Is it possible for a1(iv)sp0iq:cr hs:o b kds+o2m 6 x/wxn object moving with a constant speed to accelerate? Explaiqrw 6:sob 2sid+x:x)i1 cmos 0k/h v(pn.

  Consider a particle moving with constant speed such that its acceleradr4 wmtc8yvuvq y:* cd1)v2j:yb (xu:tion of constant magnitude is always pv)du tr2yvyvmbdc:jx:(uy4 :1c *qw8erpendicular to its velocity.

  An object moves in afqf47eqi c3/* :ob9jm.q ufpd circular path at a constant speed. Compare the direction of the object's velocity and accbdofp *me.j4fq/7uif: q qc 39eleration vectors.

  When an object experiences uniform circular motionje;b yn oiz*cl2/ v8z:y/jud+ , the direction of the accelernv8j d+y i2lc:z u*/ ey;bj/ozation is

  Consider a particle moving with const3at3pg7 2kezp6n 6-0bvrvse nant speed such that its acceleration of constant magnitude is al-v n3 g0srzetepbvp 273n6a6k ways perpendicular to its velocity.

  What type of acceleration does an ob2mwu csl50 2bifwf2/2wcel r.ject moving with constant speed in a circular path exlm2wc bww0c r .l25iefu22f/ sperience?

  What force is needed to make an object move in a circl*lnctat* 7p -rzv a(eg1a(ag(e?

  When an object experiences uniform2v:0 pp dabqzgev -v*eo6o5 o* circular motion, the direction of the net force ip06opv:eq gob2v* *5zdo ae-vs

  A roller coaster car is gvw(yc y ps,q,*i2u cye25ip:on a track that forms a circular loop in the vertical plane. If the car is to just maintain c*i ysvq25ie,g u:p2cw,(pyy 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 forms a circular loop (radiuse z: hnxous. op9lm-u4s0b/n/e -t m.z = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop,n/h.z-ol 0p9eoemub.xt:sz-m usn/ 4 what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circulaibf+q b*z:g-ar arc until it is going straight up. Just as the plane is at its lowest -z*i+g bbfq: apoint, 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 ofl23gey*ix.pmt 7a ( qx 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 v. gnlr4s9nr(8x3()g q ktosn .h 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 fo ns8(.qsn g)9hl3rt o4xkg (rnr the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Thmn; )jdbs gn9jkp 3,rno7kd, 7en it goes around a curve of radius 2r at speed 2v. What is the centripetal force on thek )n,o,dk m3n7sbjpj g97;nd r car as 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 rezet,e)e(wru.( p2m . If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normat,e erm(.p r (z2e)wuel force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same anglpim1fs )( wf ks/xe5c7e, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is 1 5kmffecxwsp)(i7 / sv. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is :;7gp v9hbaq yd)d4op not constant, but increases 9 p;vd7aby 4hqdp)o:gupward 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 this?

  Is it possible for an object moving arousey9*al m/9k c:ipno )nd a circular path to have both centripetal and tangential accelerationneoapkc/ 9li :y9s) m*?

  The gravitational force between two objects is proportiir1 ohd(/7rmarjzi / 4onal to

  The gravitational force betk,ef t(8h.4w c9e .eve7: efv reb.qknween two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance betweenx ms1(us h(xce7rm:)zw:gurh j0 ,l3c their c 3s w lhzx1hxr0 7 jucsum:(re)c:,m(genters is cut in half, the gravitational force

  Two objects, with maw+(uhmlwz3 +ktqw:j -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 mass- g-thrc 7ihkvk ap;a d/r,18ges $m_{1}$ 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 uni08emd mmemy+i-8+ptj pbzm7:versal gravitation.

  Compared to its mass on the Earth, the mass of an l4 rnltbk0 mo (;by,:aobject on the Moon is

  The acceleration of gravity on the Moon is one-siiu0oivyw7) g6 xth what it is on Earth. An object of ma6i7ywv) go0iu ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfas5kr(u b+)+go1rhiqul o:ia) ce, the rocket's weight

  A spaceship is traveling to the Moon. At what poinokvnx2lmgxfce +o 9 :y-8vf4w0d2f9k /q udu:t is it beyond the pull of Earth'sf /kqv2kd 9yo9ux-u2d+xg:wf8v nm elcf o:04 gravity?

