Is it possible for an object moving with+jc+()cq e rsv a constant speed to accelerate? Explaie+ cqv +j)cs(rn.

  Consider a particle moving with constant specc 0 0jyo:id8ked such that its acceleration of constant magnitude is always perpj8od:c0k 0 icyendicular to its velocity.

  An object moves in a x-3,-h2m tv8ubalemw,.lavhcircular path at a constant speed. Compare the direction of the object's velocity and acceleration vecth.2wvv- ut l,-,x8aam 3m ehblors.

  When an object experien o1)h(hly:s mt -aqg02 ohj:nzces uniform circular motion, the direction of the acceleration i2t j1gasnzoq)-h(o:y:lm0h h s

  Consider a particle moving with constant speed such : o yed*/,3ktevu3+jisdp (bpthat its acceleration of constant magnitude is always perpendicular to its 33i e+u,y epd/dj(sk op*vt:bvelocity.

  What type of acceleration does an object movingh-as19pnqv;yki,k f k,w0,nb with constant speed in a circulaks;b-p awi f0h9k,q,n n,ky1v r path experience?

  What force is needed to make an object move in a circ5+0jk4cyne -v4 rhkpiso3ky , le?

  When an object experiences uniform circular motion, the directsnrjy )yuy ,yw,5;m(y ion of the net forcym) uj 5nyyw ,(yy,;sre is

  A roller coaster car is on a track tpw.rnnt+ grn le/ 3c,4hat forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top o3/ cw.ntrr gln +,pe4nf the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) ih(e51kn -glg ls 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 minl( le-g kn5g1himum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until i*zt. w :0v hda.qtzuv-ld6,q st is going straight up. Just as lszt,d0.*vd 6 qvh-awu:qz .tthe plane 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 cur()w4 e*kmws , aftt4mive 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 s*6x(xg afbcw9peed 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 a 9gxbx( c6*wfcurve for the second time, compared to the first time?

  A car goes around a curvew ,9x-5c pjius of radius r at a constant speed v. Then it goes around a curve of r x5s9w, -iupcjadius 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 ae:*ij uk: dgc:vh/.cb banked 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 from the road is equ:u cghvb/i* .ejk:c:dal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but dea un2a9m5pbd;h9 ,hone has twice the radius of the other. ,bdua5he9anm;hd 2p 9 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 the Olympic bobsled track is not constant, but-( qt-tpetcriwz)e 5t:1h g5h increases upward from e: rit 1gtqp)h5c(tth zw- 5-ethe horizontal. Coming 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 cvnp6)il o 2r s0-5ssr;cfc)cuircular path to have both centripetal ands2 )so0in;vpfr- 6lc)cc5u rs tangential acceleration?

  The gravitational force between two obj 0,ftnq7f;c0kp +:xqp+mysp4h2t i,*dptmhg ects is proportional to

  The gravitational force between two objects is inversely proport1ye 6c18oxcmf+e sv 2iional to

  Two objects attract each other gr4do*6n ;1amazkc *jx. 82 e-fkusow gwavitationally. If the distance between their centers is cut.z x k 1meg* 8 *asdwwak46o-njf2c;uo in half, the gravitational force

  Two objects, with massex0q4 q ;:guhjtr 5ngk9s $m_{1}$ 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 ma e2(q2zklo ei)sses $m_{1}$ 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 o6oglo+ m*a sj4;ya+d)tkh-q if universal gravitation.

  Compared to its mass onvi b bmo lnok*uj54e( h3wj2nm7.1a 9y the Earth, the mass of an object on the Moon is

  The acceleration of gravity on t.h1 +zhs2si k (5 ndv3bd0s86xq jrizzhe Moon is one-sixth what it is on Earth. An objectdr+h68 0. (vzzj3qxisbi 1nhz52s kds of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away*bofdn-p 69ev* iq5u i from the Earth's surface, the rocket's weight

  A spaceship is trave ara7 si+ck.,mling to the Moon. At what point is it beyond the pull of Eartrma,ic+s7 .a kh's gravity?

  Suppose a satellite were orbiting the Earth just abovt mvjsakh*m3kf93m7y *8( 1fd2ajjxqe the surface. What is its c3dsm qa k (7hf8jk 39m**ymjj vtxa12fentripetal acceleration?

