Is it possible for an object moving with a constant speed to accelervqat.z95 s/w 591r/xx bpfkpf d4r c:tate? Explairvqzfsx/rdt 9 bw f41atx9pp5:kc/ .5 n.

  Consider a particle moving with constant speed sr-7ie m(htyu u5)f8trrxv.,quch that its acceleration of constant magnitude is always pe8rf mx- 5yv7h qtu.r ,ri)(eturpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direcxpm01sh;p3vn9qly 4 mtion of the object's velocity and acceleration vx9 4p q0 p;l1hmy3mvsnectors.

  When an object experiences uniform circular motion, the direct7)r dn5o 5zoxbion of the acceleration id5xrn7 b5o o)zs

  Consider a particle moving with constant speed such that its acceleration of con;ookh 8oda fe,mlo*8 ;stant magnitude is always perpendicular fe8h;m ,o*o;oakol d 8to its velocity.

  What type of acceleration does an object2tg6 0ix5,hv w xmu9rv moving with constant speed in a circula xvri gxmv692u5h, 0wtr path experience?

  What force is needed to make an ob6w8a ad)pph cx5d59cu 8;vv jzject move in a circle?

  When an object experiences uniform circular motion, the direction ofy;9-4del m2 eclov-ws the net force9- 2-yeodcl meswv;l4 is

  A roller coaster car is on a track that b30r x/ajx2o pforms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top ofojr0x3 xa/ 2pb the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (o 8q 0)uvp kb;+ck-xx*h:iljqmass = M) is on a track that forms a circular 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 xu ok +x*;:q -bl)ih8qvc0kpjfor its speed at that point?

  A pilot executes a vertical dive theni 32c ndm7f9be follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, 2f397edi bc mnthe 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 curv spba ef;2cj,-e of 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 speey+mo-h,xd3x ,ahz; 1iuns z l(d v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the carudxoh3s;,ai,m z nhxy-1zl (+ as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radi)rjg7 1va(k acnbmz kz72q8u, us r at a constant speed v. Then it goes around a rz)7jc7bgq u2,nk(ma8zvka 1curve 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 banked curve of radiusmx46 g yxp5 6 qdrdv jggfe-hos,3f+-, r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of thejq -fr5ge 3fg+x, 4d p ,myxdgv6oh-s6 normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled rhuaj.nuga. :gg8r7j)atmi9 ,un are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on :9ajt gi. maj. u, 8gahr)ng7uthe 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 t,5cn,i0ju(iy0-mrfln r cqb1rack 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 th5rn00m l- (, qyfnibu1 ccij,re turn. Why do they do this?

  Is it possible for an object moving around a circular path ;iw ;)7dyarfg3 pmp)j7g2z *qzm bn7w to have both centripetal and tangential accelera7 z m *fn ggzd;732ymrw pw7)p)aj;iqbtion?

  The gravitational force between two lynap*hc5.. sobjects is proportional to

  The gravitational force between twos 7pj9t b*t2fkb *mm8dr*rp4 q objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance beid 4j m5cmebd,b87h 5nt 93upztween their centet,n3du7i 4zb 5mmhc j9pd8e b5rs is cut in half, the gravitational force

  Two objects, with massesf/1eci10t w j;(l/v abth:dbm $m_{1}$ 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 mak9lmz2vw (v3io9ah6 f jh/j3tsses $m_{1}$ 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 gravidf+g -fzo u8 eh:mr4rcl ,ljz;qgy,+-tation.

  Compared to its mass on the Earth, the mass of a:z,jt a9eq.vb ) g)/ebh:hwvddj4j0 an object on the Moon is

  The acceleration of gravity on the Moon is okspx v-8a3ot 3ne-sixth what it is on Earth. An objec3 px 8okt3asv-t of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's si9ro0 fj1(byg urface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the d 2p hp7cx8-m doicx3.pull of Eartphccdm73 8pi.o-x x2d h's gravity?

  Suppose a satellite were orbiting the Earth just above th*yly:quh,yp. e surface. What is its ceyqpy * lu:y.h,ntripetal acceleration?

  A hypothetical planet has a masp) 7 47agpt yokdrcirb).6, rms of half that 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 thkm,47yb) ctdrpgoirp7.6 )a re Earth?

  The acceleration of gravity zb5xz 6l)1t,v tkgu1k on the 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'k11 g,bzv 5)zuxklt 6ts mass compared to the Earth's?

