Is it possible for an object moving with a consta27/y:qvx zccp nt speed to accelerate? Explaiqzc yp:/7xc2vn.

  Consider a particle moving with constant speed such that its acceleratifg19vv2 sockqjkf l6:k v3 k,hel ;s76on of constantfls h;ko2fql v7e:96gkcv31jkv6sk, magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare ikgqwjuz, *,* n:lvp/1-jz qs the direction of the object's velo: n/jzi*,vlu ksp1j *,qwz -gqcity and acceleration vectors.

  When an object experiences uniform circular motio8f,*s tn i;lq4hnw+ap n, the direction of the accelerat+nnapfit8 4 *lh;, wsqion is

  Consider a particle moving with constant speed such that +lpt3tf4. k znits acceleration of constant magnitude is always pez tpn .f+t34klrpendicular to its velocity.

  What type of acceleration does an object moving tq0au 3o qc; 9/t y/-lvfqna*owith constant speed in a circular path tlco0-;/n/u y3*9fa qa v qqotexperience?

  What force is needed to ma);b4rjnh,zns *d xsu (5njt.qke an object move in a circle?

  When an object experiences uniform circular motion, the direction of the nn*7t8 a *cwc oo l :bk,iipsm*rb1q/z3et forcz *lcm:c*r w1 7bp*i8qab,o3nstik/o e is

  A roller coaster car is l88hhnc 1/u jdon a track that forms a circular loop in the vertical pl 8l /1cdhjhu8nane. 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 (mass = M) is on a track that forms a circuyb*6vmaw/,9b4 zuxev lar loop (radius = r) in the vertical plane. If the car is to just maintain c64xzw/e ba vby,uvm*9 ontact 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 folbk+l4 sqp6a)blows a semi-circular arc until it is going straight up. Just as the plane is at its lowest pop 6+qs4lb ka)bint, 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 os36-h ;q -y8 uzahgullf 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 bell 6*t, q+ka zsg9/yspeed 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 curv la6q+ 9t sg*z/,lkeybe for the second time, compared to the first time?

  A car goes around a curve of radius ,n;j(lh5 cwyo r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What iylj5,o (cn;whs 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 v. If the rogvzrf,bt ynyzj4, p;20-j zjrxqj5 / 5ad is frictionless due to ice, the cazpyy zj5 jbx0,v5- ;t2 zr/ njq4rfjg,r 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 angle3;a q:jgr lka4fvn67 e, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius lk7f:3g a4jqr;ve6 nacurve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsmhffkm ypfe)f +()0y( led track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," thenf(kh )(+)fy0fepm fmy go lower coming out of the turn. Why do they do this?

  Is it possible for an objectm:ty/2lzp0* lx )v vplxh)jx3 moving around a circular path to have both centripetal and tange230 zly)tp/ hlx vj *plxxvm:)ntial acceleration?

  The gravitational force between jui4*yi h xb6 wp-g1/btwo objects is proportional to

  The gravitational force between twv7:/ri s umt*ko objects is inversely proportional to

  Two objects attract each other gravitationally. 1je)xn ey6pj3.ohb 3m:ptv 1 nIf the distance between their centers is cut in half, the gravitationaltm3en) 1 o3xej.y :vpj16bnph force

  Two objects, with massesw++x ewn. 6w0jh deu 2ur(mm4f $m_{1}$ 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 masft3rava , :uc3ses $m_{1}$ 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 univei (dk-nbd9oq ua *g ,aqa-88v(nvrv-ryh4cp)rsal gravitation.

  Compared to its mass on the Earth, the mass of an objecx 4t jk:ye,b8nc.jr)j t on the Moon is

  The acceleration of gravity on the2tcua t z9,qql7v;iq6 Moon is one-sixth what it is on Earth. An object 9zat;tlq7vi2qq 6 ,ucof mass
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 w tj1a l4qq*yq5eight

  A spaceship is traveling to the Moon. At whatp7q rx8 x)b 9k4bt-rah point is it beyond the pull of Earth's graapb qkx-x98r h7r4 bt)vity?

  Suppose a satellite were orbiting the Earth just above the surface. What mbp jb3c4 .m /h9qf/ybis its centripetal ac3 mmb4hbf/9pby j q.c/celeration?

