Is it possible for an object moving with a constant s9c+8,jyfu6tq-t cophg ue4 .z peed to accelerate? Explain.ygt-ho zccqje +9,u4u 6ptf8 .

  Consider a particle moving with constant speed such that its acceleration of cov1sv32b+e 4dm2 uy)q/v coyhmnstant magnitude is always 3ou1m/2+s42yevvhy)m vcdqb perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the directi38/. pknemmc5v y klib5 rzh07i5kj0don of the object's velocity and accek85v 53kn5m0j7hlr/b d .m0pikyzice leration vectors.

  When an object experienclgy+5 5z-qa bwq.w+q yes uniform circular motion, the direction of the acceleratioqgy qz5 +wwya+-b.5 qln is

  Consider a particle moving with constant speemr l zs43dh)72/zkyegd such that its acceleration of constant magnitude is always perpendicular tos7y4 gmz d 2relhk3)/z its velocity.

  What type of acceleration does an object moving with constant speed in a circu n7;if /dp5zamlar n idzam/p75;fpath experience?

  What force is needed to make an object move in a cirux6hchc fb- v9r1q.sx3 2vae5 cle?

  When an object experiences unp/4qi xj7 tp+)o)nftliform circular motion, the direction of the net force isp4jx)/+i7 ) tpq onflt

  A roller coaster car is on a track that forms a circular lx cy*jtby47 v,roaq 3ejc1 p4m0-cx: woop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, j-m4e xp*qv4 3rbyw0c1,yc7 x cjot:awhat is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circula0qy / y-nu fb/eo2sqhz ic(j1.r 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 speej/chqn/iey uq 2( -0fb.1osy zd at that point?

  A pilot executes a vertical dive then follows a semi-circulm/+d0q,n)vl u (lxihdar arc until it is going straight up. Just as the plane is at qdu(hx+ l0/ in,ml v)dits 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 radiusbv1y:8znc) ks vtv4w0o1y9 4itl-isn $r$ 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 speezzcyppj6az7-g 6// hn d 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 /6p hjg7 pz6yz zna/c-around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constaphr0 4;o )szrlnt 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 the second curve, compared to the fir hsr0)4oplr; zst?

  A car of mass m goes arov ecn w 14l 84ub(pzmcw,.vfl:und a banked curve of radius r with speed v. If the road is frictionless due to icew l1cl,c( 4 .bf:upnwve48zv m, 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 on a bobsled run are banked at the same s2jqc*as. lj0r-met2 v9qh 7xangle, 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 jxtaqs2m*0.hv2l s7e9 r jq-csafe speed on the larger radius curve?

  The banking angle in a turn on the Olympicb9s5x-bimf-my) 5 lqc bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turmf-b5ci5bsxm-ly9 ) qn. Why do they do this?

  Is it possible for an obje kgjbts6m9v s5 u5)9sj;erry 0ct moving around a circular path to have both centripetal and tangenr)5j s 99mvks yerjbst 5g0u;6tial acceleration?

  The gravitational force between two objects is proportional twfn sh: k5f.e3o

  The gravitational force between two objects is inversely proportionzn dio3cjb*yaba -d; im0w3)-al to

  Two objects attract each other gravitationally. If the distance between their ajxv k::;td:( pxb*i)h.tpmz centers is cut ij: td*xivbxzh:.tmk () : pap;n half, the gravitational force

  Two objects, with masses ( ay, ci.-zcgld7ois:$m_{1}$ 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 masse4xgos*,akl p8 6jb3rk;l0o l0xdc7 czs $m_{1}$ 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 gravitationzwq;o 409 f er6pw7hrk *newx1.

  Compared to its mass on the Earth, thwgk j a*ram8z1bw,7 s:e mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is r03hdyf18 fvtr;k7qasuq254 as yj8 mon Earth. An object of mruv3a t5yqhrdysf1 ak2j8 m 7s4q0;f 8ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away + z i 1ojs4rqv/1beqf ocb+u/2from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pur5o,n qim/l; -dhi/kyll of Earth's gravimqd5;/yr /iolk- i ,hnty?

