Is it possible for an object moving with a constant speed to lrj.mzk , ok2(5i5 wtoaccelerate? Explaio 5 5.j2lowimz,r (kktn.

  Consider a particle moving with constant speed such that its acceleration of y+spl dg:z9 l)qr 2g-wconstant magnituqdlw- )+py rls zgg:29de is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Cof.brtco.gy, ve )/ j ei) hpvuh9+4 st(,awo4dmpare the direction of the objecto4o t49w h s i,acf(,u).)vjtb .p/h reve+dyg's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direcul(i (8s-watjtion of the accelerat(- auw jlsti(8ion is

  Consider a particle moving w :-kaony1q d/eith constant speed such that its acceleration of constant magnitude is always perpendicular to its velocityd-a: qk /1noey.

  What type of acceleration doed c*6ghrr k,o4/cef.i s an object moving with constant speed in a circula6 *4/cdor,irh. gke fcr path experience?

  What force is needed toh+36g k ufj*se make an object move in a circle?

  When an object experiences uniform circular motion, the direction of the net / t9vdzq+ y+rzforc9t/y+dvqr +z ze is

  A roller coaster car is on a track that forms zuql7 n -6fzn0+jgf/s a circular loop in the vertical plannuqflz/g s0-7 + n6jfze. If the car is to just maintain 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 (m 9x5dph yfh0u26(h hsmass = 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 trackfu956 mhhys 2h0 d(hxp at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a ve1i*h //ug4n*u:y-pyo9s lg zxfum os7rtical dive then follows a semi-circular arc until it is going straight upxol/ 9hmgy:yu uso1in**p zuf-4 7g /s. 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 radiun /nx*mh1tzk tcy1c) .s $r$ 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:dp iqt0j :rx+kpvdy2-*myh. 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, compavym:r0q: *.h py -djptk+2 xdired to the first time?

  A car goes around a curve of radius r at a constant 3sd:zse:ouw18i2 71l qxebue 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 3bw lu2 ioezesuq 81sxe1:7:d the second curve, compared to the first?

  A car of mass m goes around a banked c6n,azav pbd4h+/tspp2j27d f6jo-keurve 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 road is equal in m-+jdks,appvhn b647t2ea/ f jp62odzagnitude to

  Two horizontal curves on a bobsled run are banked at tz1evkhn3ue8de c o2 - +(m:ydwhe same angle, but one has twice the radius of temk8n dy2 ue3-z:ow(ce h1 +vdhe 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 the Olympic bobsled track is nll f0ix/v;v r t/op,k-ot constant, but increases upward from the horizvrox -/ pk,vfi0l/l ;tontal. 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 o9mlt3 e, s5u0hfwina:bject moving around a circular path to have both centripetal and tangential accelerash5le u0fi9, 3ma wn:ttion?

  The gravitational force bwuesq-ml3+nap3du9+ji; n/ k etween two objects is proportional to

  The gravitational force between two objects is inversely proportional to8.ez:jt +yv emm g 49.lwrwf;d

  Two objects attract each other gravitat-k br3jz.:-retm6 nk qionally. If the distance between their centers isrtjkn. r z--3bk:m6eq cut in half, the gravitational force

  Two objects, with masses xx xqw-(( e/uv$m_{1}$ 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 g+c*q. ip y4c/(vne vm$m_{1}$ 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 m*tpk 6z p-3ve 5kvpct8n674bj )xrhuuniversal gravitation.

  Compared to its mass on the Earth, the mass of an qix6h:7 l/fbn byig 87object on the Moon is

  The acceleration of gravyq22 y30t uanfity on the Moon is one-sixth what it is on Earth. An obje3qty20 2nafyuct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rockemql6mb(kcq-4 t's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull ofnynf,c4 (yyu ) Earth's gravity?4y yncu)fn( ,y

  Suppose a satellite were orbiting the Earth just above the surface. Wha.0 ckmg+ 0uumgt is its centripetal agmg. k00u uc+mcceleration?

  A hypothetical planet has a mass of half that of the mj qxan2g+n-k9(eve) Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in tv gnaxj enm-+9q(ke 2)erms of g, the acceleration due to gravity at the Earth?

  The acceleration of uuactv1k 3jm*(0v i w9gravity on 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 mass compared to tji3 at*wc1u9 m0kvu(vhe Earth's?

