Is it possible for an object moving with a constant speerr9 lw6yx-+das6m n( jd to accelerate? Explairys n9ljd6+a -(w6xrm n.

  Consider a particle moving with constant spee.rdmn h/w;4*t,s a4 h8k saorld such that its acceleration of constant magnitude is always pehs;h4 rd8. /awna4rs lo,tk*m rpendicular to its velocity.

  An object moves in a circular pathmkk0kqu n53i5 at a constant speed. Compare the direction of the object's velocity u mn 0ki3k5kq5and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accb8ozz ua)s2xtfok n 0 i6*k93oeler0io t 9zo6nxusobz2f) kka 83*ation is

  Consider a particle moving with constant speed such that its acceleratip3 s8qub8v/: +jhlor d0kj yh2on of constant magnitude is alsk2vu ohjl0yp+rb3 8 h:/ jd8qways perpendicular to its velocity.

  What type of accelerati)n v1i/c ktxktajq5e4igk7 -. on does an object moving with constant speed in a circular path expe-vg4 5)c 7kq.ktxt/kj1ii aen rience?

  What force is needed to make an object move in jt/u:xdzl:h 3 a circle?

  When an object experiences uniform circ .he0vtv)s (h lpsu3q;ular motion, the direction of the net force i0;hp l3 uh.v tqs()sves

  A roller coaster car is on a track that forms a circula-6kz-ea ,q4iedn-ey q r loop in the vertical plane. If the car is to juse ezqq-4 n-d-ie ak,y6t 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 kbpdv o(ulv g90(3e .yon a track that forms a circular loop (radius = r) in the vertical plane0u9 gy ko(bve v3lp(.d. 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?

  A pilot executes a vertical dive then follows a semi-circular arc until tqq7p )uxbo7 7it is going straight up. Just as the plane is at its lowest p77o bx qp)qt7uoint, 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 curve of radk9e : m7yiw(rbab68nyius $r$ 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. g+ xf5n v 9pkr)ghaqb 8ea69w7 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, compared to the firr+wq 7a6xvg89pfh5a ke n9g)bst time?

  A car goes around a curve of radius r at a constant speed v. Then it goes arhvl t9 4iq:x5lvuh(w; ound a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes arhl;xwtv5i4:uv 9lhq( ound the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r hyxdj u2i;p: +ukz8nywi)00u. i j u4uwith speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizozu;+duu:p iy8i0 xwn04uu.ijkj 2h)y ntal component 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 samon6lq* bvy/-n72 d 4z3 q hcet/xa5j9p-enhgre angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smalle 9qexa/dn6peyv4-z 7tnno 3-h*2cqg5b l/hj rr radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobslek:zk n y,3 0+t*jovnmztt(o u*i1)ycmd track 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 the turn. Why do they do y ukk(o0yt3jm**tv zi c mo z)t1,n:+nthis?

  Is it possible for an object moving around a circular path to have 65 gwszy;t-c qbj(+vy both centripe6(jyt;q cgzb-yvs +5 wtal and tangential acceleration?

  The gravitational force between two objects is rixylg4l w4 5yo 7f s(-i*ojj7proportional to

  The gravitational force between two obja g( 1l ojtk pwlqov3+(etyb5/0pt7p0 ects is inversely proportional to

  Two objects attract each o 0p(b chx kg*;pz7xn+rther gravitationally. If the distance between their c0r*k cx7(bpp;nhz +gxenters is cut in half, the gravitational force

  Two objects, with masse)bmdcdys4oj+.)kbfc:qm a0r;r j+ y0s $m_{1}$ 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 maeof-jql90m zcn )e9 8-5g mv*o 5isclisses $m_{1}$ 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 universpm h-4 7 yh3nrhtmqt;f+m3a u+al gravitation.

  Compared to its massfjh0 cdktfsznx90 /7+vrc-t . on the Earth, the mass of an object on the Moon is

  The acceleration of gravity 6y kfp8b pa4 6e0k1(zsl p5qpvon the Moon is one-sixth what it is on Earth. An object ofqk6ypppa40 1flskbve5 z(p 86 mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfa 8pa)kel p::+qvbvcokd+s3(kce, the rocket's weight

  A spaceship is traveling to the30 oxz* 0dmddf;71)q q +vlnqo qoinv7 Moon. At what point is it beyond the pull of Earth'di0) qon;37qdqmv +7 o0 o*ldnzxf1vqs gravity?