  Suppose a satellite were orbiti yef1r;om9, :mgc+oping the Earth just above the surface. What is its centripetf:ro oim,cm9ey +p 1;gal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twictw*jv .y bs8a)kj9 ;,7d*k bqb1auedue that oj* 9b;)dduk8 .yavjeutawq ,7bks1*b f the Earth. 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 Mo 9xelc r7k-lwy+ht5 7l 5q;pa 23vrncnon is one-sixth what it is on Earth. The radit pvae kn5 52lclx73r+r9;7 -qnwylhcus of the Moon is 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 thejxp ovav+ :7+p radius of planet A. If planet A has mass m, what is the mass vj pvxa:+op 7+of planet B?

  Two planets have the same /m)0c nocs-0 x;wdgh gsurface gravity, but planet B has twice the mass of pla /cg0w d-n)c0 hm;sogxnet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a 4kgy 7fvalr,zm/kl14 circular orbit (radius r) about a spherical planet (mass M). Which expression gives thi4gf 1 a 4kzk,ylmvr/l7s satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orb byid/o3sd+u.58kbm hit. Compare+im dd3.5s/u bhyk ob8 the two satellite's speeds.

  A person is standing on a scale in an elenl tq2*c6 3klevator accelerating downward. Compare the rn *l2tlceq6k3eading on the scale to the person's true weight.

  Who was the first person to realize that the planets movec),c r 7w z *gl)vhi.r*s:fuqp in elliptical paths around the Sgpsu:z )cr* )qf . *vh,ir7wlcun?

  The speed of Halley's Comet, while traveling in its elliptical orbi kmwno qk59m.1/ ;iwuot around the Sun,wm5i;/. onkm1 qouw9k

  Let the average orbital radius of a planet be R. Let the orbital period be T-fx gqy 2w42ly. What quantity is constant for all pla42gql2-wfyx ynets orbiting the Sun?

  A planet is discovered to orbit around a star in the )pph 8t/lhlb)np uvu-ey .e de.qm(; 8galaxy 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 new planet be, compared to the Eart; 8 . e-l)/e.ppvqnypuu( b)mhlt8hd eh's orbital period?

  The average distance from the Earth to the f6i(wo,bl*q nSun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's averbq6 ,oinflw (*age distance from the Sun?

State Kepler's laws.3 sgk n a81o(3- smghpg 7wssim8/+ahh

  List the four fundamentalbfvl-v,-u1 * pwo8 vwm forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track ofwf 6cd vm-gg /a v79/wuvy4pr0 radius 150 m. What is the acceleratvcw6p0v 4vya 9dm/7 u-g/gwfrion of the object?

  The maximum speed around a level curve is 30.0 km/; owhyd-qt+9a;pnmg: nua7-l h. What is the maximum speed around a curve with twice the radius?nwa-9odl7y ; ngq-p:hmatu+; (Assume all other factors remain unchanged.)

  What is the centripetal acceleratiof6 cxdq0gk62s+(j rjan of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movks+6 c2qg xj6jd afr(0ing 8.0 m/s?

  A point on a wheel rotatef bq6+w:+c njing at 5.00 rev/s is located 0.200 m from the axis. What is the cen:+ +6bfe cnjwqtripetal acceleration?

  How many revolutions per minutq s4gv.p-p2 k+wbcx* ae must a circular, rotating space station of radius 1000 m rotate to produce an artificial grp xsgbvc2.q-+pwa 4 k*avity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1 ydc62xwku-h16 jch4c3.7 m radius turn at 96.5 kd6y c 6cu- w2c1xh4khjm/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whab ch n8av* ck09vvf1je 1ht7(irled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mak( c 9fn0v8h7jeb1c*tavh a 1vss if the string is not to break?

  A stone, of mass m, isx1ovo0 *:mjaai :3kvq attached to a strong string and 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. Th*: vokiq:v 1o axj03mae stone's speed at this point is given by

  A stone, of mass m, is attached 6v0-b cy9kzz ;nzj2g en2r*/rn s.jofto a strong string and whirled in a vertical circle of radius r. At the exact bottom of trj6 jyz;c/2 9.vfsrzb*ngeznk o02n -he 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 acceleration of 48aan3h k( vkc:g when pulling out of the dive. What is the radius8 :ac kvha(k3n of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the fyx ,pi(roy 8n;e;*;q 3ycee2oyb w:r 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. e: r xo;o r8i;(yywe*enfy;3b,pycq2 How fast is he going?