  Two planets have the same surface gravity, but planet B ha0i58nuncmvu8s nsew ; je)0/my vp4u 9s twice the radius of planet A. If planet A has mass 8y9wu 5umsjsum ;i4 8c)eevv0p0/nnn m, what is the mass of planet B?

  Two planets have the same surface gravw.(qa/.em7 w ydy zm (53mjuhaity, but planet B has twice the mass of planet A. If planet A has radiz/wyeuw .a(hqm(am. m357jyd us r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r)x ,t9+ 9 gxnbie,qox9j4gctq+:auk)c .fwa+ f about a spherical planet (mass M).9 gfw qq)ki9.cfa:o+ ,jn+gbt a e4xxt,x9uc+ Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of sax4ye8jkt*cz) 9+r m40uwif xytellite B, and rotates in the same orbit. Compare the two satellite' ) +8m4utrkexfj 40c*ywy9izxs speeds.

  A person is standing on a scale in an elevator accewz)(pg dv;pd4b,k (pz jpj8w(lerating downward. Compare the reading on the scale to the perv;k4w(zz j j((p 8 gwd)pbpdp,son's true weight.

  Who was the first person to realize that the planets move in elln x ;f((xdu6rbr 5k6btiptical paths aroundf (kt ur6b;drn b5x(x6 the Sun?

  The speed of Halley's Comet, while travelin4re+o- 3+;skyiq akmjg in its elliptical orbit around the S3 saki k;jqye mor-4++un,

  Let the average orbital radius of a planet be R. Let the orbital period be 9 :ho8 d+ljmryT. What quantity is consto+8y:m h 9djrlant for all planets orbiting the Sun?

  A planet is discoverhub/2c, t swj4qe 7gv1ed to orbit around a star in the galaxy Andromeda, with the same orbital di47sewct2 v b, /q1ujhgameter 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 new planet be, compared to the Earth's orbital period?

  The average distance from+2 jpa.pw .s karw.u 1q1fku(b the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the aster 1(aa w w1+f2sprk p...ukbqjuoid's average distance from the Sun?

State Kepler's laws..vu n/ch wh(*n

  List the four fundamental forcesh4 4ebc jm3rw1 in nature.

  An object moves with a constant speed of 30 m4 kpsdpw0 sx:omtc4v*9x g:4z/s on a circular track of radius 150 m. What is the acceleration of p:4*d0o:p mkxt4 cxvz 4gs9s wthe object?

  The maximum speed around a leves/vbjxi0r/5 -h/gxt xl curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unc0/bxg h/jrvxtx /i-s5 hanged.)

  What is the centripetal acceleration of a point on the perimeter oemjf/zx)onzge ,,+ elz u l+)qo7 wz91f a bicycle wheel of diameter 70 cm wm qfe/e,u)9jnx7 oz1lzwe) ,+goz + zlhen the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s .3 *d1c iidi7em:iu0rg; oeav is located 0.200 m from the axis. Wha ev7mo; *g ia:dri 1dii0e.cu3t is the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space smn4a7qq qzl41 tation of radius 1000 m rotate to1m7q 4na ql4qz produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.v8zpmur e( p0 8b1/xohj6hya61 ,nj ri7 m radius turn at 96.5 km/h. Whatm 8b ,zji/hx pav6 onr1j8y rh6ue1(p0 is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The sy ;k- q5h3gab e1:iaqz9abkvv /stem is whirled in a horizontal circular path. I3e zaa- : 59bi/kvkvqqg1ab; hf 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 break?

  A stone, of mass m, is attached to a strong string and )vq (zo;ol35si9hax l whirled in 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 is given;5 (hosa)3 vxo9ill qz by

  A stone, of mass m, is attached to a strong string and whirled ine )itu,1i/wuy 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 point is giventiy/1u u,w)ie by

  A jet plane flying 600 m/s experiences an accelerati di0zi --w9xjson of 4g when pulling out of the dive. What is the radius of curvature of the loop in which ijd0x9w z-s-i the plane is flying?

  A pilot makes an outside vertical loop (in which the cenxs6 1(s vg7omrter of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down g6svsx17mr o(on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can1p;7k0oim1.iaha g op stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilo7.io;1gpi ma0aph1 kot, 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 horizontdtygv7yog+b9 / ;ei7q al 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 tires and each ryde+y 7go;7/vgti9 qb oad surface.)

