Is it possible for an object moving with a constant speed to ac5 +d1gwigg q)zcelerate? Explainq+g g5zdi1) gw.

  Consider a particle mjv9hpp,ptua5x 76:dpvzf * q0oving with constant speed such that its acceleration of constantp06,tph d p qxafp*v97u:jz5v magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direc; po,d+um:j irxu7jb.*yg7v etion of the objec*,y i:mg vuxpjb77.e+ud r ;jot's velocity and acceleration vectors.

  When an object experiences uniform 8fm53gu aj.d scircular motion, the direction of the acceleration isua.dmf j8s g35

  Consider a particle moving with constant speed abmbukc*klc k.7/ i1 -such that its acceleration of coni 1*cua k.mbk/k7-lcbstant magnitude is always perpendicular to its velocity.

  What type of acceleratirmly8d i5fe*cwn1a r52 enfj 4z3 .9knon does an object moving with constant speed in a circular patj rn eynfz8 *1farw.l3e 4i2nm9k5 5dch experience?

  What force is needed to make an object move i-auc2 e3ao(4gr+ /rq rxg rga,n a circle?

  When an object experiences uniform circular motion, the direction of 74a; odvoz 29rhd( jbjthe net forc d;vjzd(7bro aj49 ho2e is

  A roller coaster car is on a track that forms auzr bq n:zu1cn0;5ihv2 ht;1h circular loop in the vertical plane. If the car is to just maintai:hnu1 hc0z 2 5u1hbrzq;n; vitn 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 tw pu9vfq.7v(.j ,ddffi y4er hb/y1 v.hat 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 at that f.hwvi(.j/y4 y79dbue fdpf .qrvv 1,point?

  A pilot executes a vertical dive then follows a semi-cir*.cltix7 fsn- 1z ztw0cular arc until it is gotz-lx0zs1cnw.7 ift*ing straight 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 rftgyyvj-//ie)y ,b v59n p q+wadius $r$ 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 aty- uv- i7elf t/z08lxq 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 fe-l7vi y0u8l/tq- x zaround the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v.wydkh5o h,4o0jt8 )az Then it goes around a curvo jy4ht,k5zaho 8)0wde of 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 radius r with speed.ub1go y3cd (s6mx6fy v. If the road is frictionless due to m 6ub(sy f1cod3.gx6yice, 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 o4t unxsi0 bg agj v/e,-;w6l,fn a bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (s-g6,bitne,4 gflux/ jw av0;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 the Olympic bobsled track is not constant, but inq2hv)9 h t9cd3vc n,jccreasenv9ct3 hdc j)2qv 9ch,s 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 they do this?

  Is it possible for an object moving around a circular path t4mfvenru8 0 0no have both centripetal and tangentia0fe 8mr4n un0vl acceleration?

  The gravitational force bq1,s0a 06iwk2emzoy42su js t etween two objects is proportional to

  The gravitational force between two objects is i kz.f8eqv1o. 1hlpo x y29ia/ynversely proportional to

  Two objects attract each other gravitationally. If the distance bj(m: a79m1* cv3gtf nfpyda7y etween their centers is cut 91:fac7dgmm fnjat7y* ( v3pyin half, the gravitational force

  Two objects, with matpd2mp07ma8 ts4 chl2sses $m_{1}$ 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 massph/ lml kh0-7duv(t 9mes $m_{1}$ 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 gravitationj(gkg5 eo3,gp:jpx 49rn8o nntlrg1 0.

  Compared to its mass on thmypjwu+x d .bh- m18u z57 2i4la2blwee Earth, the mass of an object on the Moon is

  The acceleration of gravity on uqj/ c:x* q)wuj z2g;dthe Moon is one-sixth what it is on Earth. An object of w ;ud:jcqzg*)q2 u/jxmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's +re,tc. ixk7/vfr;zy weight

  A spaceship is traveling to the Moon. At what po(e)fdj .0pw +oubke r)int is it beyond the pull of Earth's graviropwde 0u) (.kj)e+fb ty?

  Suppose a satellite were orbiting the Earth o a+kk,iu. r()eha xq sm)3q3wjust above the surface. What is its centripetal aqmx) 3ek.3sokh+rw) qa( u,iacceleration?