  Suppose a satellite were orbiting the Earth just above the surebqqo15 /wz.yface. What is its centripetal accelbz/ yq 5ewqo1.eration?

  A hypothetical planetrsax0,u.4p3 b2pr dui m;njh; 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 the planet in terms of g, the acceleration due to gravityjrp 402;hib3 rd;,aupums .n x at the Earth?

  The acceleration of gravity m4-ln3fmdos/on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What isdf-sno l 3m/m4 the Moon's mass compared to the Earth's?

  Two planets have the samc 1v/(wb b9gype surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the masswp (b/bgc1 yv9 of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass frb0785 ngkco of planet A. If planerb0n7f5o 8ckg t A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radiu+;4gupr xc 6mss r) about a sphericalp6xgsr 4+c; um planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same o* h,.ep1uhj 0d 8jyhzgrbit. Compare the two satell,h*y jd pjehgz8.0u1h ite's speeds.

  A person is standing on a scale in an elevatyjjp4l 1 9 t+-9cni*,vfkgn xhor accelerating downward. Compare the reading on the scale to the person's true we+fk*14 n jn9 x9yhcl i,vptgj-ight.

  Who was the first person to realize that the plane ahx sa4gdy4h1w.i k17ts move in elliptical paths around d skh 1xw4hgy.147aiathe Sun?

  The speed of Halley's Comet, while traveling in its ellipti*xpeju9. d9akcal orbit around the Sunkd*.xpaj99 ue ,

  Let the average orbitaltu8 as8j :-qq)xa3rfpx9)c0h kkhx x1 radius of a planet be R. Let the orbital period be T. What quantity is constant forc3 9rhu)8sx )q0qfkk 1tpx -aa 8xhxj: all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromedao2zxg,xrhi bfi-x a80ebiq *:s s6.l., with the same orbital diameter as the8xqbr l ,z26hi*ix:- bsf ga0ei.s .xo 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 defi+tz25s p;exmcned as one "astronomical unit" (AU). An asteroid orbits the Sun in one-thir+ tpx esmz2;5cd of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.dyduhe*x29w nrxort5o a,n:-io9(3 f

  List the four fundamental forces in nature.njuh *+he)l31tw( asu -o.lq-do/xxe

  An object moves with aul5jo.,g,) hokz av)y constant speed of 30 m/s on a circular track of radius 150 m. What is thekla) o,5 zhu) oyvgj., acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. Whav)u w 0hq(lvc8t is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchangv(w hc0quv 8l)ed.)

  What is the centripetal acceleration of a point on the perimeter of a bicyclei -bx:1m n h5sk l1fj;+)tgbrr wheel of diameter 70 cm when the bike is moving 8.0 m/s x 5t+lbi;jb kg1 rfr:hms-)1n?

  A point on a wheel rotating at 5.00 rev/s is locatryloehr:u9d rfl 6f6 x/)+x0fed 0.200 m from the axis. What is fdu l/x 0ry9xl6r6+ff h:e)ro the centripetal acceleration?

  How many revolutions per minute must a circular, rotating space stav5em/t 3e3k yayd)(,t zwt )uwtion of radius 1000 m rotate to pt) tvemk3 wey5 ,wd)tuy(/ z3aroduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass az ki5;bgogc3x,t, ;cof 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcyc x5,ccoggz ;3ai kt;b,le?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whip( 0xon pgsgr8;9/q wu3vquu9, qp w)nrled 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 string is not to breau,v(;)ru8 3 9q /qx0owp npwgpnsug9qk?

  A stone, of mass m, is attachedb8qgq-)tn7b l to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the t)7qg bq n-b8ltension 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 strong string and wh*p:pesv16 1docx j5iqirled in a vertical circle of radius r. At the exact bottom of:poxd qpi5c 6s1jv *1e 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 exper 43rs)u 5 5jggqpon3sj)ihm)ov*m. eykpv+ z7iences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane 3ij))oq gvyjr gmk745+ v he)z*5opups3sn.m is flying?