  A hypothetical planet has a mass of half thas+ xsfb1x1 olryk8l 5pv8 u)w,t of the Earth and a radius of twicexyw5uk8)18ox,sl+rf b1pl vs that of 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 Moon is 6vpa9 a 3k0 l;8(dlsrwnu/ apjone-sixth what it is on Earth. The radius of the Moon is one-fourth tha(lv0;npkjp 3rau89s ad/la w6t 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 the radrs 03c454ll yq1d0)wh3nzwhtd ii3g dius of planet A. If planet A has mass m, what isl 1wd scgi0r nyi q )d4htwl033d54hz3 the mass of planet B?

  Two planets have the same surface gravity, but pl7 8pwbb95a wutanet B has twice the mass of planet A. If planet A has radius r, what is the rp 7tb8w5bu wa9adius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sph(w2bdcl+u eoh4od i;/erical planet (mass M). Which expression gives this satellite's orbital veb2uil ;+ oo/dd4(hwe clocity?

  Satellite A has twice the mass of satelliteyv )qad4.e/y13t a ivv B, and rotates in the same orbit. Compare the two satellite's spe /a4 qy1dvv. ivye)3ateds.

  A person is standing on a scale in an elevator accelerating d*)l4d4g n;c pghz4qt xownward. Compare the reading on the scale to the person' )tn* p;xqg d44glchz4s true weight.

  Who was the first person to realize that the planets move in elliptical pa pj-/h56zh ega2.yo 1ro)elhaths around the z2 hj o6rha. e 5)ylh/ag1op-eSun?

  The speed of Halley's Comet, while traveling in i5i k:dd (veell33f2 ,bnrrzg59y; yxr ts elliptical orbit around the Sun5rx f i2eddy r ey3,v5n9:lkb;l(gzr 3,

  Let the average orbital radius of a planet be R. u qo4ml+gwruj3utjp;g7g n7)y qpy 7 -1x**qe Let the orbital period be T. Wharjqxg+7moyu 3 lwt p* -g)qjnug ;p74yqu7* e1t quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the zeh0a.qr;60o3 py ekr +nk5epsame 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 e k a6poeh.;qy ep05kz+nr30rthe Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomicnu gdxfe17 xs82;qlm9 al unit" (AU). An asteroid orbits the Sun in one-third of a year. What is 2; gs9dm1fu7 xnq8le xthe asteroid's average distance from the Sun?

State Kepler's laws.o2bhb b1mfh* 0

  List the four fundamental forcshrtj 6bbgy26 n :c05wgrn8vf*2 d-b qes in nature.

  An object moves with a constant speed of 30 m/s on a ctjj.j* -zw8/z.mn ijs0in6o nircular track of radius 150 m. What is the acceleratio* iz.i/z- n w8s0nojt jj.m6jnn of the object?

  The maximum speed around a level curve is 30.0 )sqve chu,8t:cmz:p(kjw*s7 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.)j,hs k* ) v(:cpt7:mwc usez8q

  What is the centripetal acceleration of a pkko 0fy/plnew)29, o toint on the perimeter of a bicycle wheel of diamf 9ko)ek /y2lpwn0t,oeter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotatirdz jt3 ghcdp4..3t-qng at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal acceleratio4j.ch -tgdz3q t3d .rpn?

  How many revolutions per minute must a circular, rotat0kydj1q qma82 ing space station of radius 1000 m rotate to produce an artifad8yq1qk j 2m0icial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1 lgw)0uavb8(pi s :a5r3.7 m radius turn at 96.5 kms(awr 5pi g):0l8vaub /h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0/r5g/ q-bj( aw :-uwqct:e ;lq0lsxzm-m string. The system is whirled in a horizontal circuw q gm-cx uqj-str(l05wb::l /eaz;q/lar path. If 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 toqz su: nc0j1/l 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. The stone's speed at this point is givenqj/ un1sl:0zc by

  A stone, of mass m, is attached to a strong string and whiru;ktjr7 ogc lf-;om67 led in 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 isto -7m6gf;j7o k;crul given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pullinklw a1c3 j :20;khqwnwg out of the dive. What is the radius of curvature of the l 0aj: h3w 1lnwk2wkq;coop in which the plane is flying?

  A pilot makes an outside vertical loop (xuqldll47 d,- in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing dow,ud4lxl - d7qln on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand7:ee l5v4qcpktg ik9djx.. : v is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 5v g9:tdkjq..7cie 4k l:p evx250 m/s?

