Is it possible for an object moving with a constdeycem+gf 1y946ou 3 qant speed to accelerate? Explai yg 3 qmee4+fu16y9docn.

  Consider a particle moviq smd(nryf;-df3 u,vnyh:w7r. p0 k*cng with constant speed such that its acceleration of constant magnitude is always perpendicular to its y(fr:wnp 7ku;n 3-hsyvrfmd.dc,*q0 velocity.

  An object moves in a circular path at a constant speed. ,marljvhuf;ril 2i3 (l :w1z t51 es1i Compare the direction of the object's velocity and acce2e, rzl1;mi hlii1uv: 1ta5(r3js lwfleration vectors.

  When an object experiences uniform circular motion,)id ebpqs*m0 md,:ml3 the direction of the acceleration :*3pmmd 0,b) s miledqis

  Consider a particle movin0e9k 8cxn q8tng with constant speed such that its acceleration of constant magnitude is always perpendicular to its velo k08ntexc 89qncity.

  What type of acceleration does an object moving with constant speed i m-f0wad9i ; ysg7lf:- vtd+cpn a circular path experien lctmvfag-fp; +: 9s-iw7ydd 0ce?

  What force is needed to make an object move in a circ.lz)94 trg 9owvn5ckuy0*jma le?

  When an object experiences unxsvli 2 x8ix0-iform circular motion, the direction of the net force x xv8s2lx0-ii is

  A roller coaster car is on a track that forms a circular loop in the ; 0 fc2 tlnv5*mhij,q3paore,vertical pl*alfh;i 3vtnq5,2rp,j 0o mecane. 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 rzcd+wtgrjn64a0 ; i/e k7*r wa circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the trjr+0nz/c47k*6e i rwd at;rwgack 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 ,4-8qsr,opwr q geqr/a semi-circular arc until it is going straight up. Just as the p-rwe8 op,/qqgs q, rr4lane 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 curvs5 dl1*9 h6 p3/o4gn5ixljipo xp c))cx4 xjvhe of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a / .8x 9qdg,q+;ie(iul szw sehcurve of radius r at 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 around the curve for the second time, compar/ug;zq9x 8 hi+esewd,(. qslied to the first time?

  A car goes around a curve of radius r atawfc1(vcsjp/anc tyd+7,an3eo :4k7 a constant 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 cu:o, p 4a+j3a(tk7 wd7 c vsfn1aycenc/rve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speedlktu ) kp, a++k*qd2rd v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal copk)dk +rql ,atd+*k2umponent 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 angle, but ouhps5hlnu*jdb / 84l4zrxf0 , ne 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 the larglfd hz4ub jr0,8h4 5nl/ux p*ser radius curve?

  The banking angle in a turn on the Ol0+ gwn/x,nwm x7 l2kuuk-y cfy-k+vh3ympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb then0k -vcn+ux wm,u g7kl2/ whyx+f3y-k 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 to have ki sihoe a7 +37mpmg.0isd83sboth centripetal and tangential a a+78p3g so ii.m70seksd3imh cceleration?

  The gravitational force between two objects is pff2mqzd(u g /gd 6g.t dt9-2zx7 dlj1vroportional to

  The gravitational forc1wj7 acgu,w-ce between two objects is inversely proportional to

  Two objects attract each other gravitationally. - cfwt w,,a-;;:u+mb bnumzyfIf the distance between their centers is cut in half, zc+mba t-u;f y:,wb u nmwf,;-the gravitational force

  Two objects, with mav fn1:ast*i 1solq x,8sses $m_{1}$ 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 masse rf psz7 z4sh0go7-(ufew,s1vs $m_{1}$ 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 univers u50b2qdj3 z+sgc l4spzq *q.1twqy vod62v f-al gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moon i4nv j34eyr ((luaak4r s

  The acceleration of gravity on n8a1d9; ew *g1cdvzlqd(cmm4the Moon is one-sixth what it is on Earth. An object* ddl(qv 1mdc1agwe9 ;mcz8n4 of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fjj9) lp y+2 7cb/w fpmhxpy1o,rom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point isjerw-+sbtqx7hm 5 qvq 1(-6is it beyond the pull of Earth's gravitx(r+-hqbt wj5vq-sm71 iqe6s y?

  Suppose a satellite were orbiting the Earth just above q(xnx:+-j nit8gfyb -the surface. What is its centripetal acceleratioj ytx: x+b(n-8q nifg-n?

  A hypothetical planet has a mass of half t 61u(x/iteyxrtv* 0mwhat of the Earth and a radius of twice 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 x/r( iv01tw*yxute6m Earth?

