Is it possible for an object moving with a constant speed to accelerate? d+ 8f+lcoyk wy-0tc6j4cqt4 )p4rs kz Explai k+ctsl )6+k4d4j4ccf rw0oqz -yt p8yn.

  Consider a particle mm9 xez,d (hggkhke5:5a 0xt* joving with constant speed such that its acceleration of constant magnitude is al kgzt m,0hj5*:xakhe gdx5(9 eways perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Comp0 + m*mmp9,nf8nmmqbg are the direction of themmq9f,b gmnn*m pm 0+8 object's velocity and acceleration vectors.

  When an object experiences uniform cir 2c /s p99arqm*z8iaubcular motion, the direction of the acceleration iu*/9zcr2 biam8 9qsp as

  Consider a particle moving with constant speed such that its aoyc3 4.sp5p bjb+pbz hf0)t-occeleration of constant magnitude is always perpendicular to y 4oj.zb hbfp)o+-0c3ppsb 5tits velocity.

  What type of accelerat83,vgycfdxz +nv/bc6ftu;1 y ion does an object moving with constant speed in a circular pathvfu+ g;8f b,t yc 3nc1vz/6xdy experience?

  What force is needed to make an object move hf+jnf xznid;5wa 3,0in a circle?

  When an object experiences uniform circular motion, the direction ofbd./ axei42 zt the net force is2txiz/4 dbea.

  A roller coaster car is on a track that forms a circular loop in t-gpec k4 dmq.n,s6pm,nf* bv*he vertical plane. If the car is to just maintain contact with track at the top of the loop, what mqfn e,p cpb s**-,ng mvk64d.is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a aex y ;q*r/ve.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 for its speed at that point?q;ra.e* vxy e/

  A pilot executes a vertical dive xhudr ( )n1i m4mi)u7rthen follows a semi-circular arc until it is going straight up. Just as the plane is at its lowes im))xi7 41m rrnduhu(t 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 w7 6j3c+kw y(/e.( u9tdgyy/zb7zgis dv.tk wcurve 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 ra zor/d 3je99hc+vv*drdius 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 cao9* v+zrhdv jd/r3c9er as it goes around the curve for the second time, compared to the first time?

  A car goes around a cur6d6fuey d*:4jb adj 7kve of radius r at 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 b7 uf6:adde6k*y jd4jgoes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. ob xn0 0241 hcx.lcazh If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal compone4 0ccz1nx 2lhboa.0 xhnt 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 onq3 s ocai- )ny;b8-ctle has twice the)y3o qc8bc-ti; l- sna 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 larger radius curve?

  The banking angle in a turn on e 3ei-f-m jkn3the Olympic bobsled track is not constant, but increases upward from the horizontal. Comiekf ij-3m 3e-nng around a turn, the bobsled team will intentionally "climb the 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 ha1ys n6:v n6s/mo4+eh 3ylo.c*y 1mxiufnvr 5uve both centripetal and tangential accelerati/cmf.iv4 yn 1ehyn *l no 5+s61ur36:v osyxumon?

  The gravitational force between two obji6q5iac9r85f.qjug6nb ( t. vmpypo5ects is proportional to

  The gravitational force between two objects is inversely prop/wrqgx jb68z. ortional to

  Two objects attract each jjmykan2 3)3kg/q 5sdother gravitationally. If the distance between their centers is cut in3d2 jjs )5mqykn3k/ga half, the gravitational force

  Two objects, with massev p.l4 s-4amv4srk 7ras $m_{1}$ 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 man8gwosah, e *o,(;quxsses $m_{1}$ 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 gravitbl;dw wod+p o+ a0-(ikof82st ation.

  Compared to its mass on the Earth, the mass of p0iws) 5:sudman object on the Moon is

  The acceleration of gravity on th(zuhqxeg q:i,*0nmol sg m(;-e Moon is one-sixth what it is on Earth. An object;gqh *s,mi 0u:ng oe-qz(ml(x of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'a4;us,lwy1 erb6d ;k se3.co ws surface, the rocket's weight

  A spaceship is traveling to the Moo4( r33exiuytn n. At what point is it beyond the pull of Earth's gravitxi 3u(4e3yntr y?

