Is it possible for an object ol fa(uo2k)b5 moving with a constant speed to accelerate? Explai o(bu lk25afo)n.

  Consider a particle moving with constant speed such t 9y:r5y hz5ripjpnn( +hat its acceleration of constant magnitude is always perpendicular to itsynjhrp5+9(r p: zyi n5 velocity.

  An object moves in a circular path at a constant speed. Compare the diyb/ ln.3 cjw*g7luw em;n5w-y rection of the object's velocity and acceleration vector *;/lwnyc3wb7 g5nelmj. uyw -s.

  When an object experiences uniform circular motion, the direction of the acceo6 * uombkc06z(m*bacle bu6 bamzockm(6* 0oc*ration is

  Consider a particle moving with constant speeu +0 ukdp+ qaohe;.bg.d such that its acceleration of constant magnitude gbp+qku0u;eda o..+ his always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a igfsr 2wf /fn: wp5ck:sxj 1gw2.qi,b.4 k- tpcircular p,rps:iwk: i.n tcf2 4.qfjspw/b2k -g51w xgf ath experience?

  What force is needed to make an obnpwt +z3 bvb3*ject move in a circle?

  When an object experii;/0 m,inui yhences uniform circular motion, the direction of the net forceii,u/;ih0 yn m is

  A roller coaster car is on a track that forms a circular loop ipzw j h/ q3nupw;g ( 0k*giy.d8r7che,n the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at *g3 ny.(7k j,0pchidh8/uge prw z ;qwthis point?

  A roller coaster car (mas sd*ks8a 6odd 1,nnhh/ac gk05s = 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 for its speed at that poihan51* dh6dn ,c g0skdoask/ 8nt?

  A pilot executes a vertical dive then follows a semi-circular arc until it )lj(4vgx9de6opyz *ek(xy k r.u *tw9is going straight up. Just as tr uy( xwe46g9 elx*p)9tjzy(* vko k.dhe 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 curve ofi a.qx02rww5grfot ux (x xvy2wx*66; 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 speed vwl*7o bfl8s) d yn0juko9;t;a. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes aro fbo)u7;l k 0 *l8oysdt;a9njwund the curve for the second time, compared to the first time?

  A car goes around a curve of unh:bs ,q09 usvao+y5radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is tu09 vyb: aqo+,h5nssuhe 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 cur(h1n/gb5kuz cve of radius r with speed v. If the road is frictionless due to ice, the car can still negk c(zn1g/5buhotiate the curve if the horizontal 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 sa w8-mgo-q5ucx;o;bd z+tq;( t.lkhcx l1kci 1me angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller rg -tkzqb; w ;o1umtok ccxid lcq-(1h58.;+xladius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled trac ;0:g.d:+j )ppyn q3syhbnyx qk is not constant, but increases upward from the horizontal. Coming around a turn, the b ds)pgqy.;:hy+ 03njp:yxq nbobsled 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 movinq-oi 1 /4vc0h:yftghsc ke67 fg around a circular path to have both centripetaliyth/c6 ckq10e4 vfs-g: f7 ho and tangential acceleration?

  The gravitational force be,6/7 lszcrne li5/ecftween two objects is proportional to

  The gravitational force between two objects is inversely pwaxkt yl /00r9dd4/q proportional to

  Two objects attract each other gravitatioo5p6zz(m va3xnally. If the distance between their centers is cut in half, the gravitational forc(zvo pax 3z6m5e

  Two objects, with massel50v c/dhtw5 fs $m_{1}$ 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 masseyx+mn2d,zlc2 0lwts gow6,h: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 q; 9/ /a/ rawcoouhpx0universal gravitation.

  Compared to its mass on ph d* rqa8hna1070g;zx 2zrzbh lq 87ethe Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is onn3,j75u ezs v5 :v).lkrkyxiu7oi l1d e-sixth what it is on Earth. An ob7i1l k5k 5n jzo3,ur udy7)viev.:sxlject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from t -42re jrmdzf(he Earth's surface, the rocket's weight

  A spaceship is traveliuz5; e.a,zbta-vbjnpq20fb2 ng to the Moon. At what point is it beyond the pull of Earth's g05an2btu.zfbe-bap;,q v2j zravity?

  Suppose a satellite were oex+ b ,qyi)fh p/5:duvrbiting the Earth just above the surface. What is its centripetal ax b,)fqp/iey +uv5:hdcceleration?

  A hypothetical planet 2cf- nm5)nbql has a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on t 5nf2 qmcb-)lnhe planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravitygx;wqg bx+g79n gnk :3 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's mass compared to t93 wbgg 7n:nx;kxgq+ ghe Earth's?

