Is it possible for an object moving wi948cfo2e w hdew*d;wdth a constant speed to accelerate? Explain.wfe2dcwo84 dw* he d9;

  Consider a particle moving with constant speed sbd g pn(jka+0)uch that its acceleration of constant magnitude is always perpendicular to its velo (+kjand0)gbpcity.

  An object moves in a chagktp*qti l48b1l oh78o2 m/ircular path at a constant speed. Compare the direction of the ob 8hlgb hook 7tai4t1/l8 2*mpqject's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accuo :n.jiv7v58i j;nrbeleraun7.58o bvjnjir:vi ;tion is

  Consider a particle moving with constant speed suchfp 8ll:xlg5(2xevvcvm1 /oskwi k1 ,) that its acceleration of constant magnituo ,p wc/:kmg518ki ll( 2evslv1vx)xfde is always perpendicular to its velocity.

  What type of accelerati3 ,gpm+ dq4azkon does an object moving with constant speed in a circular path e4,+p3qk zdgmaxperience?

  What force is needed to make an object move in a circl7kbq ;:mydv7x+ 2kxtne?

  When an object experiences uniform circular motion, theh s05 jpyr9c6,yg 8ifh direction of the net forcep yi hf, 60cs59yghjr8 is

  A roller coaster car is on a track that fo*flwmd ewa,b4kj73 b k; -x9zvrms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minkwf ,jbd9z4 kmxl; bv-*3wa7eimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (e q 7 ia.kakfa *way)w,,/so(rradius = r) in the vertical plane. If the car is to just maintain contact with the traia7q)a./ yws f ,,k(a*kowear ck 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 unt,-epdd6skkj9x,i (w xil it is going straight up. Just as the plane is at its lowest point, the force on him k ( dw9,i esxj-k,6dxpis

  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 raayog/2k5if1xr/d 0je dius $r$ 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 v. Then c168 : xko27nucz(ed2 qlqazilwe1t3 it goes around the same curve at half of the original speed. What is the centripetal force on the carel2:26c3dn8wi zlqto 7ec uaz1 x1 (kq as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. T x():uwp sj0meb*p2achen it goes aroundacpp(x)jbm *w e :0u2s 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 first?

  A car of mass m goes around a bank bmtee5b .jm296ec- vp,blwr 0ed curve 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 ,w-v bem e62p0 m5eblb .rtc9jfrom the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one hn0vh,eua *+i 9ek0oh,qvg ma 7as twice the radius of the other. The safe speed (no friction needed to stay on thqkai0h*9 mone v+ vug eh,,0a7e 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 trackh1wn4b90:s;v 6qufblxsyw * o is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower cos 1* :suvb9lf0hno;qb4 wyw6xming out of the turn. Why do they do this?

  Is it possible for an object moving around a sk3 9r1kco 9atcircular path to have both centripetal and tangential acceleration tok3ks991arc?

  The gravitational force between two objects is proportional t/34ux ;jv,jmizg fv.hvk 1y *e4hr2yto

  The gravitational force between two objects is inversely proporty48 19 sl 8;qoiulhfkw q8kpvnn;r/bfh z9g *)ional to

  Two objects attract each other gravitationally. If th :t3,xma e uro1dhm zye)4t/;oe distance between their centers is cuy3 :r4aee ,o tom1 thzu;x)md/t in half, the gravitational force

  Two objects, with masses 8 tlnhqnss,w3(c y7ej j; k/:b$m_{1}$ 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 mass:20xj deppcl( 9s(mjyes $m_{1}$ 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 gra5i9tn( vv:4 yh;src5s bius5 jvitation.

  Compared to its mass o;qons+d;jnt 6n the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is op6 5kuk*p* 3m c4t2zv ,jx pat8wdjce4ne-sixth what it is on Earth. An object op m4j,82 xtk5 w3zuk4dpapvc6te**j cf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surf ;ga-yfd6 2a+yg-s, 8eyjmrv ;nfx 5myace, the rocket's weight

  A spaceship is traveling ue cvq ulk(+h1h8 h80qto the Moon. At what point is it beyond the pull of Eartl8kqqe1c0 v h(8+uhhuh's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Whai71jjr, gocko5 ,on/ut is its centripor/5n1 co o, ,gikujj7etal acceleration?

