Is it possible for an object moving with a constant speed to accele,c c.e nwiq*(nnp/ *pplnc 3p(rate? Explai/, ncn ecc.pqn3iw* *lp(np(pn.

  Consider a particle moving with constant speed such that its acceleration of cv/u7tp 5n (ifronstant magnitude is ali t/f5pnu7r (vways perpendicular to its velocity.

  An object moves in a circular path at )-.pdpf4+vjexi0owduyn)* pa constant speed. Compare the direction of the object's ve p. ej)yxpnd u)o0-* i4+dvwpflocity and acceleration vectors.

  When an object experi gsd + r;hr4,aicu)ps7ences uniform circular motion, the direction of the acceleration iicr;g a d+4h)su,srp 7s

  Consider a particle moving with constant speed such that its ac4r7ih, xmna 9ck 7nm-pceleration of constant magnitude is always perpendmkrnh7an,x c4i 9- pm7icular to its velocity.

  What type of acceleration(b1 no.u,3 kjl6lfjea does an object moving with constant speed in a circular pathnlajb kfl u ,o3(16j.e experience?

  What force is needed to make an obexi/y/fw -c3ze)r )jr ject move in a circle?

  When an object experiencesh :;*fclxiwj d9 xmq;* uniform circular motion, the direction of the net force *f;xd :i;q hcwml*9x jis

  A roller coaster car is on a4yqg-1gl2b:e mx0elp o pg/5u track that forms 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 minimum value fo/gl4m5 1g eul0 e-2poxybgp: qr its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circulacb.49q nc7ain r loop (radius = r) in the vertical plane. If the car is to just maintain contaccn4n9ic.q ba7 t 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-circum9 ew,u2+d 7x- *7h.fh; ntvzmpq aefmlar arc until it is going straight up. Just as the plane is at its f *hm-txvd +ehumnf a,7.q;9emz2w7 plowest 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 curve of 3h3vip ry a i+uk;wkab*t,r 58radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radiucdnhgbk56 x p ./,8oyus 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 car as it goes around the curve for the second time, compared to txn/g6p,8 5b ho .cuykdhe first time?

  A car goes around a curi tf:; b9ojcb fqfqwh(pk)-/tm4w4r0 f, hwu ;ve 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 asw- p qbo ;mih/;rc ,t4 4wfbfwut):jf9k(hf0q it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v.b,r+ b uybpayi; .k36ztg;4h z If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal compon,;b hpbaz z34irk6gu;. b+y ytent of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run aiw2 mgzw.2c t(6:4vmygt yz6gre banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) fo(2tty: i2g 6yzgmmzgv4. wcw 6r 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, bu.n 1eoqu1 fp7b,:qiw dt increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "c:1qqno uwbpd f71e.,ilimb 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 have both centripn l3mg0gz,qnf.yt / ip nvq,23etal and tangential accell nygv ipt, ,3.g/qn20mzf qn3eration?

  The gravitational force betipp+ r4xru /de.) lg;cween two objects is proportional to

  The gravitational force between two objects igq/ m -wxonsef78f:i (s inversely proportional to

  Two objects attract each other gravita/xz5fbsgnv+4fkihd(u nr;6k8gyn 6, tionally. If the distance between their centers b rd8 zkhff6nn, g6/;y(invxskg u+54is cut in half, the gravitational force

  Two objects, with mase v*8bay8m / /kgwnq*sses $m_{1}$ 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 massewd dn4oh +ld1g.7tz b*behi(.s $m_{1}$ 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 gxx9*dh tdy+dtp :. ms5ravitation.

  Compared to its mass on the Earth, tbjl90 ks+w4ithe mass of an object on the Moon is

  The acceleration of gravity on the Moon i;n 0cthu )3eek rko5j-s one-sixth what it is on Earth. An object of mnteh5-0) r ekoku jc;3ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocke; cd.ud m3hzv:u0eh2bt's weight

  A spaceship is traveling to the Moon. At what point is it (c00eck;kc*ukuv a,gh:3it k7 edek,beyond the pull of Earth's gravity?uk kc:;kkv e,0aec(h7cde*ig,t u30k

  Suppose a satellite were orbiting the Eart tr)- a:w,qumfh just above the surface. What is its centripetar)w:afum tq-, l acceleration?

