Is it possible for an object moving with a constant speed to accga9i4 m8.qun zelerate? Explai.9a m4nzqi 8ugn.

  Consider a particle moving with constant speed such that its accesccxf;21sj3.)vxy1a o ak eko2 kh5- rleration of cony h1rfe2x)s-k cxkoa3sao.;1jv k2c 5stant magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant spe;i.x7kk fd*xu/ 3s gxued. Compare the direction of the ob k.x f*k/gxs;x du73iuject's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the diree /a imq:-hxx*ction of the accelea x qx:hmi*/-eration is

  Consider a particle moving with constant speed such that its acceln uvwvd.b.a6kru5 2rb,zb9 ,heration of constant magnitude is always pe5bk,n hbb6v9uawr.2vu r, zd.rpendicular to its velocity.

  What type of acceleration does an object moving with constp9 4b6eorgj g5 sqnf x p,7pmoi,4+4r yqat8h4ant speed in a circular path exper 4n764jxo +amh,p9 q q4syrgpf4pb,8o 5ertgiience?

  What force is needed to make an objow. b:x/ u 7s(u,dmoci:tcl67b p4innect move in a circle?

  When an object experiences uniform circular motion, the direction of t3 5y;. tmw1a(nc:gzj 5cblaw rhe net force isjwt ya nc5 1:z rwaml5(g;3b.c

  A roller coaster car is on xbc* z6ixy ;/4 zxbw8la track that forms a circular loop in the vertical plane. If the car is b bxw;i86y l xzzc/4x*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 (mass = M) is on a track that forms a cir:w,egwgw pn 64cular loop (radius = r) in the vertical g4wwwp6:, ngeplane. 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 point?

  A pilot executes a vertical dive then follows a semi-circular arc unt7uf26jbukavu3ep ne f))39 y;lsw1o cil it is going straight up. Just as the plane is at its lowest point, the forc julvb)uaw 32pek3un) 9o6;1y7e ffcse 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(,te* tslcgnv/0 qhsv(bc( a ti d3x:,pyy)w; 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 spe*m 9hpjp 4xhodr+*f 8jed 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, p 9+h4m8op **dfhjr xjcompared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it go*f5ij jl9 6nwcoq7yj i/sy7 kq,l x,2yes 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,iyj6kyqqo/2w9 nl5fs yxli 77j* cj,st?

  A car of mass m goes around a ) qc g:f9;tqewb+4i ifbanked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negoti+;)eg :fiq t4wifb 9qcate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves bq s1 n9pel*hid8cu)3 on a bobsled run are banked at the same 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 th9ql 1i38nes pc*)hd bue larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not1jlsnlxt/i2 wsgs8 2 t1 l,*ft constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will 12tw/lstix glsjst2lf 1,*n 8 intentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object movaq9pr 8go6y jv 5d7ah2ing around a circular path to have both centripetal and tangential v 67ar92 8ydj5hqo pagacceleration?

  The gravitational force between two objects is8dz,j(qxo 6se proportional to

  The gravitational force between two objects is inversely proportion/va7atdj 2 4hzb(/l5*egbkhsal to

  Two objects attract each other gravitationally. If the 0,1ju:; kjkuh p;kurp distance between their centers is rukk j;:,u;pphk1u 0j cut in half, the gravitational force

  Two objects, with ma67+)ynq ;n(gry lrbju,gy9miq *(v bssses $m_{1}$ 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 mau:7p hkd*yb 5nsses $m_{1}$ 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 graviz)* cgfe/xm-1v7d.7tt tb-spgz j y8ttation.

  Compared to its mass on the Earth, the mass of anvglbg 3 k*-6vg object on the Moon is

  The acceleration of gravity on the Moog(n (3osl 0tnt sm1fo)n is one-sixth what it is on Earth. An object of t3o1lg 0n()om(nssf tmass
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 weigck mc6cul a j0h568rm8ht

  A spaceship is traveling to the Moon. At what point;)jjs:xss3 f rge34sfl : y6zo is it beyond the pull of Eartfezj:s;: s3sg 4syr j)6xfo3 lh's gravity?

  Suppose a satellite were orbiting the 2i gx./ 6/b:rw9leur3 lfwcow Earth just above the surface. What is its centripetal accew2eo6i r r./9xwlb wu:lc/3fg leration?

  A hypothetical planet has a mass of half that of the Earthd, ,g qwqe6e0p;rfu+r and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of gqpfrgd+wu, 6e0r ,q ;e, the acceleration due to gravity at the Earth?