  A hypothetical planet has a mass of half that of the Eton dtf1nfu6 ( xc.afe1n:t*.arth and a radius of twice thatttuo 6*ex:n1dfcn 1.nf (a.f t 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 one-sixth what it is ht8+5yb lo. qkon Earth. The radius of the Moon 5+tqbky8 .olhis 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 the radius of uw33tcnm o+ )g,yxga 2planet A. If planet A has u2tay) 3oggnc+mw 3,xmass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twicet(e e8ry6yan l9p. p+r the mass of planet A. If planet A has radius r, what is the radius of plr.eytp y+( 9a enr8p6lanet B?

  Consider a small satellite moving in a circular orbit (radius r) about a spheriwc.yv(wr rre,4mb5, qfuz)t 6cal .mc,rr)eyvb 5 qtzur(wfw ,46 planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rota*wz, b3lk2mfq, x 0ypntes in the same orbit. Compare the two satellite's spe3 zfpkn*byqw,, x02m leds.

  A person is standing on a scale in an elevatujidz7j j8k 8y.jk6,qor accelerating downward. Compare the reading jz 7j6,8.id8jjqyku kon the scale to the person's true weight.

  Who was the first person to realize that the planets move in ellipticaloko16h4nw2e9h,ixfny- eu .m 7,spmp paths around7uwhefx21p-.9,ne n km6y ,ispmho4o the Sun?

  The speed of Halley's Comet, while traveli y6z/ v2wbffxt ,l1n xy0/8wncng in its elliptical orbit around the f lxfy2y ctz/nw0x6 ,v/n18 bwSun,

  Let the average orbital radius of a planet be R. Let the orbital period be T.gw3g cb73ej xt5x;h clqle -.+2f gq4f What quantity is constae35 f42b ;-qjexlgf xqlg hwt.g3+cc7 nt for all planets orbiting the Sun?

  A planet is discovered to orb i;efncf/chm cn n 27yr.zx,6.it 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 wy2,cz.f6chen r/;f nnmcix . 7ill the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth/8a); k ewnimd3 jp7hv to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the wek)m3hjn8iv; p/ 7daSun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.vty5 vy,j0( do, cs;du

  List the four fundamental forces i, u*f9pbhl ax 0.d,frhn nature.

  An object moves with a constant speed of 30 m/s on a circular track of radi hrjv+ -cub(9-dajo hwf3*wz3jz0rc0ovf2a 6 us 150 m. w+*fcvr3v(ocj6j3 0jhz0 u ro f9 wad2bh-az-What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximufgi :6r6ez0xz m speed around a curve with twice the radius? (Assume all other factors remain zx: i r06ezfg6unchanged.)

  What is the centripetal acceleration of(a0cerq44tm jpq,vn * a point on the perimeter of a bicycle wheelp q, cmjq*tvne4(4a0r of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s i+r(g 8vvkoan 5s located 0.200 m from the axis. What is the centrg (rv5a+v ko8nipetal acceleration?

  How many revolutions per minute must a circu g bds(;lodi /0xgwm94lar, rotating space station of radius 1000 m rotate to produce an artificial(dg 40wig9 x mdl;bs/o gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a:vcax3oycfyd- g(i)p (o--a n 13.7 m radius turn at 96.5 km/h. What is the centripetal force on thn-:g-(a dcci y3 x)vo-fa( oype motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is f8m0mv0fd(rj q im;;a+4(ilg 2knpuw whirled in a horizontal circular path. If the maximum tension that the stringkf4nm( ;;i(0wmvda0u2+ ijmq8 rflgp 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 whirled in a vertical cir zxx,oypjsynxh z-e57e /3e u*3*l,m zcle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stone'z5y3*jxzo, e*hene7 xpx zmlu,/y s3-s speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical cir-e mtz:bwr 6k9dz)d.qcle 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-9re)zqzw .dt6b d km: at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when p(xzj9m0(hb9x n myoi2 ulling out of the dive. What is the radius of 99(xn y mhobz2(jix0m curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is bepze1k(a6 j) adm0w sol7(e2 ,q: xgrn xxc3ir;neath him) of radius 3200 m. At the top of his loop he is pushing down on his seipk 6on:(xr m(2wx ;x31 ),aedze0ls rqg7ajcat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seveij(h;-ra.iihug1s9 y cy e: i1n times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a verte h.uicayrh s i:(1yjgi;1- 9iical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radiu8 chq 8qbm0akf(:u4jys horizontal curve with the tires on the verge of slipping. How fast can this car roundyu 4f8 m8jk:ch bq(qa0 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. The 5 wr)*, (:toqhc+a hnqqgsua1centripetal force provided by fqc :ws)h*5+qr1(t nuo g,aah qriction 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 mustl0l *aol4 9ssp be the minimum coefficient of 0ls psao94l l*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 sava79w6o2 ix1pm )re coefficient of frictpo7ar m6s9v2)ixe1awion 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 required l6 m vu7f)xl/8jmb9f efor an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Im)xl jvebu7/f8 ml6f9gnore friction.)