  A hypothetical planet hazrdow u925s l,s a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to graor,wzu 52s l9dvity 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 h n2xx+k w.f(sis on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Ea.fn( xw2 skxh+rth's?

  Two planets have the same 8 d79-q ujfcgfsurface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is 78q9uf cjgdf- the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of pfcw r);jadw0 4lanet A. If planet A hafa c0;rdj )w4ws radius r, what is the radius of planet B?

  Consider a small satellite moving h)5aoy kh yjam n zq5(i)o8+a5in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellinoh yakaz+i qhy58jom5a)5) ( te's orbital velocity?

  Satellite A has twice the mass of satellite B8 iyq2ol hhy4iws7m b+r69 e.-1e raqr, and rotates in the same orbit. Compare the two satellite's speedsr1meq ylyh i6o9r rw 87-4 a+bs2hq.ie.

  A person is standing on a scale in an0awv-lymm-h 3 elevator accelerating downward. Compare the re yv0 -mlwma-h3ading on the scale to the person's true weight.

  Who was the first person6u7alxxw) f) l to realize that the planets move in elliptical paths around the x))w6all7xu fSun?

  The speed of Halley's Comet, while travee3ev5oc 68flidj8 o l/ling in its elliptical orbit around the Sun,8 j53coei6o /l8vel fd

  Let the average orbital radius of a planet be R. Let the agg4 av8g1xcl- nn9d6 orbital period be T. What quantity is constant for all planets orbitingv1 l8gdnga49 6xcan-g the Sun?

  A planet is discovered to orbit around a sx l19l4eox h -z83edyrtar in the galaxy Andromeda, with the same orbital diameter as the Earth ar e18del-lyx r3 4zxho9ound our Sun. If that star has 4 times the mass of our Sun, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined ,er;i n*x;uymas one "astronomical unit" (AU). An am;*y i ;uex,nrsteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.dqj fyc.rf x,9*rq4xe b5l*h5

  List the four fundamental forcesh2q,zyqe710 lxdo aa9 in nature.

  An object moves with a constant speed of 30 m/s on a circular trac(87 zq yh ropbed+c3ur7/8 d.jgqm/w ck of radius 150 m. Whcdm7u8/j bq7/g d.+ ozre8rp cy3 wq(hat is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximuw2io.ahk:ck o;95hz fm speed around a curve wif29w c;:5.kohizoh akth twice the radius? (Assume all other factors remain unchanged.)

  What is the centripelny )6vjd6dtk+i5j; j tal acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/sy56j vj +tkdd;)j6l ni?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axix g ofhrm62/2;vskla3 s. Whatg mf/vrxk3l;6o sha22 is the centripetal acceleration?

  How many revolutions per minute must a circular, rotat c(0hr998iumdj iu;deing space station of radius(ud0;h9c9ui i8r mejd 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It gonbf h yb;kzayly,m;25 o -82 zzau)e7nes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the mol 2-umyy;e27 8;fb5no)zh,nybkz a aztorcycle?

  A 0.50-kg mass is attached to the en 2ou ejc5(vkw e3o01qbl ac,ynv49jq: d of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension thatc vwe 04bqe 9jo3 ok1jc2(lanyq5 ,:vu 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 whirled in a vertical jhy/2bhr2 bbhw5ukeg.:4x, e circle of radius r. At the exact top of the path the tension in the bekbhu:.h5w 2r24,/byehj xgstring 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 strinqvx*:twbq/b qj- s6d5g 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. The stone's speed at t* :6qs/-t5bq wqd jbvxhis point is given by