  The acceleration of gravity on tejha0 zzd -21whe 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 co0azd2e -h w1zjmpared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of s6 ybd zjz(+/yne,xk2 planet A. If planet A has mass m,y2z(yjdsb+ ne,x6 zk/ what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice thml10gesnqic +r* vvgqg:n/in 9q s+-(e mass of planet A. Igg*/r-9+qlnin mvs ci g:qev0q (1s+nf planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius swhr-;3olhz1,(p. l g2gapw 5y6rt f nr) about a spherical planet (mass M). Which expression gives this satellite's orl lhpn2(5g .z-ryf6hs3wwaot1rp g,; bital velocity?

  Satellite A has twictysg 8ho vz ;l;acwb/uy,a7:-e the mass of satellite B, and rotates in the same orbit. Compare the two satellite's spey gvz,o y l; s;u:b-/8w7acthaeds.

  A person is standing on a scale in an elevator accelerating downwax03ku vonu 4f7rd. Compare the reading on the scale to the peu n04k7u fxv3orson's true weight.

  Who was the first pe+ 5xs(hmuxznu 1 4d(lhq:-t rtrson to realize that the planets move in elliptical paths around thh xn1 - qmrux((tslt5h+ uz:4de Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit 82ex pq-ko7g8o j-*s z2gjljparound the q o7g22--j*kg p8s8xp ljje zoSun,

  Let the average orbital radius of a planet be R. Let the orbib,m xtb*:5bpoa (, ).tjjiv4bd ywht:tal period be T. What quantity is constant f .mvjd b,(4 ,txb5oti: w)btyh*pb j:aor all planets orbiting the Sun?

  A planet is discovered tlbe, 2/jxrwl.p 0 3fjvo orbit around 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 new planet be, compared to the Earth's orbital r0 px b2.,je/w fl3jvlperiod?

  The average distance from the Earth to the Sun is sbk9 0tbyp s4e4ad*1 ye/.te gdefined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroask9e .*yey/ e0tbg14btpd4s id's average distance from the Sun?

State Kepler's laws.kp98aw 1)3g;0ais/bdtz k ch wg06giu

  List the four fundamental lu.;mt9t5(cq 7xke ufpiz8r h.8m3za forces in nature.

  An object moves with a constant speed of 30 m/s on a circlb0dh+a;c t 5hular track of radius 150 m. What is the acceleration of the ob; hbl0ahcd5t +ject?

  The maximum speed around a level curi0z+icpt ;uh19 km+i kve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all otukph +iz; 0+tic1ik9m her factors remain unchanged.)

  What is the centripetal acu lsh5. oyi2h 1k6kmqi7 qm4c5celeration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike islcho 2kq4i6ims.ky1u h57 m5 q moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. e,/ht 73ys6mul wo6;u0avrzz What is the6oze mz3a6rw; su7,/uvyt 0lh centripetal acceleration?

  How many revolutions per minute must a t;4e-pcn4stu gxk z. x c)if05l8oig -circular, rotating space station of radius 1000 m rotate to produce an a84x p u4xni 50egcfls-. ;)toiczgkt- rtificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It6trjmd9g l84 r goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on jgrr9 6mld t84the motorcycle?

  A 0.50-kg mass is attached to the0k qpe *hwt vg,n7vo6* end of a 1.0-m string. The system is whirled in a horizontal circular path. I*6kwh7vgeoqn 0v pt,*f 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 attahi)s0j ,tc55 ,b jgvt 6s/scyvched to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in )t jg,c 0sv5b, ih6s/yctsv5j the string is 3 times the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, is attached tkpu+g 3 ,rdvk4(l w gy:5o9gxro a strong string 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 stone,4 d uly3k r9o:rkv(5gpxwgg+'s weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an ad p(min*c5o +k6gzb-v2 42hel6djl jlcceleration of 4g when pulling out of the dive. 6mlogn*ehi+k2vj2d6 4lpj-5cb (z dl What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which tbzcm nwv iq49m;qiw9zx48 .c* he center of the loop is beneath him) of radius 39xw z8*wzb4q cc. m nv;mqi9i4200 m. At the 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 stand is about seven times hgbm7a2 :1hxgnmndv 1 49rwix5is weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a g54ximd7an91vx:gnh m 21b rwvertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires lx.2fpryxp /rt *bz1 +on the px./l2z1fp * + ytrxbrverge 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 road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. Tfuds5 -s+sz -k:zbdzf8s8 7 brhe centripetal force provided by frictsd 8:8 sz 7u5f-r z-sbksd+bfzion 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. 2/u stqcdhe-7h )3f cm9ei um: What must be the miee f th -cm): h/7icmsu3d9qu2nimum 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 level curve. The coeff3xhuz ,a/x vy -tivy5:icient of frictiy,:vta iu3 vzx5xh -/yon between 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 requivm+h b4)rrl-hq0 s x,ired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignor)xr hbshlv-0rmiq+4, e friction.)

