Is it possible for an object mo(y/ny99j n,1tasr;wk2h bscs ving with a constant speed to accelerate? Explainn9sy(jbkwh2r9 ;t1y cs,s/ n a.

  Consider a particle moving with constant speed such that4..ktv 0ck phcp0ow2x5 bb,sy its acceleration of constant magnitude is always20,sp0cwht 4.c.5ykbvxkp ob perpendicular to its velocity.

  An object moves in a circular 1 tq- *uw)cxf7tiqm m+path at a constant speed. Compare the direction of the object's velocity and acceleration vec-i*1xc+mqmf)t 7 wquttors.

  When an object experiences uniform circular motion, th kxvto-q2e4(r e direction of the acceleration2ok(4et-rx vq is

  Consider a particle moving with constant spee/si1n lvjc)f9 d such that its acceleration of constant magnitude is always p) c /91jlvsfinerpendicular to its velocity.

  What type of acceleration does an object moving with constant speed in a cev-y7 bjbhkht ; l/ :w.lxc:0vtcs6p8 ircular pat: ;sxkvewt p t.hyh6lbl /j:7v8cbc0-h experience?

  What force is needed to make an object move in a cirl4ari zadph40e7sp1- cle?

  When an object experiences uniform circular motion, the di2 1xl71kjgd qh;npd 0crection of the net force ;nk1q2lcpd h0d1gjx 7is

  A roller coaster car is on a track that forms a circular loop in the verticub*3 +6ygus2r dygpit 04yvy1al plypyut*0y s g by 2gvri43u1+d6ane. 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 this point?

  A roller coaster car (mass = M) is on a track that fo qupe0a *e5dekq46x, irms a circular loop (radius = r) in the vertical plane. If the car is to j4kua eq* 6idpeqex50, ust 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 ik; hhnqaa8p1c1xt(6r t is going straight up. Just as the plane is at i;(n6chx 1hr8aqa1k pt ts 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 of :zc.4t+ dm sxkb8/rw6yxj*rj 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 jvp rl3d2m3w/xba3f1l-6b k kradius 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 the first taxbwpfl33rmk/23-b1j k l 6dvime?

  A car goes around a curve of radius r at a constant speewc oilye4 hb9 .60o/fswcqd:7d v. Then it goes around a curve of radius 2r at speed 2v. What is70bcd:fweoy4/ 6ohw c9ql is. the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes arooo8a, /)orxycund a 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 8ro,o y cao)x/the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but:(l7 pr .mhzrzt1mbqmkffa8g)ox4*1 one has twice the radius of the other. The safe spee k1zo m (x ff.lh8rt*)4pgzm:b7maq1rd (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 Olympf)isgx;9l *w: ih ah/e69tw smd q;q/dic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn,9)t/6w i;me;q*/sh afqh:wl sixdgd 9 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 aweqjfyr6(wazg 2+48g+zyy:dvp eg )*n object moving around a circular path to have both centripetal and tangen zzeay(+pwdq yg6yegg)v*r4fj+ : 28 wtial acceleration?

  The gravitational foy -/tj 6b (9cyhf3p kr-tq4yuzrce between two objects is proportional to

  The gravitational force between to . ,pus g14bpl*y:jiwwo objects is inversely proportional to

  Two objects attract each other gravitationally. If the ao0lnl d01 ,hvcuoyq)3 .qhtxd+) qc1 distance between their centers is cut in half, the gravitational forceot+qq l .n))od3 ax0uhdql110hc v,yc

  Two objects, with masses 8k+grjtzq34p n ftzn0z (l039tc1woj$m_{1}$ 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 masses;+ bb wqt+3c4ku,f rq(6khvup $m_{1}$ 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 ohoh-82qr -ib h;rtup ;f universal gravitation.

  Compared to its mass on the 1 q:dkd: nnit9;eg6qn Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon ikzjbr +s jy4, ;-es,ryk9lc5 fs one-sixth what it is on Earth. An object of massfe9,b ykjr,j;ryc lzk 45-ss+
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rockyz6qj.rh u :qem x7i0r; m7dm ib7g41set's weight

  A spaceship is traveling to the Meqz 28kapoes; f:,v-hn1 4 nlzoon. At what point is it beyond the pull of Earth's gravity? nz2fe n 1s4oz8hpkqv a:-le;,

  Suppose a satellite b x8wkmr eyh0 f;07ms8were orbiting the Earth just above the surface. What is its centripetal ac8r e8;mwf h0bmx07 yskceleration?