  A horizontal curve on a bobsle2dyyu6x6:f )nh bfm5n d 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, ban vig +xeh*2xdpj)xeyw53 r5 j+ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banp, wxj 7hvm+u18tc cm,ked 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 the2qb;nt5ih5i pckr.g)e+pwj) eec 6: u end of a string is revolving uniformly in a horizontal circle of radius 0.500cq 2 wee;b:6 +u pr)5 jknit)hi.5gecp
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 ca9c cb4olb/ok7t/jv n6 r accelerates at a uniform rate to a speed of 4vo 6c/lk7/tb4nj b9 co5 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 consg6;tq 0ezz,*8 dvh+ hqwxg- mtists 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 onhp 4)*sxe-;t xw*uul x the Earth, due to the Moon? The mass of the Moon is w e;xps4 * l*t-uxxu)h$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between d0 fg13d+bbyak3btj93g5f zve)f 0ha two masses is F. If the masses are moved to half of their initial distance, what fd k gbgfe0a5+ yhb)v3b03d 3 zf9ta1jis the gravitational attractive force?

  For a spacecraft going from thecqrs n0ifzf yh)f -yg))pe,;( Earth toward the Sun, at what distance from the Earth will the gravitational forces due to thpy,)fn) f )s0yq(rf z-ce;ighe 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 ddaxw c03v, 8euu*d8jz5 2 uaris $7.4 \times 10^{22} \; kg$ 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 )uc 9wf6b7rhy a distance above the Earth equal to the radius of the Earth. What is her acceleration due to 6bw9 y) fch7urgravity?

  The radius of the Earth is R. At what distance abo, 1zsv5iq) yutve the Earth's surface will the accelersvu5q) 1y, tization of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abovqj8ucjh/l-;y7*r e a .g4zqnl e its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as comparnz* /j -4heq87cljr; l.qg yuaed to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km frn b:xa09so-rypb xdc (.m;;dtom some planet's center, the acceleration of gravity i .d0;cornbx(-xb: y9;tmdps a s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the dcsh)m0z3w*esurface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is 3*smc)dw ez0h its weight?

  By how many newtons does the weight of a 100-kg personms+e7pvbuc ;z: m 4-y*2ydx aq change when he goes from sea level to an altitude of 5000 m?u bmp aqs-y2 y mx+;vd7z:*e4c (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. w ro+cv). 6iwfA satellite of mass 100 kg is at a point 3r above the Earth's surfa+f.i6wv)o wrc ce. What is the satellite's weight?

  A spherically symmetric planet has fou( xjo0ly.8fyxr times the Earth's mass and twice its radius. If a ja lox.jxfyy8(0r 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 lie on the same line, withsz f*u2lyt2ry-w3 de 9s+vx i7 the Earth between the Moon and the yrd yx2sz 9 *e-uv+t273i fslwSun. 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 transport(cr)pc5axv3 )h rnk3 +ksg*sf ed 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 Ees 1l+tbm/;im d-jys 8arth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth is jm1+d/tm e b8s l;y-si$6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular o3y )zpl b8n+carbit about the Earth (i.e., it just skims the surface)aczb3 +l8ny p of the Earth). How 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 2hx.ce;b1 - b kkr9us.c30 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the E-su.cxke9brb c k;1 h.arth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter,4gj ag; g1,:wys3d 9opg0cize 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 planet with a cwqovh d+1bd*c 5*3adradius 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 jok ,ta+kh+e (circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes ak+ke(, to+jh 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i0w7/ :hlcnv1l* efy cys $7.78 \times 10^{11} \; m$ 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 Suz5zddkn a+v/b870yx -pnml-nn once. What is the average distance from Jupiter tz nd+v8z5/-a byn nd -0lmpxk7o the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)