  A hypothetical planet hasjr)kworgs5t zl+ 44a8 a mass of half that of the Earth and a radius of twice that g5r+raol8 wskt )z4j 4of 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 onyux(bbnqfaj521+kt); 4 bei m Earth. The radius of the Moon is one-fourth that of the Ea5nukbbfq2a y )j1b(mxei+t 4;rth. What is the Moon's mass compared to the Earth's?

  Two planets have the same sur3i: d- e(+tuxmuuf h-a(ch4v fface gravity, but planet B has twice the radius of planet A. If planet A hasuc:vf fmu( hx (--tduaih+ 4e3 mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of n9xs1hjv.u*fz z .ah+ planet A. If planet A has radius r, what is the radius of pha x .sv *z91zju.f+hnlanet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sphhz02 qjrvv9p** * ;,q f ijvvkyht6x4nerical planet (mass M). Which expression gives this satellite's orbital,h*n49qvjkq2t; f rvy0vhi6*vjp x*z velocity?

  Satellite A has twice the mass of satellite B, and rotio1fea) /1d/ac- kbfuates in the same orbit. Compare the two satellite's speeaa-ud)f / fok1bce1/ids.

  A person is standing on a scal wqv6kprh0+ h7e in an elevator accelerating downward. Compare the reading on the scale to thew7v6p0 rqh+kh person's true weight.

  Who was the first person to realize that the planets:0xdn w8 *-jwfsx ea/p move in elliptical paths around the Sunwe -jdwxsnfpx */:80a?

  The speed of Halley's Coeyyh .g0 ++tftqq ra0;met, while traveling in its elliptical orbit around the Su0fe.;t 0hqy+q arty+g n,

  Let the average orbital radius of a planet 8hbf4; a 6gcdr5z fx,mohcj+*cp7 -s mbe R. Let the orbital period be T. What quantity is constant for ag m d7cf romcj 65hac-;fh+,x*s4p8zbll planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the hn oh,;ayg -oha ;f/,ksame 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 nea,h- /oyh fng ;;hok,aw planet be, compared to the Earth's orbital period?

  The average distance from the Earth toe*; cgvtx,7lp the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year.lcep ,xvgt;7* What is the asteroid's average distance from the Sun?

State Kepler's laws..iq jpyvn ;yj996tc3q

  List the four fundamental fohs20x )g ocl6upj4s/w -rqlf2rces in nature.

  An object moves with a constan(nltlmg )u,0:+o7em+0w1qur hq gfh et speed of 30 m/s on a circular track of radius 150 m. What is the acceleratione+qh0mt+10hq :fmuu (,w7grnl oe lg) of the object?

  The maximum speed around a level curve is 30.0 km/hx:r .fgy)kl 2i. What is the maximum speed around a curve with twice the radiuskix):g y2rf. l? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point cbs2+wor3 he(hktgqj 1s/8o ) on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8 os8c(tr2)e+g/ wobhhkj3s1q .0 m/s?

  A point on a wheel rotating at 5.00 rev/s is lonypqevt.d1t +f52 .kmcated 0.200 m from the axis. What is the centripetal acce5qpn ktd+f te1y..m2vleration?

  How many revolutions per minute must a circular, rotating space /px a:yefy8;snm2dr5 station of radius 1000 m rotate to produce an artificya5ep8 n ;sd/y:rmxf2ial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mno tl5m+0 p *x f)pilded,,+cfass of 250 kg. It goes around a 13.7 m radius turn at 96.5 kfix,tmcf)elpd,*pn + 0d5 ol+m/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attac(vs lg*)rq0nwhed to the end of a 1.0-m string. The system is whirled in n rsl g0w*)(qva horizontal circular 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 to a strong string and whiugjs;n .y ;*qekdhy,+rled in a vertical circle of radius r. At the exact top of the path the tension id*+ys jny,g ek; uq.;hn 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 attak bll(v;km5:g.yl x 0e q+bfz/c4:upcched to a strong string and whirled 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. z cl(qce m/bu.;vlgyx +bfk: 4l5p0k: The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an accelerati,wfxp u5e5 ,f)fsq(vo on of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is 5)o5w p,e ,qsfvuf(xfflying?

  A pilot makes an outside vertical loop (in which the centey( el dujdh9)3; je(rmr 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 weig(3;j9hm jleu(yr ed) dht. How fast is he going?

  The maximum force a pilot can stand is about i-2yd;i p ls*.d)t txi;3ewimseven 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 ax3l;eswmitdi -y;ip) it2*d. speed of 250 m/s?