  Suppose a satellite were orbiting the Earth just above the surface. jan e/t7a2)oi What is itsno2/)a jeati7 centripetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius :yh8wyy 9o2uir vc9u+ of twice that of the Earth. What is the acceleration due to gravity on the plhy io u9y+r8 29y:wcuvanet 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 otrweth-3n. agr u1w:.n Earth. The radius of the Moon is nte.hrr-g w3t:w a1 .uone-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravitrx* crw4x v gbo0oqi. l01f6.apz:y*xy, but planet B has twice the radius of planet A. If planetygc6 0fxz ob i0.: 1* 4va*olqxr.prwx A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice t)m*wk1h*qz)zbuxi p/ l *tv )khe mass of planet A. If planet A has u)) *q m ptz)k1*vi*kwzbhxl /radius r, what is the radius of planet B?

  Consider a small sat22 p o 3b() 0 *em4,tozor4rejnqe*oqr3rltluellite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression give qonolqt*,rj3r uop)ee* 0l3(2 rbz42mo4 rtes this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the samw7(rcrg 4d e*ee orbit. Compare the two s*ewg ( dc4rr7eatellite's speeds.

  A person is standing on a sca3a)s :hs0ox,; w1a lej2o abyvle in an elevator accelerating downward. Compare the swa,h o0s) ao2va3b1x:l;e jy reading on the scale to the person's true weight.

  Who was the first person to realize that the planetsxenr9 10s0hq:lse sq 6 move in elliptical paths aron sql1:0 s0xr6eqesh9 und the Sun?

  The speed of Halley's Comet, while tauynqtl4* :: kraveling in its elliptical orbit around the Sun:nya :4ul qt*k,

  Let the average orbital radius of a planet be R. Let the orbital period be T. :/stmzd k 01dx What quantity is constant for all planets orbiting the Sun1s/ dmxk: 0tzd?

  A planet is discovered to orbit around a star in thqng b,*x7yyhf,c a3ws +ow9-j e 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 revol9c *yf-hbw 7w,o+a,s3j g nyxqution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "awue 8nche1;2qstronomical unit" (AU). An asteroid orbits the Sun in one-thi8 eew cnqu21;hrd of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws./7t1 d9zz-ghklzeof *

  List the four fundamental forh*g c c5;wys.vnb/1n eces in nature.

  An object moves with a constantxdwws+qe 8 bx .;z(b.hw;j6 g;dlq/w j speed of 30 m/s on a circular track of radius 150 m. What is the acceleweqw sd( bjdj+..z6w /q;gbhx;wx8;l ration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is th7k/a :xxom f/ge maximum speed around a curve with twice the radius? (Assume all other factors remain unfk x/m7o:/ga xchanged.)

  What is the centripetal acceleration of a poinf;agd-c( uwt2t on the perimeter of a bicycle wheel of dg(fw cau-2t; diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0fd s(7 si5:.9a*k8rre tz1u+o kbcblh .200 m from the axis. What is the centri e9ri(skfob*5:kh ubazc .8rts7 dl1+petal acceleration?

  How many revolutions per minute must a circular, rotating space station kiwz71 o2)rd sof radius 1000 mw17)zks odr2i rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 sl.gr31x 2- tc0,s:c l3ynna tr ort/nm radius turn at 96.5 km/h. What is the: tc.cnlxlr2/ ynns-t a,t o s1r3r03g centripetal force on the motorcycle?

  A 0.50-kg mass is att-5u g.fi uj9c b3,4iv3mmhxkpached to 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 withstuifuh 59mjpc3v4g3ik., x -bm and 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 veribgytlpjzc 74p 10s +7tical circle of radius r. At the exact top of the path the tension in the strizl7tp 1y7p+i0jsg4 cbng 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 strong6s1cl exjp1+apge)s / string and whirled in a vertical circle of radius r. At the exact)psej1ap6gel x +1/ cs 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 when pulling out6rp0rrhxxe d6y;1a2 i of the dive. What is the radius of curvature of the loop in which the pae 1rh6 rpr0iy2xd;x6 lane is flying?

  A pilot makes an outside vertical loop (in which the cen,arh+ sxg02 kpter 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 one-half of his normal 0xg+hkaprs2,weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What n b65rsywmf2:-i 9y2kxkg 3xz is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can ms6zfx :93y wxi-rk2n2 5kybg tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds iw +(:6dd+nf 2v:e uqix3yigr an 80-m radius 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 su6+wi iqd3(ur+y v2:f gixd :enrface.)