  The acceleration of gravity on the Moon is one-s ox .9xn.a7(js1gpe 3d2s5k/arodsc41 hll ccixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What phcxk1c5lxcs/ 7doas l3 (dn1oj .aseg.2r 94 is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, b: m av/m+4er/nami skc,0(lot ut planet B has twice the radius of planet A. If planet A has mass m, what is octn/ e 4,a/+airs0 l:m vmk(mthe mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the x,m8 n,ag5a/iblq 71bnttkl4mass of planet k,ai5q4t b/lat1n7gxbm ,nl 8 A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (rad;h 6jdya qa:11djyaq *ius r) about a spherical planet (mass M). Which expression giq: hyj d;q*ya1d1a a6jves this satellite's orbital velocity?

  Satellite A has twice the mass of sates,y6bp 7yohkct4y0;i xb fe2)llite B, and rotates in the same orbit. Compare the two satelli ybexio)bhk7y p4s2, 0 ty;cf6te's speeds.

  A person is standing on a scale in an elevator acceleratitd8ud;x 7 eprs)jgf-57n/gwc.7e yi rng downward. Compare theuxd.5ne /gdpr 7)ig w8r;j7e-ys ct7f reading on the scale to the person's true weight.

  Who was the first person to realize that the planets move in /hnkq+( 2kb 61li7diy+ jgdnmelliptical paths around i+6hi2d/ knd+k l gqj y1m(n7bthe Sun?

  The speed of Halley's Comet, while traveling in its elliptical or) nm1ax;ifm+pu40yz lr -sk/fxc 2be+bit around the Sm-4c ekial;1f/n+0fx xb+ puy rmz)2sun,

  Let the average orbital wz(s 0lyuj2ew, kjo+ 2radius of a planet be R. Let the orbital period be T. What quanti2 u0e(yk l2jzo+wjws ,ty is constant for all planets orbiting the Sun?

  A planet is discovered to orbito:jz,-r c5rx ipp51st around a star in the galaxy Andromeda, with the same orbit trxsp5-,c1ij:z5por al 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 period?

  The average distance from the Earth to the Sun ku+ f nvtwzxw5rmy9.o;n; ,a,kg: 6sjis defined as one "astronomical unit" (AU). An asteroid orbits the Snn wva jfgs6, ykumx+w,;r:ok.t 59z;un in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.1) *kyjzi+ y (ea:;bnj ix-rah

  List the four fundamental forces in nat*a-*v.owd rn v:zk rjbl:*)huure.

  An object moves with a constant speed of 30 m/s on ,7 jsl;8mvqs jc* l*x9xj mo1ea circular track of radius 150 m. What is the acceleration of the ob9* ,78mql j;1ssmvlj xce* jxoject?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum:d )r6da9o nyna01cfz*ii p9b speed around a curve with twice the radius? (Assume all other * nni9 dr1z 9) :pobdfay6ca0ifactors remain unchanged.)

  What is the centripetal acceleration of a poin3arll o (;,qoct on the perimeter of a bicycle wheel of diameter 70 cm wheo ,3oqlc (;raln the bike is moving 8.0 m/s?

  A point on a wheel rotag jr7f48d+jp vting at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal accelerjr d4f8+vgj7 pation?

  How many revolutions per minute must a circular, rotating4 x5c:1rs ykzmaf; sd3wtsn+; space station of radius 1000 m rotate to produce an artifiz k:a1t;c3s5rw nxd ys+m;f4scial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.51z 0cxm*t6 po2:itlqh km/h. What is the cenxc0 61pz:*l oih mqtt2tripetal force on the motorcycle?

  A 0.50-kg mass is attached to qi 8+g,o lhatvj989y;q l(jiu the 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 maximum speed ol +,j(8iijtg ;qoha9u9 v8lyqf the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vev*a,fl z:s8e4yjeml2 rtical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weighmf :,e s 8ye4v2laj*zlt. The stone's speed at this point is given by

  A stone, of mass m, is attached to aog nxfje+;2 f 5z+3cow strong string and whirled in a vertical circle of radiuoj +3ew fofcn;+x5 zg2s 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 given by

  A jet plane flying 600 m/s experiences an acceleration of 4g whe8j+xru 38sqx i.p *bm; iotid1n pulling out of the dive. What is the radius of curvature of the loop in wh88q1i*dom iu3s j; rx i.+tpbxich the plane is flying?

  A pilot makes an outsidepf.z 4jpe 6529 i6lqy5nvemvo /0peoy vertical loop (in which the 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 onfl2e0 y4.zpm q5n ovjpe9vi6o p/6y5ee-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about d7 7 qgf wsg6eaf/-/ktseven times his weight. What is the minimum radius of curvature that a jet plane/kgf77/dg qasw -ft e6'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 rada-o l/t 0trwdt .)3ahxius horizontal curve with the tires on the verge of slipping. H)o/-tr h laa0xw3.dt tow 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.s ejet1q.o-*v The centripetal force provi.oeq jet1-vs*ded by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius mpc*qp7r3x s/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 r *pmc3x7qp/scar to make the turn?