  A hypothetical planet has a mass of half that.gmbvk;k8 djpjrn1 : , of the Earth and a radius of twice that of the Earth. What is the acceleration 18gvj;nrp ., m:dkkbjdue 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 i ge 1ugfe:bgpbe;,c,2 im)rj 0s on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moo,e : rj;gf0 geu)cmi1pgb,2ebn's mass compared to the Earth's?

  Two planets have the0mtpdhd )siu h/3xe f (2nm7.y(7btmk same surface gravity, but planet B has twice the radius of planet A. xkt2tu f .mihd hd/0ym(bms(7)e73p nIf planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but le0)c 9,. xrj9pgi ufv217zgqrchz, h planet B has twice the mass of planet A. If ufrxq 2peh0 zi,gc1jv,l 7zg. 9c9hr)planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving ijlss,:8 85hqnfsi 9 xs,/g cbrn a circular orbit (radius r) about a spherical planet (mass M). Whichf88,:, br59c/ liqsgn sssjx h expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotatf5zr4 /uzri6ute -:c*cjp c3 res in the same orbit. Compau3t z c6 *repr5cfircu:z4 -/jre the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downwa7 br:t*1ap, b17pctjl wvt o7brd. Compare the reading owbtpjo,c :7ab1 7ttbrl*p7 1vn the scale to the person's true weight.

  Who was the first person to real* a a;.d6dlif5t)tsqzize that the planets move in elliptical paths around 6 z;tafd.qs i5)* ltadthe Sun?

  The speed of Halley's Comet, while traveling i,p0k9b8nd pc x2fs 0 7fbc/lcvn its elliptical orbit around the Su7cbnpdp/f ,82l9v skcxbf00 cn,

  Let the average orbital radius of a /-+82mduvt9 s 7lxo ku5elbzlplanet be R. Let the orbital period be T. What quantit9b-ls 8z lk+/2dme7u otvxul5 y is constant for all planets orbiting the Sun?

  A planet is discovered to orbit ar :nq; rwqr7+ u0m,yucgound a star in the galaxy Andromeda, with the same orbital diame,rgr:0u7yqn+ w qmu c;ter 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?

  The average distance from the Earth to the Sun is defixp/ 4 ekiz82gq;i:hqo ned as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is tihz q4p:/qg82e;okixhe asteroid's average distance from the Sun?

State Kepler's laws.zu/ vtqu7ag81

  List the four fundama)bfjglm72ovt zz1 w -z.e-.vental forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiusu c5 q8iiv -+l7ma68r5abucbh 150 m. What is the accelerationv5 brac-bui5 l +q87m8u ac6hi of the object?

  The maximum speed arj-mj ta *z7hqa /1jzaa6s q4f4ound a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all o1/zaaj4mq4 fz6t*q-aaj7 jhs ther factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of 6i bt6ku6+yurqi l)y0ddy eh;;;g ta: a bicycle wheel of diay6)ge;rd 6k+bu;: y0u6dyit tqh; ailmeter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel ro.s7 d d6vjq q9+fi io7fuaxac*5n f)r(tating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal a fr c9 (i7ai.xda ff)njqo+6usqd*7 v5cceleration?

  How many revolutions pe sbtmonk2ya)xdw +f0m6;i 6h2r minute must a circular, rotating space station of radius 1000 m rotate to produce an artificial gravif2kxb 0a h n6s;dym6wio2t)+mty of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radi u5 ,a gtbagnr96/2asnus turn at 96.5 km/h,usgnt/2arn 65b9 a ga. 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 sc r4nfo4m qsj; y/u:rx5x87sfystem is whirled in a 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 stx7 rsjm :c x48/yfon;s frq5u4ring is not to break?

  A stone, of mass m, is attar,na 20 odj rl7i,4bcbched 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 speed at this point is given byd0 i bbrr2 n,jcla7,4o

  A stone, of mass m, is attached to a strong string an l1p +hmgwvg h-g20uu)p0c: b i(w34ukf w(xywd whirled in a vertical circle of radius g0ih vulkuu2gw14: (fpx)0 byp wwc+wh g-(3m 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 this point is given by

  A jet plane flying 600 m/s zm, m rf,/wz )5rwxr8texperiences an acceleration of 4g when pulling out of the dive. What is the radium 58r tfrwr/mx,zw ,z)s of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertic;n:ojmv/vywi1ky3*,t kl / dial loop (in which the center of the loop is beneath him) of rd jv/vym; it:/13n, o kyk*lwiadius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times w8lhtdaeed w,5l2 3 f)his weight. What is the minimum radius of curvature w8wh al)eld2 dtfe53,that a jet plane's pilot, pulling 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 horizontal we9, iu(oykttj 8d*0acurve with the tires on the verge of slipping. How fast can this car,9 eodjat8 t*w ui0yk( 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 of 20 m/s. Thl 81eg1 eiig6kw/om,de centripetal force provided by frdgo6/,mi81 e 1 egiwlkiction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve hl+ia-y; cu;b o7mn2b of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make ti7bo;2y ;acmbh n-l +uhe turn?