  A jet plane flying 600 m/s experiences an acces41 r ,4vsljx-,q1krk ;imcpmf9n h, nleration of 4g when pulling out of the dive. What is the radius of curvature 1 ,nxi q,ckvhs1 mr94mlks4;nr ,jpf-of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is bens8g+b,eo ;b rxeath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only onesebg8x r;b, o+-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand s-q 276yus9tnb 6nrq em0rl; sis about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, puym2 b9sen;r 67 u0snr-t6 qlsqlling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius ho,q3d,pjxl 21 g 8qnripu ,4nwirizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320rn4p,x 2 ,l31dqq 8uinipwg, j 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 wbxz )d;6z1i6mogvv 9 engd8/ m with a speed of 20 m/s. The centripetal force provided b6 d1) 9zvdiwgm e8;6bxognv/zy friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve w1rxi qrdg0+/of radius 50 m at a speed of 14 m/s. What must be thwrq 1gi/dr+x0e minimum 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. ci9lt j0i e)97k svyy(The coefficient of friction between the tires and the road is 0.40. 79ktlyv j09i(e) s ciyWhat is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is re1f v6oojm s*8equired for an Olympic bobsled to negotiate a 100-m radius t*moj fsev8o61 urn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankeddo0)e 1 ;/wres extg7y 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 ra4o5dn i: wmg84l5h7 9hrjlohot5b( ohdius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked akf cr,pn8b51u4 m 5t3jfw 4iegt $45^{\circ}$. 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;h6lbxmaq8r(jw( z .a is revolving uniformly in a horizontal circle o.8;b w(6zj hlam(rqxa f 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, vopjf6,5 nj3.-radvehw ws ) )a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a cpj3w o vd,5-)wh6srv)fenja. ircular 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 pgeog0dh.48f2ehu/ qs1iq k+eroton 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 on the Earthf ciur8u gqs+cpe pqyur386 z;tw9,:4, due to the Moon? Th;+fgccuy:ziu ep8p9w tq86s r, 3ru4qe mass 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 force between two masses is F. If the masses -kv:jb/dgx h3b;(v41pyu gwh are moved to half of their initial distance, what is the gravitational attrk3dwp-j 1 bbyuh;:hvvx(/4 ggactive force?

  For a spacecraft going fromoc /fxr53.q tf the Earth toward the Sun, at what distance from the Earth will the gravitational focftqo35 r. fx/rces 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 Moon1t)unp9 q8up f is $7.4 \times 10^{22} \; kg$ 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-walkak,i(v .qlns6 " at a distance above the Earth equal to the radius of the Earth. What is her acceleration due to gravit (v,6la.nk qisy?

  The radius of the Earth is R. rqv4b96 *i)d d *spbywAt what distance above the Earth's surface will the acceleration of biy46)wrd*spv q* 9 bdgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times xto s3ud 6pxjil;1f4o+ )up1 fthe radius of Mars. The acceleration of gravity of the satellite, as compared to the accelerxd j3f1 6 4+;ultpoui fxo1s)pation of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the accel;ujzi,ae* j1 )bu q)hoeration of gravityjiu; 1 )oe,hzja *bqu) is $32 \; m/s^2$. 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 Earth has radius rffiz3),8eac 3rprj: r. If the object is raised to a height of 3r ab3,: frr38jfp c)iaerzove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he gsugbw( jw8 v/f1 (k9ncoes from sea level to an altitjscn wg8k(1/fbuv(9 w ude 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 k8uy9brxji9 :* v6lvy100 kg is at a point 3r above the Earth'sk9j:yrlx*8i u 9y6 vbv surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its rayi ff*r0 m4 *wb ,2lewu,ppsn5dius. If a jar of peanut buttp0fe*4nu*, b 2 rp ,lmwifswy5er weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclip*k/x jn6kj1 qjylb2y4 se, the Moon, Earth, and Sun all lie on the same line, with the Earth *jqkj1nbj 4/yy26kxlbetween 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 is transported to the Moo4t1+zbudn)z uewmufw84 q-, i n.
(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., i*s lc tgq95uv)vp2,bany10q y0lky6 ct just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth i5 ,*9c1pys6akbuqtq 00yll)2 gyvvc ns $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about gipt afm/0 62kthe Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Eartamt2gi0 6fk p/h is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. It ii902 yyrp1vh js observed to ha iy92pvr0jh1yve 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 orbita.xv rdn( h68m gh eg8lj:s+ro,l 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 ;ujga c xp 65hzo 1lca-ywe-55radius 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 h ryx.g(/nb ktaw9x3-nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long doer. ( abh/3tkxwg -yn9xs it take moon B to complete an orbit?

  The planet Jupiter isf bhp7p eu(3:s $7.78 \times 10^{11} \; m$ 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 qt)jn 0uzdh/qh h/sb d1a,eo o+i.i87 Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sun ije,hqso0b/odz 1+dqu8)tih /hi7. na s $1.5 \times 10^{11} \; m$.)