  A hypothetical planetwyqp-.+qrxb4v15zq w has a mass of half that of the Earth and a radius of twice that of the Earthbp5v4wqz y1 wxq-qr.+. 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 on the Moon is one-sixth what it is on Earth. The reos; qim px4q9c6w )ra-yt c2rb34a.g adius of the Moon is one-fourth tha)i-b3or; pyccwr.x mq 44g2sa9 6etqa t of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planebkh/5xmxa+w( irwr.v i k0q 3/t B has twice the radius of planet A. If planet A has mass m, wi/+ v3(a x.kmkqr xb0irw hw/5hat is the mass of planet B?

  Two planets have the same surface gravity, but pa(2czj qwr9p; lanet B has twice the mass of planet A. If planet A has radius r, what is thpqz2c w(r a;j9e radius of planet B?

  Consider a small satellite movi9xa1+ni tdwxbn9we8 *ng in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital +btx*81nnd9 a xwwei9velocity?

  Satellite A has twice the mass of satellite B, and rot09il t)6 /t7cwpbefz pates in the same orbit. Compare the two satellite'7bte 6lp i0)ptzcwf/ 9s speeds.

  A person is standing on a scale in an elevator accelerating c5 jfv3qg(a8l downward. Compare the reading on the scale to the person's true weight.ga5l fj3v(q c8

  Who was the first person to realize that the planets move k9a4evsfvvyf1 q;bb; 3q3-o p in elliptical paths around t 4q-bsep1 9f;3kov3y;qbvv fahe Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit aroui)yztlg)6in1/0 to a tnd the Syaii)6z /)l1tg o 0nttun,

  Let the average orbital radius of a planet be R. Let the orbital perio hjj*hw7l8 h5v *hg*n p15dfpqd be T. p5 jhh 7 lf 1hphn8vdg*wq**5jWhat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a 4+u o( 4zcvk5zl,y wokstar 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 okvkulwz5co 4+,4y(zSun, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomica y( o0es+tp8/qoid) ors-,ol 7ezlv 6z5w9rfkl unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the a+s0ledo7o/qr,zo 8w srz-ot6(l5i f 9evk p)ysteroid's average distance from the Sun?

State Kepler's laws.ygm6g m2shb-6+:ax9 rqyy1zy8os;bq

  List the four fundamendhv qd9e+jq+3 ovez+4 tal forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiu )nr0oavp3k: os 150 m. What0rpo )a nkov3: is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Wnw.pz 8ls91 m h;yw7bohat is the maximum speed around a curveyl19o78; nwhw m .sbzp with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bic tw3::*qqw-qtnu xfbu 9y02 uvycle wheel of diameter 70 cm when the y-x0 qn3 bf92vw::qtwuutu *qbike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is loc*+ g-t7b f e54v3gwzufwcx7cwated 0.200 m from the axis. What is the centripetal accelera-*5 gb vxt 7+fecu37wfcgz4wwtion?

  How many revolutions per minute must74vnjg) axoskbcmp rh1*1 jgv 4+2z3 j a circular, rotating space station of radius 100vz 1)xg j14v2jog*rphc smnj47+k3 a b0 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 25 08oqnff4-9wobtpp c,g/o ppshvqns :q.3/ o )0 kg. It goes around a 13.7 m radius turn at 96.5 km/hs) c4pn/09nt 8 f :/ svqpp3who,qq.fo oogpb-. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to thzngmqld.od q,-bhab(o mk/s18t: z 96e end of a 1.0-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 the maxiqsgn, zqt9.:mh/b mzk- ol( od 8d16abmum 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 ve. v pkb)es n/ja;n3 ;rcf0u2jprtical circle of radius r. At the exact top of the path the tension in the string is 3 ;2v3 cr. ep)ub0s kan/;fjjnptimes the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled le5o5er4 y+zvin a vertical circle 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 rvey5o4+zl5e point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out qf nq/-/,*sb n.wwrulof the dive. What is the radi r //l* ,fn.nbwwq-qusus of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which t*jeb9y b,u.iqy gr r1)he 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 onr berybu19 y g)q.*ij,e-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand i,mc.;i-b-.dt01uix bdp) eq w phv4fc ce::jds about seven times his weight. What is the minimum radius of curvature tha.qc;- wufbexicdi:4t 1b.,jh)mp-e pdv0dc :t 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 horizontal curvb7e k*hewg*71c3 cqcjd btu bt )/-zw)e 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 fricti*)g e-wht1b)7kdecc/3jb* ub w tz qc7on between the car's tires and each road surface.)