  Two planets have the same surface gravitm,s/+(pm 1s no:wu qdry, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planr+um1wo: /smq n,(sdpet B?

  Two planets have the same surface gravity, but planet B has twice the mass +xztn *y 6 cpm)cg l,8 n;c;h3d2qujhwof planet A. If planet A hasnzh6 ;2g cmt h, 3;qwc 8uyxp)+jcdnl* radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) af3:518cjqrww)iin mm i, 0kk kbout a spherical planetm1rwi)i: ,0m3 8 5kqkfnkiwcj (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in tki7 5yb 3tx u(dwlqd72he same orbit. Compare the qtd5uk2bl3x7 iyw7d( two satellite's speeds.

  A person is standing on a scale in an elevator accelerating mgdc *hldm k-f6(mv37downward. Compare the reading on the scmmc(dv7lkg 3d *f-m6 hale to the person's true weight.

  Who was the first person to realizki-x)+fc0f o8l: ks lncnw7f3 e that the planets move in elliptical paths arlno nf+ 3sc0klx c8kw)i- f:7found the Sun?

  The speed of Halley's Comet, while traveling in its elliptical 2+0lf/l2 rk8r3cxozl3 t ji storbit around the Sun,olr0 /fk3zlij t 232ts8rl+c x

  Let the average orbital radius of a planet be R. Let the orbital period:v persr/xd 0o-v2hco4i n( 5d be T. What quantity is constant2 5vrd/rs vdi4eo-pcno :(hx 0 for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxyn)pbtitr,xw4bx67 2x 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 that new planet be, compared to the Earth's orbital period?2wx )pn,bx7i4 6brttx

  The average distance from the Et;y4o3/uncghq- dgsd,xk 1/4i1 ryb tarth to the Sun is defined as one "astronomical unib3i/g; d4ydu4-/qx ohsk1t 1r gct,ynt" (AU). 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. 40hj0tfnqlk/

  List the four fundamental forcesjy4hgq 1m:bk4l3uha ( in nature.

  An object moves with a constant speed of 4wf.* 4byvly j30 m/s on a circular track of radius 150 m. What is the accelerat4 j*bw 4ylvyf.ion of the object?

  The maximum speed around a level curve is 30.0 km/h. Ws99:2b/dr qei xlkyk2 hat is the maximum speed around a curve with twice the radius? (Assume ae yl s9k:rk 22dqbx/i9ll other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bit8 z9r8oyxd n7g6m w/rcycle wheel of diameter 70 cm when the bike is moving 8.0 m/sn7z/tm8r9 x8wor6 gyd?

  A point on a wheel rotating at 5.00 rev/s is loca k(idxz/q t52rozw+j;q d.*jqted 0.200 m from the axis. What is thjo*5rwq+i /d(dk 2xzqz j ;qt.e centripetal acceleration?

  How many revolutions per minute must a circular, rotating space staw)zp: xbak/ z50f 1axtz;pm :xtion of radius 1000 m rotate to produce an artificial gravitwzz5;:pz1a:x )ba0/pxktm x f y of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13a8 d, ltcpid9;c0utrq u90a,h.7 m radius turn at 96.5 kc h td,i,9ta8u0 pr90da;lu cqm/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirlex mw9we3 +y87ywsdxq/d in a horizontal circular path. If the maximum tension that the string can withstand is 350 Nywywq s7wd+ xe/3 89mx. 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 5 f mtqdka-kv 0mz;6y(in a vertical circle of radius r. At the exact top of theat y-dm6;5qv kfz(0m k path the tension 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 str(q kpesin( 7izfk;/*pong 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. The stone's speed at thisp*k(i ;s( p7e/fi kqzn point is given by

  A jet plane flying 600 m/s experyoq,vz1hle 5/q9 ka,liences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane a/qzlleq,kvo y,519 h is flying?

  A pilot makes an outside vertical loop :hj6 7e-jdx 2nm6 cxcay;y-nv aj)qz6(in which the center 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 nxj7 :h nnajemq)-cay6dj ;-y2vx66czormal weight. How fast is he going?

  The maximum force a pilotop)jipj38c- em4(e iu can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a verpmep ou-ei4)ijc( 8 j3tical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/.rdembk0t7vi23 tb t9s rounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can thtdb 0k btv29ei 3tm7r.is car round a second curve of radius 320 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 m with a speed 5e0*c,g );f odkfnko pof 20 m/s. The cenek, dpok; fn0*g)foc5 tripetal 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 radius 50 m at asuofz7 /+ok *w.hb 6fq speed of 14 m/s. What must be the minimum coefficient of f6kbf*fozh + ouw/s q.7riction 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. The cl2 zm; lbxbf v;x5)cd+oefficient of x lz5mbx2 d;v+)bcf;l 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 the road?

