tn es around a 13.7 m radius turn at 96.5 km/h. What is the centripta. nt8nf0tqciaq 28:ybl 4 (qetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m sttj )okwci,ggf d0sdjn-p2 q32 b-8l/jring. The system is whirled in a horizontal circular path. If the maximum tension that the-,cfitdn/wq 0g3 dk-lsg)p j8j2obj2 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 to a strong stxbnc94(drriy59em 7i ring and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 timesi(deyci9rn 49 r7x mb5 the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, iss 35qdax) a6d.h9p3fgkmitq b.7g5sw attached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tensionqd. sw 6)g55p iqb.9 h kfa33sa7xtdgm 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 acceleratdkk z.m+lkz 91en/h2 j hvo6v2o lok,/ion of 4g when pulling out of the dive.dzv ok2,ok.ek n2 k1 ljov+h//zlh69m What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside veqmrn +ag(o, kl+ 5/8-ahxqqpyrtical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of ho+/ 5lxnqmqk-(qya 8ga,p + rhis 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 pilotv e rhp8i3+5sk can stand is about seven times his weight. What is the minimhi ve+8r5k s3pum radius 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 horizontan .tbhc, ocz5x, jfzmze :j-51)uep+d l curve with the tires on the verge of slipping. How fast ca,5-d)u,pct 1oczx:ejn 5+fzez b.j hm n this car round a second curve of radius 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 speed of 20 m/g:. oypz (8nu2a+fldg2qjosdo s;p+ . s. The centripetal force provided by fric2;p8+l(:dp nougyod fss.+a 2o. qzgjtion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat hpgupxlf f2s um6: d,(t4vm9, curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between m, ps:x,df69(t pgf u4u 2mlvhthe tires and the road for the car to make the turn?

  A car is moving withein+14x 3hg)ko(mg2e2 l v bsv a constant speed v around a level curve. The coefficient of friction between the tir(v)gie 321+lgvm nb ko4s2xhees and 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 req;i j.xdf 16q kwng2vc-uired for an Olympic bobsled to negotiate a 100-m radius tug;2w 1xcj i.qkd6nfv- rn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run7qg,m a-ec c7a 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, bankedft)lp aac5y( - at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80p+t: rcno5(jr zg+z-u m is banked 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 uniformly in 8k o,zg7ielk1xxhva3 q..m:y a horizontal circle of radius.e7 8:oy.k,givl 1 xkaxqmh z3 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 uniform rate -0 budxpxgtkeh8 /468lqyo1s to a speed of 45 m/s in 158pb6 e/ l4s0gxhudoxk1 y-8 qt s, 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 orti *z,(k uqu2f 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 Earth, de;gc 7d5x0mt+/ mi1n;y nvfsdue to the Moon? The mass of the Moon /t;md nx75fdv+ iy;enm1c0 sgis $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive foretr* oog*(c z1ce between two masses is F. If the masses are moved to half of their initial distance, g z*coeto(1 r*what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what disa/ fd(n+fpf1 fc u; 58xw4fcmftance from the Earth will the gravitational forces due to the Sun and the Eaa +ffm;dfu14c/ffc(wfnx58p rth 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 1xg5lb29gx vhthy p8 el60g;i $7.4 \times 10^{22} \; kg$ 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 equ4,nlz6qpk*,17tumzv jto442o w nkj o0u skt+al to the rat w4 4lj17qunztkotkukzms oop +,40* 2v jn,6dius of the Earth. What is her acceleration due to gravity?

  The radius of the Eardx/h dzdnh0h1a8 py /7th is R. At what distance above the Earth's surface will th 1hhhx /dpd0dzy7 n/8ae acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a de- qw6yucx,i5bb )eci98x, sy8m8fqd istance above its surface equal to 3 times the radiussq)x8cubi d ,- ,wyq8m68y9be5 eifx c of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some pw o2qlcy7w,e *lanet's center, the acceleration of gravity2wce lwoy,*7q 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 o b7byn7wen1 +;p4.jlf)r tyt jn the surface of the Earth. The Earth has radius r. If the n;)ywjnj7l+ 1eb7tft y rp.b4object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight;iuj b lsh5q)* of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earthj;qiu 5b *)slh is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above the Eaqvs5 wqn;0 m-rs 5;qnw-mr0q vrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mazf7lv(46p3 *epfc:is .kj ugl ss and twice its radius. If a jar of peanutkzi:l 7 3ffcse6vu. ( pg*4lpj butter weighs 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 el/iv 1 wqc li1juf2g idq*3//same line, with the Eardg cliljiwqeqfi/1* 3/ 2 uv/1th 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 transpnb o4j3te(3 av(v 8(p,nwfvjv4 e2umrid3 9eforted 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 tz:9sj,rb s dk(sn,j .khe Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth iss9 (j.,zjbns :dks,kr $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth o+z()* /xp/vuhgxuj uen- cxo au.3/d (i.e., it just skims the surface of the Earth). How long does it take to make(/p 3 oh /.xcgoa u) duu/*vx-zeuxnj+ 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 surfacujl*3vn.k zau 8+akv /e of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (Tv3uu ak*l z+jvnka.8/ he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has suf+x8+kd qcu-*f p ka8c t1+can 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 pgl 47+6/ -q sb/6naiosb vlywradius 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 ;rt2 b mb.e, fq/cbn;yradius r, and moon B has orbital radius 4r.bf2;byn;me q/,br .c t Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isi0lh9z yq/-u y4k* 5w kkp6gqp $7.78 \times 10^{11} \; m$ 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 on g/4-rw rnl4p0m,d,uzyodeu/ 4jz ;tnce. What is the average distance from Jupiter to the Sun?z// 4j t,wdumn4n-p,0u4yg ;rderloz (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)