  A pilot makes an outside vnxsi 41ia qs5o3p9,t (ur yrz1ertical loop (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 wit(a9 isrrz t5u,o 1 3inpyxs14qh only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is abm xom6 u2a1 kwpf651vhr-nqv.out seven times his weight. What is the minimum radius of curvature that a jet plu1xvpk.m216fh 65 awqrm v-onane'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 curve wxdqn0t, ek 7*iith the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume *70n ,qtdekixthe same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a c8x)9m y-hdsh flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided b) xhsd8-mych9 y friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 5g6e;(w bxp 4 msqke2p+tn)5da 0 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 the turna egbxn2 td)p(5w+4q sep6km ;?

  A car is moving with 9zvm t+c,bhgq (0jfi) a constant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the cu+)v9c(fqh gjmi0zb,t rve if the car is to stay on the road?

  What minimum banking angle is requir le 3v1wl(aci4ed for an Olympic bobsled to negotiate a 100-m radius turn at ali4e1w3lvc (35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at 3, e8m*dthoky syxw*8a $45^{\circ}$ 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 angl1(vp5kr 8n7snpw e( rqe of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i39mt3ks l beh8gku y3:s 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 circ;hxynkq9b/q 7 le of radius 0.500 7 ybxk9qhqn ;/
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 m ( vf,hyn/) ahv.9 cgt0.fg qdbo-z5ka uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of rkghvz5o,9t 0n.b-.fhfv a g d(my/) cqadius 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 consi+76)voufu xc no4vko 1sts 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 gravitation(e2qqfxao k uh.jt4 :/al force on a 70-kg person standing on the Earth, due to the o4 f.qt/a(e:x2hq uk jMoon? The 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 hmx)uo wk f. nb5 (a4w8ek,8lhmasses are moved to half of their initial distance, wxh8a)k, 8 nlbw kow(he4fmu5.hat is the gravitational attractive force?

  For a spacecraft going from the Earth toward th f152gqijmof/ e Sun, at what distance from the Earth will the gravitational forces due to the Sun and qom1 ji25fg/fthe 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 jz): eserr2 7:pp-vkc36gcp yis $7.4 \times 10^{22} \; kg$ 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 .fl(9 irarcx y,e0d-gEarth equal to the radius of the Earth. What is her accelerayal0f.c- x, (dreir9g tion due to gravity?

  The radius of the Earth is R.b vc:o9wz7ff4 At what distance above the Earth's surface will the acce 4f zcv9w:b7foleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dist+0ru c)u7k/ hj6vplgeance above its surface equal to 3 times the radius of Mars. The accelg6rlj0u+) h7v eu/ kcperation of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gragf77o4dwkj upj: ,b(v4ps6 dr vity is u:74g kjpbdw po6r s,(vdfj74 $32 \; m/s^2$. 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 rs4nk- j(mqumndb1: (s adius r. If the object(1n4 um bksn:s-qmjd( is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weighdlhpla 3/ 7-qlt of a 100-kg person change when he goes from sead-/ lalhlp7q 3 level to an altitude 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 is at a point 3r above the72lm afn g at.n9lmo9h4l p84f Earth's surfa8.79lfgtll4o9 pa f man24nmhce. What is the satellite's weight?

  A spherically symmetric planet hasap 3.dxs tz39d four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 .d 9ap t3x3zsdN on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, wiqbxrkk)g zr.gbf )j,fs17*s 1th the Earth between the Moon and the Sun. *s xj)k1 rf gqs,gkbb1)7zr.f 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 toi7efks/ u:od + 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 the Earth jsch0 r080u zs(i.e., it just skims the surface of ths8 hz0jsc0ur0e 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 skims theog8w1ltca(f.8jp 4h1ma ne2g surface of thwf8p1eolaj1ghg(c4a t n2 8.me Earth). How long does 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 the surface of the Earth. It is s *.v )fpc8m zq4e,vqkobser4* ,fm)s kvcqp zve.8qved 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, hwi v/fmg ;32qv)n vcc :+q6x) dq)npiias 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 Jupitt*x1-fb /bgwo er orbits 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 o(q kik55x a.lradius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B 5kx5a ki(q.ol to complete an orbit?

  The planet Jupiter is sg f oqx 10 +o6s3v1z,.ptcc(ro5igbw$7.78 \times 10^{11} \; m$ 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 u y e*y7;4guecorbit the Sun once. What is the average distance from Jupiter to the Sun uey4*ycue ;g7? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)