  Two planets have the same surface gravity, 76ib ypt rv8:x ,nra,abut planet B has twice the radius of plan t,rnbi68a,:y7vrpx aet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the saml(mxjvk 4j,u5 e surface gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of plm5x(j, kjl uv4anet B?

  Consider a small satellite moving in a circ 6cx*wih h.ystwhvx):v7 ,e t-ular orbit (radius r) about a spherical planet (mass M). Whict).76 -t:w,hsxyxv vh* wihec h expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbity, id0 (hc5 :rkj7yncy. Compare the tw cy,r5y0jkh:( ic dn7yo satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Couw w.dcxyt 42(mpare the reading on tyt.2wu (4wcdxhe scale to the person's true weight.

  Who was the first person to realize th0p:x* . /,*cynvu: txviwyh0p:dcmso6m ;d sjat the planets move in elliptical paths around themj sncxd::h sm:x*6dw y*tu/ v;y0cop , pv0i. Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit aro *g7mknenqniu+f60.vdqh l7.und the Sv i6 h0+7nqkq.fu *g nneldm7.un,

  Let the average orbital radius of a planet be R. Let the orbitas2h ua9zni),h l period be T. Whaus9h2 hzi )n,at quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andrvuy 3a73+ l2hh67 2rrqq1jz jjv4flryomeda, 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 ne jy4+lyh3jl1q 7qj2rza 2u hvrf 3v76rw planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astron o6 jqk 1w.gezje /7wpe)v5(avomical unit" (AU). An asteroid orbits the Sun in one-third of a yegwwa57jekvv pq1/z( j6 o .e)ear. What is the asteroid's average distance from the Sun?

State Kepler's laws.z,kw9a gtxo(, d- -qeb

  List the four fundamental forces in naturfa i+/ra htosxgu *i- 2+,cs:ne.

  An object moves with a constant speed of 30 m/s on a circular im g:lehv)b-, track of radius 150 m. What is the aceig)- mvh,b l:celeration of the object?

  The maximum speed around a level curjzzxz4ak: 7cb 85z.reve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all o:7z4 e.b zrja 5czkxz8ther factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a biczm)fbvj h3-j;u b ;:piycle wheel of diameter 7;bf:u; p)b jz-mj3hiv 0 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00rcv64l8 )ib 5. um plub/i+rws rev/s is located 0.200 m from the axis. What is the ce.)ic m ll5ubv/6rs4iwpru+ 8 bntripetal acceleration?

  How many revolutions per minute must a circular, rotatin+ybe9nm5ftk at(y r6c)y3w7 gg space station of radius 1000 m69 57tek twyb)a+ncgr3y( y fm rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around ae *w m38xy pdjuiep7(u*6upj4 13.7 m radius turn at 96.5 km/h. What is the centrd 8 e4mpu6 (jyi7epxuuj3w*p*ipetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirl5js/e sup/9mv2feik ux31 *lted in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What i /fuil je*m2/tsx upv5e19s3ks 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 ci0 sraat;r/7z/s xm 9k 0,lihfkrcle of radius r. At the exact top of the path the tens kaxi/ zm9s /0l7trh0,;raskfion in 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 to a strong string and whirled in a vertiwdy s8ux8 3c+ef/rht)sln:c-cal circle of radius r. At the exact bottom of the path 8 hfyd8l-ts 3w)es /un xc:r+cthe 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 when pulling 5+q 2jc27b-jcb 2arhq co-scy-n d-fu out of the dive. What is the radius of curvature of the loop in which the plane icjbnrys 2jbq2-7chcc d q-f+ua 2o5--s flying?

  A pilot makes an outside verticalev t9-c:h, re xbbh5z0 loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing dc,x-e5 zve9brtbh 0:hown 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 his wvhy ml3m74w o7j c2e(bg5c6eh eight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speemc 26c hm3blvo7eh4j57wg( yed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires y2;aty* xr8fzfo r70von the verge of slipping. How fast can this car round a second curve of radius 320 m? (As0y*r;zov2trf y8 x7afsume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat cu6r4ss kcs2o7:rbd v9lrve of radius 50 m with a speed of 20 m/s. The centrb:s 4v rsol29dsrc76 kipetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of q x s- bwy*s:sde907nsradius 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 car to make the ts9-7 0:dss*nyx wqesburn?