  Suppose a satellite were orbiting the Earth just above the sf vkv+1w)u g8rurface. What is its centripetal wg1fv8u+rk) v acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius oflmj) 7(1ryb wx twice that of the Earth. What is the acceleration due to gravity on the planet in 7bly)w1(xmr jterms of g, the acceleration due to gravity at the Earth?

  The acceleration of gr.sk 37u7djk soavity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. Ws k77o3jk.sduhat is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but p 7osb7y ,5f xfnd,as)planet B has twice the radius of planet A. If planet A has mass m, what is the mass ofbf y dsx5a7n,,7f so)p planet B?

  Two planets have the same surface4rx b,h317fm v.bmn p)o0 ehlayz-wr6 gravity, but planet B has twice the mass of planet A. If planet A has radius 7 4r hxb rh.mlw)me o-v,6p b10a3fnyzr, what is the radius of planet B?

  Consider a small satellite moving in a cirlps5 ;+;tgmsw4nsz b elp -jb+qsmh8 57)o:cycular orbit (radius r) about a spherical planet (mass M). Which expression gives this satsp m+nlsb) y4;g-emqlp jb 5t7;ss:h+8o5 wzcellite's orbital velocity?

  Satellite A has twice the mass of sat;o0o:5fac+zl ow8au i ellite B, and rotates in the same orbit. Com8ooao+ 5wuaci lz; f0:pare the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating down*or 66m(mvk 52osb npoward. Compare the r56o26pkmb oso r*vn(meading on the scale to the person's true weight.

  Who was the first person to realize that the planets move in eli; nczivg:muoq*;i; bt, i66wk: /zghliptical paths around the Sun?6t 6ui g,h *qmi win:;;bc i;zvzo/:kg

  The speed of Halley's Comet, while trawgt 4u8-9t udwveling in its elliptical orbit around the Sun,dt9wgt8 uuw4-

  Let the average orbital radius of a planet be 9+a+;b wzs tph :qow 88oy4imnR. Let the orbital period be T. What quantity is constant for all planets orbiting the S 8++y;wan i4op:o 9t8zmhswq bun?

  A planet is discovered to orb-+(w m p6fpbox a qk8c8e*2wubit 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 will the period of revolution of pa xbu(b-wf2 *6coqep+8m8w kthat new planet be, compared to the Earth's orbital period?

  The average distance fromh ugd*7actlz9y)a53w the Earth to the Sun is defined as one "astronomical unit" (A*a9hzg7d w)ylutac53 U). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. en0hd 4rjo0 /ct8ir6e

  List the four fundamental f;5f p+ :hqc5sd xgfy5dxh19 biorces in nature.

  An object moves with a constant speed of 30 m/sv1 ,;z+mwu2e e 9rbhan on a circular track of radius 150 m. What is the acceleratio2nvb19 +u;m wrzh ea,en of the object?

  The maximum speed around a level curve is 30.0 km/h. Wh)l erp9sr xpb0,3t2xvat is the maximum speed around a curve with twice the radius? (Assume all other factors r)2 p9 ltxbrrse0 3vp,xemain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicy*tyq- v m;qq.: /)i8 xfw;xieig 7twfdcle wheg7/wi 8ie fxq) .vd:mtfxwtq ;y*;i-qel of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 re cagpm04 st aj)q,zb17v/s is located 0.200 m from the axis. What ip,b4aajs 7)tq zm1 0cgs the centripetal acceleration?

  How many revolutions per min,-g6f v.5b 0dninrzykute must a circular, rotating space station of radius 1000 m rotate to produce an artirnb kgyd50f.-,nziv 6 ficial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes /*ox;ua) /zmhr2fjxi0 yv xk,around a 13.7 m radius turn at 96.5 km/h. What is the centripetal xm* ha/0k2ouij)rz , xyfx; v/force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string.q7*5:voe cel+.ujmp z The system is whirled in a horizontal circular path. If the maximum tension that the string can withstanveqp*z+:e 5j7uoml .cd is 350 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is at q 7;.fwsx;l31ohzqmtcs: ;sjtached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stone's sps;7fsq t.o; sqwj:m; cx1hlz 3eed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical (r+i,-kag voz circle of radius r. At the exact bottom of the path the tension in the sv,+zagrk(i -o tring 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 ouptg7*(4tb.h o *fjpqgl.hi6zt of the dive. What is the ra.zp( i**gj h6fpto7.l bqght4dius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the cente q)(: zt1fjdfnr of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with onf (1tjqfn:z)dly one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. Whhd d(s h(qdlf3-60uu9ujgr1g at is the minimum radius of curvature that a jet plane's pilot, pulling out of a v-30ddl u9fgdru( hj(qg6 1hu sertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the t;qvm,k q,oya/ brp. o7ires 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 boq rq , a7;ok.pmy,v/surface.)