  A car is moving with a constant speed v around a level curve. The coefficient(v(0*r,xtw y d t/njti of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the c itt,nw(tv r/ 0j(yd*xar is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiat wzrfd;b(pde1;d,tme hy,)v6e a 100-m rad,; d wmvr(eyz1dpfeh ,t);db6ius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked ah/1 pryvpl40et 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 100w59q2hx. o/ 9b8oi.:pimojhx m+cf;r sj fwp0 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is b+ maj qm*l-7o95namduanked 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 i8pcmdvdzc/9wfjn q tq08-b 5c f w)0e(s revolving uniformly in a horizontal circle of0f c5cw ddj/( b8pnemqq)w8tzcv90f - 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, a race car acceleratee69 cm 2l8lhtfz *rji3s at a uniform rate to a *z2fr 6el9hlic 83jm tspeed of 45 m/s in 15 s, moving on 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:wjscd:*put e9 luag2x:u7t(u( sf3x 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 force on a 70-kg person standing*4i/4tg zn5,5zm: jzeb7 4r hkpsqmnh on the Earth, due to the Moon? The 45r i5t*g /4zn7mnpk4 :bzzmehjs,qhmass 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 betw2hjd8suv 6 cj3een two masses is F. If the masses are moved to half of their initi38j2j dh 6ucvsal distance, what is the gravitational attractive force?

  For a spacecraft going from the Earea1. +b) fw0xsb ns5sath toward the Sun, at what distance from the Easb1 s .+n)as 5fbawx0erth will the gravitational 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 Moon is+d(bmu ahpo8 0 $7.4 \times 10^{22} \; kg$ 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 equ)f1dm7uhvlt 8 al to the radius of the Earth.vd8mf) l1 htu7 What is her acceleration due to gravity?

  The radius of the Earth is R. At k/k+f jal*.tlq9(uam what distance above the Earth's surface will the accelerat.j+m* (lqla /kfk9utaion of gravity be $4.9 \; m/s^2$?

  A satellite encircles l t(;ocdt*az9d qzdxo)l +cpd3a)2 *yMars at a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Maq+)t 3ddzd opldc2aoa * c*l(z9x)yt ;rs, is

  At a distance of 14000 km from some planet's center, the accec.oitr as7 z-ygmo,bx-:r243j8a yx pleration of gravity is j7--orra, c oy:xx3amz4ip tyg2.8sb $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on thywjv )nc;)s*g c(b4 the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Ea)b;)y(hsjwcgv 4*tc nrth's surface, what is its weight?

  By how many newtons do-g dqpjg80:hyes the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth is :pqgyhdg- 8j0 $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass kv t( 9p zwj.u))paky(100 kg is at a point 3r above the Earth's surface. What isa. ( k)9zvp(kytwu)pj the satellite's weight?

  A spherically symmetric planet havdk *+ff l x3;5auq e-jdk/ts:s four times the 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 plaf 5adfj-klds: v3 *k+txe;u/qnet?

  During a lunar eclipse -f0lmqv 8np)f, the Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass omlp0n- q ffv8)f $7.36 \times 10^{22} \; kg$; 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. . q3.v( zx2pkz1l exvu
(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 f c m2-n el.isxiv23/jthe Earth (i.e., it just skims the f2m/civln j3. xse-2isurface 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 th:03i8yo/hjj9k;(o8 4v hxi uhmyaf k xe Earth (i.e., it just skims the surface of the Earth). How long doe;xmhu9j:a/j 3y0h 84ohvoi8kf kx(yis 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 th 3vo20hgn94 sxwei gw,e surface of the Earth. It is obse0vsiwn2o gehg4x3 ,9 wrved to 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 diameter of/ft8auac rp 79as 7ll-r pq0k6 $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet wl5b1y zj+q- cyith 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 r5*4 ois a3pqhbadius r, and moon B has orbital rad oaiq3 4*pb5shius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is g5x54l *a 4/zg wtpdky$7.78 \times 10^{11} \; m$ 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 yeam+.0pipkecx22 d) xe qrs to orbit the Sun once. What is the average distance from Jupiter ie.q0x)2 dmxcke2 +p pto the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)