  A horizontal curve on a bobslapj/*14ei/d b )hpef wk.h 3vaed 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 at an angle ofacvyaw+q9 e-( $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m il u bn1e0( c.bobmk*e0z zb6y+6gm.k ys 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 dw8 7z ;78dbqimvq ,bwend of a string is revolving uniformly in a horizontal circle of radius zw8qq7d w78i;db ,v mb0.500
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 u-waqrkweeeb 6zu 3)a1k44 w 6xw6 px8to a speed of 45 m/s in 15 s, moving o 6 3a )b4w6 reee8a4 -wxuwxwu6qzp1kkn 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 mae i8nrfpr(9tvr9d 8h :g o+0zuss $1.67 \times 10^{-27} \; kg$ 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 per*:iq aru .vo azfs+vh;(nw6d; h6e 17t on5mynson standing on the Earth, due to the Moon? The mas.ahnf;u:aevqt d7(z6 6m*os n wy rn5;1+hvois 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 is F. xzz935* kuep0s+ zpo 2 kdrp*rIf the masses are moved to half of their initial dist2 p5kx*+ s3 ropuz0kzrzd*pe 9ance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from theazv n,n- 6yf/zwox3udd.+le . Earth will the gravitational forces due to the Sun and the e.f/,d +6axulwn3.d- ozyznv 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 ik .qdu9wg-l(t 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 distance above tq1 mqm+/zh89u f;s uxthe Earth equal to the radius of the Earth. What is fxqmh+ 19sq/;ztum 8u her acceleration due to gravity?

  The radius of the Earth y4)qkb **h;, zcorgw4rr2zn9n gu0lh is R. At what distance above the Earth's surface will the acceleratioh* 9z4kzgq u l,y bhnw240rocr );n*rgn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its ss+tnh r03bwx7urface equal to 3 times the radius of Mars. The acceleration of gravity of the satelsh+ x7brwn 0t3lite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet m2 qhnb3swi/phi c*8,'s center, the acceleration of gravity is m/h3i 8hw i2sp,ncqb *$32 \; m/s^2$. 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. b6blbv i4 xrcq3yo2 mn8(82 nqThe Earth has radius r. If the object is r c242o8(bmb8in lyq3qx6r nvbaised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weox4 qf ;eto0,fight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The meax,fe4;of 0 qotn 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 poins:c*4 nhccmxzo7 c5.z t 3r above the Earth's surface. What is the s4zz.xcc5n *7:c s comhatellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice -bx;igu*cln,its radius. If a jnbucl ;i-,*gxar of peanut 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 l4-6ej) 7ab*nqiq f(qvgpbuc. ie on the same line, with the Earth betwee pc)va qun.eqg(*- iq47j b6fbn 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 ,( x7.-zdu eqas/ubfq transported 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 Earhr.3x;jbi t4m th (i.e., it just skims the surface of the Eh;rm tb.34ix jarth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cilsty-*shviae /; 5sj 2rcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it *v jeit /s;a s5-lys2htake 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 isvw9+jt fmqx)jt78cbfhb )*b8xg 31 rn observed to have a period of 89 min. What is the mass of the Earth? (The mean radiusbh 8v* 8j+rj)7bcftqmw)x 9n x3b1 tgf of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiwy hn9-j14l ycr1v c0oter, 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 orbiwdsm 5(i f nhv6/)mq17ywy* zlts 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 planet in nearly circular orbits. Mo 2 o*iyb ,tultohl:xc; 7)8zhkon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. Htio7 :lz;* hh8bktox y2)uc,low long does it take moon B to complete an orbit?

  The planet Jupiter is ujnr8lxz v,nj28 , )tu6cj7gp $7.78 \times 10^{11} \; m$ 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 2kz ivrxgsub4 1 o/a9p1s9x:9 xpzby3Sun once. What is the average distance from Jupiter to the Sun? (Th1au1 krxx9o bsbziy/zx 3g2ps 949v:p e distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)