  A car is negotiating a flat curve of radius 50 m with 1k/ r3x;t5,vtjn4 gc frb (svja speed of 20 m/s. The centripetav tf vr 4jns ;/rkcbj,x(tg315l force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cursh ;vnw+l5p9oww*hgg0t;bhj3 ehh 04 ve 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 twh9o etl0b j3;hn45s*hh+phgg w;vw0 o make the turn?

  A car is moving with a const6fb5g ,a yv2cnn nltma w9.n-+ant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minifwna56 +2anm9 ,bngltc- y. nvmum radius of the curve if the car is to stay on the road?

  What minimum banking an 7 g wtay8iw +wcyf(8ne6j)ft0gle is required for an Olympic bobsled to negotiate a 100-m radius turn aj6cy)agtw8ynff 0wwei( 7 +t8t 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on acv 55wa9n/o oh 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, banked at9gsas3 *(e e(u)hp cyd an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ba:m4zq -iyk)eh nked 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 revowe 8 qpnyr,+4 1mhq.omlving uniformly in a horizontal circle of radius 0.5o n1+mmyq48rq., wphe 00
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 ra fplyjp ,c: 2 j-hlvw0wz(6ve+ce car accelerates at a uniform rate to avvl20c:,pj p(+ywh6z eljw - f speed of 45 m/s in 15 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 consi5j2z/ *mib nkwsts 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 the Earth, due m/ h;hj 8;qmx+y8(qftxa*h hjto the Moon? The mass of tha( 8m q;8*+ f hyxhxthj/h;jqme 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 is F. Ifm7 5vk ,4ik+8wfrlhcj the masses are moved to half of i,r mwkl+c f78jvh4 5ktheir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at whaz pq9 )la;k2,5/uvbo qzl.oko t distance from the Earth willol )/z;kqva ol.29z5o ,bp quk 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 Moon i 6+bmsb(mj(jrs $7.4 \times 10^{22} \; kg$ 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 distanvmvn5cifh-v ,28pi ;ace above the Earth equal to the radius of thefn2-m8ipc,vv ah ;5vi Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distan dkf t7gip*mco+ /-1o4ttv)smce above the Earth's surface will the acceleration+ofdmskt*1- )o7vm ct t4g/ip of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above suw l9 2cq(anq6d+q w:its surface equal to 3 times the radius of Mars. The accwc qqws9 6lq2d+anu: (eleration 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 planet's center, the acce. 7zart 2bcv7 zurq5)lleration of gravity is2buz)5ac 7rvzrq7.t l $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the / swqmo qjz,1t85e1a esurface of the Earth. The Earth has radius r. If the object is raised ,qeoa mqz85j t1e/ w1sto a height of 3r above the Earth's surface, what is its weight?

  By how many newtons doen7 chy19c f 8-7yopegms the weight of a 100-kg person change when he goes from seae8c g7n179phcym-yfo level 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 sa4e81vs dku7f6n6ts y n, h6mdbtellite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weight68dy e,k4fbud hv n nm6tss671?

  A spherically symmetric planet has four times the Earth's ku.vf98rp 6s l*+vmdm;nrz;:6dht p vmass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Euhvdl.6r;;drz 98v pp6t msk mnv:*+ farth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same lmx:mzhe4,)hv z :cr: wine, with the Earth betwexc:z w: zhv,)hre:mm4en 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 transported to the ,9 b3b rmum )znp+pf *7oo,n/sy5 hqkwMoon.
(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 (m4mkwv2)t :)d;tdq*gljqhh,m 2bt s,i.e., it just skims the surface of the Earth). What is the ,4:2v ;dg mljtbdsqt,)k 2qt)mhmhw*speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit alw7me9 - juwn0bout the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution aronl wej-09mw7 uund the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 ,j3 w6r.jdllxkm above the surface of the Earth. It is observed to have a period of 89 min. xwrdl ,lj63.j What 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 orbitvpvbtm6mvpg0f 6( e3 m+8s q)bal 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 radiuc:nwkxh2nb r,gal,, +s 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 nyxhc9m.z d2 2orbits. 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 iymnc292 .hzx dt take moon B to complete an orbit?

  The planet Jupiter izheor 48uz*- o5fn7 tgs $7.78 \times 10^{11} \; m$ 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 the averath 1fw+tmt5 6oge distance from Jupiter to the Sun? (The distance from thet 6tw1+ht5m fo Earth to the Sun is $1.5 \times 10^{11} \; m$.)