  A car is moving with a constant speed v around a level curve. Tl.d8;tob2zy)y av+ ig-5fcinhe coefficient of friction between the tires and the road is 0.40. What is the minimum radius o+ t;dc2l.ay85)z f-yonv igib f the curve if the car is to stay on the road?

  What minimum banking ap q/4h9 4ruousngle is required for an Olympic bobsled to negotiate a 100-m radius t4rq9hup/us4 o urn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsll6x6,pbfhjw4iami8.- b s px /ed 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 ra1ml ag xmrt0j1w 6jn zp-s*0l:*er: addius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m n wcz2- +*oihto;rq ;lis 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 en m.fg1fky*/dsd of a string is revolving uniformly in a horizontal circle of radius 0.50fsmy/.*g k1df0
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 uniformc :inkdyd b re0jqcg.uk2.3/9 rate to a speed of 45 m/s in 15 s, 2edni r/jy 03u.bq: kdgc kc.9moving 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 mz: rni:: z(hd:ptoh.0vkzg 8jass $1.67 \times 10^{-27} \; kg$ 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 : o0p;ls-ppqg45*j, ygohebq70-kg person standing on the Earth, due to the Moon? The mass of the Moo,*q pgblyp:og sq0p; e -45ojhn is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractivzv i-.nk- u2iy u,:fshqg9we*e force between two masses is F. If the masses are moved to half of their initial distance, what is -q*ihyiu. 2: sfe 9v ungk,-zwthe gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance fro 7j*tdmf 3(ejqm the Earth will the gravitational forces due to the Sunte f7(3 mjdjq* 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 isn:)c o-orye1 10 mgdj)s x(wuw $7.4 \times 10^{22} \; kg$ 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 equal0 dl )/+3u(xvl(f dnrwwqvu1z to the radius of the Earth. x vnzd3lwu+ vl0ud((/qw )rf 1What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfach(pbo2p8+k (fd 3 reeke will the acceleration of 8 +hk f3(kepr2(pebodgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above itsc:0qm8 75euskd5h9j aksf8r a surface equal to 3 times the radius of Mard5qchau m0s8 5k es8f:ra7j 9ks. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000sl(n5. j tsoh- km from some planet's center, the acceleration of gravity is stn .(ljo- 5sh$32 \; m/s^2$. 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 Earthk2bbpk8rj rm+bzf53 q i+f;w0 has radius r. If the object is raise3ki jwb++5 8krz rfb bpm02;qfd to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 1hz m ;vjnz40t;00-kg person change when he goes from sea level to an altitude omz zjnv;0;4thf 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 z4exwsv)r kz0j 4*d x2Earth's surface. What i2 *z4z0er xsw kjxvd)4s the satellite's weight?

  A spherically symmetric planet h ,c3) t9evesi 6/2n4wknfchklas four times 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 tec 93/v2)in,fkwlh6e 4tk cs nhis planet?

  During a lunar eclipse, the Moon, Earth, and Sun all l w:7 cocagg*e;5jca4wt,yn5zie on the same line, with the Earth between the Moon:4z,cc*gw5j;naaec o5g 7 twy 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*klc(p 1 b6gyk 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 Eartmsymyhk0u (. 7h (i.e., it just skims the surface of the Earth). What is ty mmku7y0s.( hhe speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low tauhid:ev: *q ;4 0tgd15o isscircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution ti5:ds:qvo hgd;*40e1u s iataround 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 su t8b9nqdj(*f srface of the Earth. It is observed to have a period of 89 minfst (*j9n8bdq. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jup(ovk g uw,n( ;7-dcsxbiter, 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 orbits the planetbe/, kiw/)s6qlv1gx+cb gp,*+ d gp qu 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 nealn c xz:fb; q85nqpms3i)pfjg,q8p8 3rly circular orbits. Moon A has orbital radius r, and moon B has orbitalnf3gp np3xmf;qq bsp:i) 885j8lzc, q 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 ig+u wo;hb 6l .y1d9fyos $7.78 \times 10^{11} \; m$ 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. Wh+aeer8pzng*z,7sw f/7yk -d-g7 swjm at is the average distance from Jupiter to the Sun? (The distance from77sjd8rz /emf- pe,-+ k*7gwan zwyg s the Earth to the Sun is $1.5 \times 10^{11} \; m$.)