  A car is negotiating anb/1une2axi : flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by friction 1:uin/2 xbaneis $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 m at a spee3ns8;au uu1.wgcg - bn1j -pct gy)jd6d of 14 m/s. What must be the minimum coefficient of friction beuugjt cnywg8a )6bpu g3cn.j 1-d; 1-stween 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 co2r o:fb wec94 hjz)bn8efficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car :bwj e942fcbz8rnh) ois to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate aae;)3kaxy y +a 100-m radiuy;e)3 xaya +kas turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on 8zm(ffr zy6fq)iy;-fb3 o4 un 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 ao,(nz,dg ki+wiykh6 * n angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is b5hm le+,sn a(mv m fy-1zh5b2cnsc5d0anked 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 unki6d.k7pq skrz i 2.s.2vg:mqiformly in a horizontal circle of radiu2.2sd7mqsgr. kvqz.kiip: k 6 s 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 accelerati-pflivw-f1(3x9 khz) s h lt8es at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in the b)3pf(sfx --9h ill1k zvh i8wtlanks)
(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 cons.sjzy7 o9/kezr v2 y dwgez157ists 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 gravitatiqz* p3o c22jqym y8fu9onal force on a 70-kg person standing on the Earth, due to the Moon? The mass of the M82qfu2m q*y3o p9 jczyoon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force betwd)s yko (f7/dnc-0ovzeen two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attracy)n-dczdoov/ 7( fsk0 tive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from th3lf p ,c;4bcoue Earth will the gravitational forces due to the Sun and the Ecb;p,c ulf 4o3arth 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 is am+lfx 5mu+psv l 1b*($7.4 \times 10^{22} \; kg$ 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 ae lqnk1e5o p./u5f g1z "space-walk" at a distance above the Earth equal to the /5lgzqneuek pf .o115radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance abovehet ( 8upij5tq 4ah7joqtb //x+l0fq6b1nu: p the Earth's surface will the4 6hjup85nf0qpq( lqx/tbu/ i+ hjb 7e t1:ota acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equald3p) jj-io50 7yjj-rru;mlcin i:7wf to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the 3:jfl7-wirmi n-5c 7oipj ujjr)0 ;dysurface of Mars, is

  At a distance of 14000 km from some pl w4o,ggh 2cffdn21 ,qxanet's center, the acceleration of gravity is2,oc1,hgwnq 2 4df gfx $32 \; m/s^2$. 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 Eartcfpq * t,d4t*eh. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is its weigq* t*efp tdc,4ht?

  By how many newtons does the adb6z0: cm lykx f*y/*weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean ra6/abyfx m:* d* kcz0yldius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mjnfk(sz ;iyhfmk 5-0ul . ie7,1 efuc8ass 100 kg is at a point 3r above the Earth'i0 hue-zfflc;.fe yks51 7nj m(iku8,s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the E f)bd6f1 8ittd1-:2whvo tm pzarth'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-dmpt2 dihv:1f f w)61z8bo tt on the surface of this planet?

  During a lunar eclipse, the Moon, Earth,p1 74sjrf( )f dhe1dzy and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass jfdfh zsry)e47p 1d (1of $7.36 \times 10^{22} \; kg$; 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 r5y/i3h *zkam9mhms:if4 a)h 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/xdo0 0m us)3zvj3 fe yv4xvy0rfs)v 9 the Earth (i.e., it just skims the surfa juvfvxseo30f4z myv 3sv/) )r9yx0d0ce of the Earth). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it just sxqyw+u5e;qah zij4 x)ikc / 6g0 ut5g-kims the surface of the Earth). How long does it take to make on6wu t/yki ;4juea0 +5x qhigzqg5-x)ce 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 of 04/s3 v pqqr ym:h1zieed5 -kkthe Earth. It is observed t3ze 0i-1ksy/pvkq r:4ehqd5 mo have a period 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 dbj mc9:( )hkloiameter 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 m,;8c cwjik9ws* y,zkorbits 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 in nearly circular orbits. Moon A has orbital radi y+ vkmf :18y2k4b;iyjwvdii7us r, i :jfv;2w4i1ky myk vy8i+db7and moon B has orbital 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 isi -fzh7*m y7 5xanv ).crpjvq4 $7.78 \times 10^{11} \; m$ 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 isg0d(ih8:a4de ob5 nf /g0* y9wb smdwq the average distqh0/ga4g nw9 0 :o8d*dbfi w( dm5bseyance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)