  A car is negotiating a flat curve ofgr75/8 ez glrr radius 50 m with a speed of 20 m/s. The centripetal force provided by frictr57lgr 8/egzr ion 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 az f*. pmnxrp53 speed of 14 m/s. What must be the minimun.z3 rpx5mf*p m 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. 0r .q ,fvf z6uyep9qq2The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on thrfe.qz9uf y0qq, 2v6p e road?

  What minimum banking angle is requi5ixc(:ulv -rom1duqq- vp 7 8mred for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignor:q um(l8voqud1 7- icpmx 5-vre friction.)

  A horizontal curve on a bobsled run is bankhv01g qobhd+:b+ fw/ a-b8qsted 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 anghky3at:wwy: 8 o,x3xc le of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is,ogiaik/ pa (dy4(4uf 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 i*jr.zs72 vyf kn a horizontal circle of radius 0.500 y2sz *.7kvjr f
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 u4 3ijk(rl v5wgniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500w( kl5 j3g4irv 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 consis) kup0e*cckf) ts 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 gje+b*rhe oe3+h,lk/force on a 70-kg person standing on the Earth, due to the Moon? The mass of tjh *blo+rke 3e+e ,hg/he 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 bss;8r7bz0e;iniil x +etween two masses is F. If the masses are moved to half of their initial distanc elzs+ rii8x;b;0ins7e, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from ial gghfck 8y69b; ah q,)6fttg,)p4uthe Earth will the gravitational forces due to thepti8y,6at)) bggqc;gu k4,h ah96ffl 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 imb v(3hbz:np3iwd -lby5)2c) e+ns fis $7.4 \times 10^{22} \; kg$ 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 ther .9 i, whgfg;m7ny z,3vatanl2f1.de Earth equal to the radius of the Earth. What is her acceleration due to gravimzg f7., 3ahy,nv 2. taer;gwdf nli91ty?

  The radius of the Earth is R. At what dix jjc1p9. 3uws0o8ub u,(depbstance above the Earth's surface will the acceleration ofj d pubs(c u0wox8u9b,13jp .e gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equo9a8xs h+pg54osnj0tal to 3 times the radius of Mars. The acceleration ofo5ssjhn+a0xgp 8t4o9 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 vpyhr2z4 nkla ue+3- 7of gravity is y4l+z -vu3a7ek hnr 2p$32 \; m/s^2$. 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 Ew;q3.nqauxc17i )kbw arth has radius r. If the object is raised to a height of 3r above wnwux ) qa i.q1c37kb;the Earth's surface, what is its weight?

  By how many newtons does the weight of a 103f3p7gyfqyqm . e7m bt*ae*5 jm3md w70-kg person change when he goes from sea level to an aljg3mdymf7 qa5.m7p m7* wb3etey*3qf titude 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 n 9hlq9iocz-/spss+3 100 kg is at a point 3r above the Earth's surface. What is thzcnss3qh/is 9-+ plo9e satellite's weight?

  A spherically symmetric planet has four times th:: q cux4mv ( r;pzljwvsn:v*f:dzj:7e Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on mjwz *: vvrvsfu(:x:l p:jz 4; q:7dncthe surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Mo suclz5y,ppk w;;ei8 1on, Earth, and Sun all lie on the same line, with the Earth between the Moon5p;w8c zi1sl e;yk,up 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 the Moon p+nia+v04hzo0agjw +)rnj1y.
(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 circuk w7id 6kea-- mb,)cj:j7pevolar orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean raep e7 v-7 m)ckkj:ow ibd-j6a,dius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cir3g(a- a/kabe/ h)vio 1*6+bocs dcxygcular orbit about the Earth (i.e., it just skims the surface of the Earth). c)/ig/ ov c-oxy*ae s3ah1kbgda(6+bHow 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 230 km above the surface ofju 5j 3nj0cm*t the Earth. It is observed to have a period of 89 min. ju*5 3njtjm0c 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, has a6dz)/j k12;j2k gsk2l bm vprin 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 wia i:l81+s2-bp 1(sye;sa ksqymvqip) th 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.o( hfx hyw3r*- Moon A has orbital radius r, and moon B has orbital radius 4r. Moo-yo(rx3 whf*h n A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isfs giu3f is 94+d;ezip4q ,wh) $7.78 \times 10^{11} \; m$ 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 ave2fkompm p:3 kt wbi3gyf c3(4,rage distance from Jupiter to the Sun? (The distance from the Earp ft mc yio2p,(fkk3m34gw:3bth to the Sun is $1.5 \times 10^{11} \; m$.)