  A car is moving with a constant speed v around a lev(cqi2y7r7 b.r r+wer kel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum ra cky(+.iqwr7rb 7e 2rrdius of the curve if the car is to stay on the road?

  What minimum banking angle is requ5u *e7a:ty nw ) s8(t4cdvgkay 5fm3zvired for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s zyg4fmd5: s7t)na (u *vtcykae5v8w3without skidding? (Ignore friction.)

  A horizontal curve o +sy3f r xy;p.0vm0bhyn a bobsled 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 ja gkugs):4.) mzz ib;an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is)b gvz-fgz;* so3 pvs1 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 a string is revolving uniformly in a horizonqb7htm4z (1 vhtal circ4ztv( hhqm 1b7le of radius 0.500
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 racv,7j .vmub+m 8ik eb9ye car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a cirv.8j9i7 +kvummbb y,ecular 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 consist y, lg:ulxqd.bg 4g w7ox.ic73s 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 :k gh mj:)0wxgperson standing on the Earth, due to the Moon? The mass of the Moon is : j:kwhmg x)0g$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force betwgj0z*vu/ox tm ai lve / -e4+1bmcy0m8v8n- rbeen two masses is F. If the masses are moved to half of their initial d a4 cgvjoyuz-x0lvb /t1-ee* 8r0mi/v nmb+m8istance, what is the gravitational attractive force?

  For a spacecraft going from the Earth ta9* o bpua7ts++( iprk cp/k)koward the Sun, at what distance from the Earth will the gravitational k r (/+su*ia9)oka7pbp +tkpcforces 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 Moon .gnhzt ymaw4;+x,,8ngquj 6cgn7 , bwis $7.4 \times 10^{22} \; kg$ 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 :s rsq,38 7lnk twjn+q6;q djydistance above the Earth equal to the radius of the Earth. What is heqjr,nqwld:8;kj3n+ s7ytq6s r acceleration due to gravity?

  The radius of the Earth is R. Ak3 lvzfwb,7-:)hge/g(jv qf f t what distance above the Earth's surface will the acceleration of gravity7e fjv )(wk-qhg/f:bv lz,g3f be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equ hq5 )5k.sb;iugkvqxdk6m8c0al to 3 times the radius of Mars. The ac qxb c0kk658duh5gqsv kmi );.celeration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km fromd7shyp lke8b 73+c wk7 some planet's center, the acceleration of gravity is w3+sdyp 7l e8kb77k ch$32 \; m/s^2$. 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 t4nj o 5f6lnzi aiy568dhe Earth. The Earth has radius r. If the object is raised to a heigi 6oj df n4lz6aiy585nht of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes from dt3m6,t l)nlc4wz q hzoes 9*;sea lev ,s4nzc zmwq63)to dlt;l*h 9eel 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 mas*c9 9dfu9qewf) btioo)y uh77s 100 kg is at a point 3r above the Earth's surface. What is the sath y 7f 9odwbeuqtoi7*u99))fcellite's weight?

  A spherically symmetric planet has four times the Evce:0ky2d j:karth's mass and twice its radius. If a jar okdc 2k e0jyv::f 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 sa nu-eue k4;v9rme line, with th;4ueenu9vr -ke Earth between 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 he7gdw(c ;;47ur u jnvis 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 Earth (i.e., it just s*5i,adk3qvn* tijsa 4 ;x5tpjkims the surface of the Earth). What is the speed of the satelli v*xtiaapqtkjs*5 jdn 3;,5i4te? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth ( *loz/ljrif1 /ts 2kjd7a9o6 ji.e., it just skims the surface of the Earth).j9a o fors/6tjz2l7*l/k1idj 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 230w5swe 1)/n vqu km above the surface of the Earth. It is observed to have a per/u)5ws 1ew qnviod of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, ha8mqx3yd87 o qas 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 Jupite-85 qmplzttu*0lpy ql3h 94m rr orbits 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 .p)nf0hupwslv66 a4x( ho.xn0; yhm xin nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A take wp00oh a)s6 ;(vn.x4fxmnhlhx6 .puys 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ik,;5qvai qibl.a3; xts $7.78 \times 10^{11} \; m$ 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 is the 8gf jdwm-:k7gzm5+su average distance from Jupiter to the Sun? (The dist8gj +sk -7 5ufmzmd:gwance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)