  What minimum banking angle is required for an Olympic bo l 1jo:b4j3t.tr wqov q)vo/h)bsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore fricti4qjh./)wt: r1)qvvo3o bo jlton.)

  A horizontal curve on a bobsled run is bankedq6k/ oj8c8jvanvkto wb,4ez 0/nr 3p7 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 a+8m 4 qtl oxuvnrib4(z51 i5-/xxwavyngle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 u t6xlv g+;gg,3h1pfp m 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 stritli)zy c +y.6:bi+p m:yd6 uoung is revolving uniformly in a horizontal circle of rabyzypou)u+:tiy + dm:6.6icldius 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 uniform rate t-wx 6d /z(4)c5hz*vrrwesnmgo a speed of 45 m/s in 15 s, moving on a cin)mw5 zrvx4er6 h d /wgsz-*(crcular 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 proton of mfd2cbzcb (-f7 w9.bat ,q:a zlass $1.67 \times 10^{-27} \; kg$ 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-kyavm -ab,-xor ))lja 3t42h9g jlb;zqg person standing on the Earth, due to the Moon? The mass of the Moon ib-)j3ahax,t4) yz-j g olbma29lrq;vs $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive forceb 24mq .j*ffw)ww xb1i between two masses is F. If the masses are moved to half of their initial distance, whb iw.4jmq1 w fwf)xb*2at is the gravitational attractive force?

  For a spacecraft going from the Ead znrw6gphf5dx98l,9 rth toward the Sun, at what distance from the Earth will the gravi 6wgdz9lfh 5p9r,8dnxtational forces 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 Moonudj1u3 qe, f,g 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-walk" at a distance above the Earth equs9p ikqf mh8 4j: fb:1ubr tpr3.e4(leal to the radius of the Earth. What is her accel3:ipubbr4thf . (k1pej 8mf eqs:4rl9eration due to gravity?

  The radius of the Earth is R. At what disoswzih5 p1 m;.tance above the Earth's surface will the accelerahi15mp wszo. ;tion of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 timhy4m,o( acruq1 2m5voes the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, iommy4u5cao, (h r v2q1s

  At a distance of 14000 km from some planet's center, the acceleration of gravity5/nnmqf*.v ohk ymk;* tuaf;0 ah 5*;mmk;qf.k* nv/nt0 fo uyis $32 \; m/s^2$. 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 r. If y;jc 2megx 5vu 6xn6o9the object is raised to a height of 3r a;jm69vgo6 e yx5 nx2cubove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg e,rp+c9a /tl7gb /f -)ohze dbperson change when he goes from sea level to an altitu9h e,lp -g b/)+zreoc7bd aft/de 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 100 kg c3rt rlw9s:(g;u6 qnww sh.b:0,uavris at a point 3r above the Earth's surface. What is the satellite's weighta:h s r06 rw(u;.3suq9cn, rlwtb w:vg?

  A spherically symmetric planet has four times the Earth's mass and twice itsm k7+kx*s 5zvahuo *c/ radius. If a jar of peanut b7k5xzv /k msuch* +*aoutter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, thu0in * 3md flwz9u7ue5l+m/xre Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a*i 9fxrl7u m5/ 0w+3ndluzm ue 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 isj79m n+)xve-b(sn ru; h qvpu* 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 a ,o*ej a0e2kp(t 0b qgkdfnz -s0,dd9wbout the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellitk(kqets j9 ,dp0bd wdz02 gaoe*0n- f,e? (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.z+pqttp: +t r;, it just skims the surface of the Earth). How long dt + ptq:pz;+troes 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 circulx 3s lv;fpd1h12z 1gv-o(bdw:jr l3pmar orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radiusxrj1d3pv -f2 mlhgdpvs b:ow;z 11(l3 of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiti6o .2(d tgu.c;ym1v ghiei*oer, has 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 Jupiter orbits the planet wv(13 w ow+ .vpokw1jbdith 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 or0kt0 jzgj2, espz1y+d bital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. jz0ypdsz k,2egjt1 0+How long does it take moon B to complete an orbit?

  The planet Jupiter i0ukkecifg-i2zz i* *b4u 8: qvs $7.78 \times 10^{11} \; m$ 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 1qi. j/a 3,kgxnm 0bo(nx8srlgu 6(o4-+ef vnq2 years to orbit the Sun once. What is the average distance from Jupiter to the 0sq r/-,3xfnloj go ie n(gba+xu.v nmq6 (k84Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)