  A car traveling 20 m/s rounds an 80-m radiu +nz j+h+q:ioos 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 coefficient of friction between the car's tires and each road suhnzo+i+ oq:+jrface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 j 6k *bdxo3ga,y;v;rnl78 nzcm/s. The centripetal force provided by fri xjy38,;7r bvzcgl6akndo;n *ction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiusx0tb,1zj*qmwbl jm+ . 50 m at a speed of 14 m/s. What must be the m1m* +x,tjqj.wzmbb l0inimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a consta3gjaqu0m3b+d )g.c ugnt speed v around a level curve. The coefficient of friction between the ti +ugau.mb)jgq 30 3gdcres 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 Olypilx;a+0o5ns,iej 1 ompic bobsled to negotiate a 100-m radius turn at 35 m,e1ai;snoi + x5 pjlo0/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run,,lb yvjz /b 4n7yvsy8 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 a /erate2mqm; q uz-0f.t an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at9chghp* b2h x, $45^{\circ}$. 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 revolv)8r cu(+q bz1 doyxw*q q/uel:ing uniformly in a horizontal circle of radius 0.500orqqu cx )zb/l+e:d8yuw(q* 1
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 rs7 ato4* woa cwvm:oj1*;s9mq ate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fi;49* oaqa jvsm t*mc:wwo7o1s ll 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 of3ct9tf+7y opid32j5 xw(acu g 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 personemjy/; le/ ( igo64p( fln:riq standing on the Earth, due to the Moon? q pirfjl( / ;/ym64eigl(:o enThe 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 is F. If the marjg.* 9w( q3b, qqtpwisses are moved to half of their initial distance, what is the gravitational attra9w iqp. b(*rqwjg3qt,ctive force?

  For a spacecraft going n-8lfa s nl14qfrom the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cannslq 8al4 nf1-cel?
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(h srj p/o1rq5sxf--t+*l e nu 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 "n,*qx qbgb199ja el3n t69l arspace-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravitx19a, 969tbglnqaq ljb *n3e ry?

  The radius of the Earth is R. si.(e egi a7n-At what distance above the Earth's surface will the acceleration of gravs7 e.e(-inagiity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abo3yd57 emrj d .at5 +tlmp8jkp;ve its surface equal to 3 times the radius of Mars. The accelera73;ed l+m5p t. jry5jtmk8pad tion 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 acceleration of gravitydeyldr)r l;2. xc3(y. 3f fcvv is 3d2ye)3rf .yl cv.;vxlcfrd ($32 \; m/s^2$. 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 Earth has o d:wdte,9l. 5we/ eezc ;t4eby4sws;radius r. If tdw 5s ; db;l4 y:w4/stt9z ee.ceeewo,he object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does thosp/w0hk 7r w),lw8 n0nj 5ohme weight of a 100-kg person change when he goes from h8jpk lw5)h n0wor/ now7ms0,sea 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 satellite of mass 100 kg is at a point 3r above the Eapbxed+ z-y7 /m j0yg.yrth's surface. What m07j-p+.z xdbygey/y is the satellite's weight?

  A spherically symmetric planet has four times the Earth's massdt2 o t;22wip0nwh ds- and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it we2t-dwi w;ntsdh2 o2p0igh on the surface of this planet?

  During a lunar eclipse, the M8n h.alv6mf. p29gpag oon, Earth, and Sun all lie on the same line, with the Earth between the Moon av pgpamg89n6f.2.hla nd 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 thevoe4( b-(ki gr22br.tf0 r8.2nh e4tmec kigi 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 (ipus2uj,5 l2dqwydw pip) 25k; .e., it just skims the surface of the Earth). What 5)u2y5ppps 22 ;u jl ,qwdikwdis the 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 about the Eartyqp--3cl9hs 3j k v7x uaeu(q2h (i.e., it just skims the surface of the Earth). How long does it take to make one rev9 3q( l-h2pksxvecu7 a-3uqy jolution 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 surfac msvpnyq1-x 4+e of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (-yxpsv4+mnq 1The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametej3z)cl 5et )egr 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 orbitsne2dk:ia /scn s52 9qw 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. Moon A has orbital aiq 2heho( hx56f4 8xrlp)cdu ee+.v/radius r, and moon B has orbital radius 4r. Moon A takes 20 days tdqva 2hece )xx(o h+48e56p.hil r /fuo complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ism*mg+tc 2a qg) $7.78 \times 10^{11} \; m$ 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 jg wbo+wkx:wus82 b:6g/zjjxr 88 +ocSun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun is w:wow+xks2 +:b xoc8rjz j88jubg6g/$1.5 \times 10^{11} \; m$.)