  A car is negotiating a fl xkwv *ln55e l-zjsatho;dzqj-: 9v/-at curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by fril awzdl xqh ;n-5t--v ko9jevs5:/zj*ction 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 speed of 14 m/s.jeeb,b(c/ ciz l 9r ux-it*v:4wlgh(8 What must be the minimum coefficient of friction between the tires and the road for the car to make the turn?4 lxbjte8c-9 (lvui(c w:riez*b/h g,

  A car is moving with a constant speed v around a level curve. Th ds aof*bi8 q. jtcexl/27+q8je coefficient of friction between the tires and the road is .tsq*8jalq2+ibo7jf ec/ d 8 x0.40. 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 to negotiate3;7;fvkhez )3 szq6aw:pki tg a 100-m radius turn at 35 m/s without skiddinge:)z; f kqvhtiw63z3 kgp sa7;? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at grd;x e 35eh0da $45^{\circ}$ 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 t gy(xptob h0bhc3;839 cnkk45j u5 mp100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked aajz:y;2) sz m d;7k) bkgwub6jt $45^{\circ}$. 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 uniforml0 f/niafwf: 9dba-gpf oo1;i7y in a horizontal circle oa9gb aofffi/pf:w1;-o7i0n df radius 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, *gz o/.ge/beg0sulh y .;:*gn th.rad 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. golsd**/ .a.gg nhtyh bg.e;/ur0:e z(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 proton of z rj-m/l,h(gdt5.frj 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 per3v b72a*2wg+ig6gt1a ji-jc ;qt5qohp4ac qvson standing on the Earth, due to the cv 1t*2vcp6i4;-ojahw7t 3gq agqg+i ajbq52Moon? 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 3v*kpxd.aqv ezr75ot*m/j:n is F. If the masses are moved to h:ko3vpmxeq7rtv* z.5 d*j na /alf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the s;iys.makw kw.x .o : z;rd8:n af67er ak0m)aEarth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Eay.6an 7xfr0osea.wd; r ikksm ;kzm) .:8a :warth 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 i rfxpmtk, z/;7 wt s;y.;tktq(s $7.4 \times 10^{22} \; kg$ 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 distancel61 syf.gr 1-hsn w,rg above the Earth equal to the ryf6wgns.rs - g1lrh 1,adius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will x fs)7b (;uugathe acceleration of g;fu )7gasux (bravity be $4.9 \; m/s^2$?

  A satellite encircleslujdu+x08xu;q 2dk;f Mars at a distance above 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 the surfacfu;0dk+u 2jl x ;q8dxue of Mars, is

  At a distance of 14000 km from some planet's center, the acceleratio+ 6fn9nwh*cx un of gravity isf+ c 9w6nx*nuh $32 \; m/s^2$. 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 wctli 9kjs*;0 Earth has radius r. If the object is raised to a height of 3r above the Ea* wc;lj9k its0rth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chaobv5 9v ljtru7(l gv 9;v5l;dxnge when he goes from sea levvr7ll j;b5u9;vo(gd5t vlx v9el 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 kg is at a point 3r abovdmvujg3 on /i8nt+h 3cupi 984e the Earth's surface. What is the sate t3vpci9gon+jmi h883d4uu/nllite's weight?

  A spherically symmetric planet has four tiena8lk; wn ..fmes 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 surface of thin8ew;l akn.f .s planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, (k)d.tbt;j lhk yz5a4with the Earth between the Moon and the Sun ah 4yt.5()kb;ltj dzk. 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 tc+jy9oi3( dig7: z txgcy 0 duox+.jc:9 whv4ohe 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.,sd c-*1*xyt ahyl+7vs it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth iclvx+h yss 1*-ay *t7ds $6.38 \times 10^{6} \; m$.)

  A satellite is in a loa (jp78 m;soj4cf jsp(w circular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius ofm78( ajjjs4(p fso;pc the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surf5 n0 irp7r n2z1kyphm197dozhace of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mr0h1z rhnpp 9z52k7nod7yi1mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, haspxhw6:e i;*lb 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 Jb. e7qb.dwa3nupiter 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 plalr az vo)(;* l n :sjyn3v:g4qmdyr0c6e2:dqknet in nearly circular orbits. Moon A has orbital radius r, and moon0yqm 4g26zvoje:ysr l*nrn(;)qvlk: dd c 3 :a B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is/nsvzmid8 +t* $7.78 \times 10^{11} \; m$ 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 theint(1z(1u j5tv p cn/k Sun once. What is the average distance f/ttn511in( pz(jv u ckrom Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)