  The maximum force a pilot can stand is about seven timm +u-,aexz jn1es his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vu- a emjxn+,z1ertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m r f. 952hs/ zvqyhf+mgpadius horizontal 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 coefficienthm5qgvhf.z2 9/ps +y f of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve ov/ yyihq9l,2.e )zup .v 4obypf radius 50 m with a speed of 20 m/s. The centripetal force provided by frict4.e/lviz.q)9yy,op vb p hy u2ion 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. What mm2u3an)r 8g m-x bv*fj*i(updz-x pg( ust be the m *ga (mm(pu* xrp- 2vgbi) zfd-j3xun8inimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a levelf3pr: 7ef7c(2lpxg wo6rjo6 x curve. The coefficient of friction betww7r 6ppl2(xcfo6o3 7fe:rjxgeen the tires 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 required for an Olympic bobsled to n/dyxc9uf dc9r62m: y fegotiate a 100-m radius turn at 35 m/s withouudydfc rx9m 2/9f:y c6t skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is 1c69 srlygxx,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 myrxf i tt(wcv57:;6d 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m isqave 4n+k 8n2wh i 7iglog(uazp*-3r: 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 a7hii ;84cw 4tkzz y5ie string is revolving uniformly in a horizontal circle of radius 0.5 zce47hkywi4 i;zi8t 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 accelera3qyqxq; s (vs:(e/q nhtes at a uniform rate to a speed of 45 m/s in 15 s q qy(svqneq(3hs:/ x;, 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 of a proton of majo2qzykq5m 7x 5g7hosbf3q. 9ss $1.67 \times 10^{-27} \; kg$ 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 Ear*wplg+kr, s -hth, due to the Moon? The mass of the Moo-kpw,s*+gr lhn 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. Izj.gkf529 p2a * rcfn sm(3gauf the masses are moved to h2ngaucs*( 5kfm rzgj9f.p 3a2 alf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from2i1y zyzb;(bm the Earth toward the Sun, at what distance from the Earth will the gravita;bbmz y z(1y2itional 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 Moonhssqvi7kr+d16lg..ee fh .i2 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 above the Earth equal toh r3p v:hv s 1.5uufij/,b84ffzzap(m uh,i /zvf maz(1:8p4bf5vjhuprf.s3the radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Eau jrso* m1 zpa22* cw2)ahhap5rth's surface will the accejh2* p5)am1ar u* wsh2poa2c zleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above icgd zyqfz7cf,(c498du3un f)ts surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as co)7(fcu ycfq9 dz348 ,duczfngmpared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the accel rb+(mcl4cx h:gwz)4j y/p 6sleration of gravityybglcl44p+j w: /6) csmrhx(z 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 b0;t lns0*8 hc vghht7Earth. The Earth has radius r. If the object is raised to a height of *s08n v7ht glhh0t; cb3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goesch6 ydo7t1.3 n3ikpir8c p-pp, xysz8 from sea level to an altitude of 5000 m? (The mean radius of the Earthi8op 6ch3pd. pnyy1cxs8 ti-rk7z p3, is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above j8.ub,bg7wb3 q hvu 3df*r2jjthe Earth's surface. What is the satellite', j.7 j r32bfh*d8gqbv 3bjwuus weight?

  A spherically symmetric planet has four times the Earth'syq2b kv5k/n agr/(1 dk mass and twice its radius. If a jar of peanut butter weighs 12 N on the sdqr2akyb/(kk5 v1/ng urface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all x(os5 qfz5ujco: t, l+lie on the same line, with the Earth between the Moon and the Sun.+ sx q(ot5ul,5c:jzof 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 Mo9yf-/me wv7hkndn 7q-j3i,vv on.
(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., i;o 2pv2ams a:mt just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of :a;v2ma 2o mpsthe Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit1qd 9 nlhs y+lobg(b6xog31v1 about the Earth (i.e., it just skims the surface of the Earth). How6 1gy1b9oqodl(+gnx 1s 3lh bv long does it take to make 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 surface of the Earth. It is ox 0o :46ieg fngu:ac6rbserved to have a period of 89 min. What is the mass of t egx:6g:o0n fur a6ic4he Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametn6bd7w) sxdkj o l/n9lz b3l(8er 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 radius ngsfsy2pa 1w;jcu: o55 +)r dfof $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planetez,yg3gm /4 cd in nearly circular orbits. Moon A has orbital radius r, and mooncgz3/me,gy4 d 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)piqs f 71j i9q44slms-zfd 8s $7.78 \times 10^{11} \; m$ 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 isjntx+ln0 1r y- the average di1nj-l rx +0nytstance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)