  A car traveling 20 m/7a v vce* zbkxepq):*;ayz+c ,xrl 8p,s rounds 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 sam+x, *yqvc*bx 7,e8)cvpepal ka:r;zz e coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of er5e m61p ty7anf,thti3 zev8i3-b5kradius 50 m with a speed of 20 m/s. The centt 8-y ,tnb7v1a563t5zrf i eeh3 eipkmripetal 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 rad k-mlsmqmc m*7 ji,./gius 50 m at a speed of 14 m/s. What must be the minimmc mm.j- lis*,g/ qk7mum 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 arou0m,5agstx s z4nd a level curve. The coefficient of friction between the tires and the road im x,0sgza5st 4s 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 3 llfvw4qwx.p8s(55 kv1n vky Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore fricti5kq4(lwwk 8vvp53 nxsfv1l.yon.)

  A horizontal curve on a bobsled run is *1slg c6x8(sde ad6n+ n-wlzxbanked 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 a9n)lqtb q/y9uu5ty / mn angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 ,th :977hhd swnp/v hfm is 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 horizontal cirt nh)0fsp5g b+yzta,y8s+) ( sc)chsjcle of radiuszj),nyh 0+at)bc p5y8chsss+( fst)g 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 race car accelerates at a u hh*e+ qls )7u2gne g+w,-iomrniform rate to a speed of 45 m/s in 15 s, moving +n2*+lw hme ) r-so ieu7,gqhgon 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 protowz8uqgu9 tanquo*e5nhf 1 k03 r l*/w)n 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 gravitation4cx poz)s g20rmrdu7(al force on a 70-kg person standing on the Earth, due to the Moon? The 0 grsmdz2o47c pxu)(rmass 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 forcer:p j/6v k8mmu between two masses is F. If the masses are moved to half of the ukp6:8j/rm vmir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance fromgo3,ob 8yo fl4pwmh .: the Earth will the gravitational :opo,3 myh 8ol4 bwf.gforces 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 ier uf,j )rcxwsoy:p1,-q 5c ;ks $7.4 \times 10^{22} \; kg$ 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 ab-4 vgv:fg t4tzove the Earth equal to the radivvgg4-tztf :4us of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At 4 v:ps 5fozp2-b8rz rw wug1w3what distance above the Earth's surface will the ag vrps8b wz4uo5 r12wz3-f:wpcceleration of gravity be $4.9 \; m/s^2$?

  A satellite encirclesn:q 2ifbz v ztvx4lnwg 9u:03, Mars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compare9:fizxg2b 4, qu n0wv:ln tzv3d to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceler:xx- ufsms6m 2cs8:bkation of gravity is8x ms-6xb:fs suc2:k m $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 c b+phbqiw8 p1ohvxyl 4p54(3p7asw. N on the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above h4xlp8po.cw7s bp 1hbp+3w aqi(v5y4 the Earth's surface, what is its weight?

  By how many newtons does the weight p* p1sihm;hi +of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of s1+*pmi phih; the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a poij2 j 61va xb 6qf1ae-abwhcl(4nt 3r above the Earth's surface. W1chvxwf6a 4q j2-l (6bba aej1hat is the satellite's weight?

  A spherically symmetric planet has four times the x5;p dxu20mbc 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 this pla;cp2b uxx5d 0mnet?

  During a lunar eclipse, the Moon, Earth, andhr46er . nsrn qe;()ku Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon he;n r6.( nqrs)r4ekuh as 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 q :brs:dn r)1wmhzz3k-hec xm:;)r 0kMoon.
(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 circfd2nusuib1 /; ular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the 1/f dbsi n2uu;speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low c7 ;ewbp uato: ayn(kgab pd;xpn-i1 ,0ki6 -j:ircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolut 6-1i(u n oawj7-aidappx,y k;n;btge:p:0 kbion 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 (q(br;1oopf-k 5e hcxsurface of the Earth. It is observed to have a perioo -5c b(1xqkh(rfep ;od 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, has an orbital dia;(yi ks64 v5j +eaazlameter 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 themr j:s3lb z65zx-n iu2qd+;tp 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 cip9mwqz s6 (y u;s3ey z6ynzs26rcular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How lon26zyp9(qw6nm3y6zye sszsu; g does it take moon B to complete an orbit?

  The planet Jupiter is u. pc;z;oj* un$7.78 \times 10^{11} \; m$ 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 os47yb3cm n.t znce. What is the average distance from Jupiter to the Sun? (The distance from. zc7my3t 4bns the Earth to the Sun is $1.5 \times 10^{11} \; m$.)