Is it possible for an object moving with a const .svkq (:jltn2vt+mp: ant speed to accelerate? Explai:+2pqsn kv vl(.t:mt jn.

  Consider a particle moving with constant speedga +* tn abb5mee1q:*d;ftni7s tc h4, such that its acceleration of constant magnitude is alwa4f7s dq a*m1:eg;+c e,int5n bathb*tys perpendicular to its velocity.

  An object moves in a circular path at a constantl7(u0 bna f3wx speed. Compare the direction of the object's n3xba wf70u (lvelocity and acceleration vectors.

  When an object experiences;9v; g*cjc;tb lj;h/rvyt 2kock .so1 uniform circular motion, the direction of the acceleoyo9;k 1 /b2*kt;lvtj .vchcg j ;r;scration is

  Consider a particle moving with constant speed such that its acceler9 pq.dz)9kuzqf7r q7z;i vk2yation of constqfp7.rd zi ky z;qq9)ukv z297ant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object moving with cw6ulg 7;ds ee;onstant speed in a circular path w6lde7se; ;ug experience?

  What force is needed to make an o,y;x*dc(m*r.xd 1u hfwsf ;mp bject move in a circle?

  When an object experiencq6(l9qqd5bx,k 3jql g es uniform circular motion, the direction of the net forc3l 5jl qkx,dqqqbg69(e is

  A roller coaster car is on a trac42n v du-z:rvhk that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the lo- r2dv:hzvn4uop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass =5g399 k hurnsn M) is on a track that forms a circular loop (radius = r) in the vertin9h935k gnusr cal 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 point?

  A pilot executes a vertical dive then follows a semcv6cmym lr /fhr:re9qd ka5b 1x k05.;i-circular arc until it is going straight up. Just as the plane is at :m ar/ y. hx0;1qvcd9f bkre5l 6krcm5its 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 radiusg+ /6;f4( bmtgln46 hgkpq+ zz nlrx1r $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a f4-h3wpp o a(q1leu fc4tfmz8 tz2-k5curve of radius r at a constant speed v. Then it goes around the same curve at half of tp-tl omqh8(4 cak1z4253pfw -fz tue fhe original speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it0t2f+7pp fgxli g,z 2kkneuw 8n gp196 goes around a curve of radius 2r akkwnp96 g82lf0gtnf,pig+u2p e 17zxt speed 2v. What is the 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 curve of radius r with spglj s p.,h2rm/pgo 6 m 95,iaw:ssxkj/eed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component o , 9w6i/sg,2xgskpjr.a /:shmjmp l5of 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 sami0ms2-z rli(s e angle, but one has twice the radius of the other. The safe speed -2 (izisr0lms(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 Olympic 8j4gi5fg/4 wce( ccgybobsled track is not constant, but increases upwy5cgi( e8 wjcg/c4gf4 ard 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 around .k jf(:q5+ dkf0doluu; -b -;jj3bedt:idweoa circular path to have both centripetal and ulej.:3qj -w+fk-; j;uek5dt: dfb dbo0i(do tangential acceleration?

  The gravitational force betweenzt;mo 8udsg 83*kajj j :hnq2, two objects is proportional to

  The gravitational force between two objects is inversely proportional t.a8dky/gnk g *o

  Two objects attract each other gravitationally. If the distance betweua5y0+ x we;mr) (wqjuen their centers is cut in half, the gravitatiu5(qrxwju0+ )y ; amweonal force

  Two objects, with massesu:-)eiz cl s/b $m_{1}$ 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 masse4e+ujn s.4ebhywg0o o-fas9( 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 78en f5a.0qig5v +qw 4df iyei7a2fa ouniversal gravitation.

  Compared to its mass on the Earth, the mass of anm5y qpc:(d 2.devy:eyd t+(c t object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earh(g4.t-u: by z*qj rkwgme :,bth. An object of gr:hw*,qe-y. 4 z: bj( bgmuktmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves awayhf;19 v. ndqx-ljjh 4 fv.xv)ub dm83c from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull of Ewtmzu;, v;4godk.+pnartu4 v;t+owgk p,m;nd.zh's gravity?

  Suppose a satellite were orbiting the Earth just ab2.s1 o/zv qcimove the surface. What is its centripzsmc2.qv1/o ietal acceleration?

  A hypothetical planet has a mass of half that of the Earthgh*,0 kev8 de0vvo6xg )k d,un and a radius of twice that of the Earth. What is the acceleration due to gravity on the planetdxok)u6devv,0* v,nh k8eg g0 in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the M:3d(x*2 *jlcn w: lt2l:ww0 vmerktn noon is one-sixth what it is on Earth. The radius of r*j:d0k:nlnm 23nwtxwew2lvc : t(*l the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravityiuj9x mqi3 ;v), but planet B has twice the radius of planet A )um v3i;j9qix. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of p1 ofp( b uy;c(srd.q4flanet A. If planet A has rob1(;4.qf udf (p sycradius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radi *mw3q u,2nglrus r) about a spherical planet (u3n g2w*,ml rqmass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mam81fp5x gb l+xss of satellite B, and rotates in the same orbit. Compare the two satellite's spe1+5m x8p glxfbeds.

  A person is standing on a scale in an elevator acceleratzax 02p +theduweayc+r) k, jni t5v2+h. u9:ning downward. Compare the reading on the scah e )0p9n:jer u+x.w+25t,dna+uhkat v 2 yiczle to the person's true weight.

  Who was the first person to realize that the planets move in elliptical-b ji27-(bx.oa3mw.ss pho 2pswrk8 tha 8/ ze paths arotwh.o2a-impa k(os wsex.s27pb- 88zr h3bj/ und the Sun?

  The speed of Halley's Comec47js/ mfxpo3 t, while traveling in its elliptical orbit around the Sun,oc7xsj p3m4 f/

  Let the average orbitarjih qr l;:.4ql radius of a planet be R. Let the orbital period be T. What quantity is constant for all planets orbitin4h jrrq:; .iqlg the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromed;(ds-nx3-prkw zt 8dwfs e m,: 4;:etnsf)shha, with the same orbital diameter as-ndsw3wr-), fsxet(h4t8:d;p : hes ;z fk mns 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 thexj0(vj5s1dnumff t;5 ; au.hl Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average f;m f1du;hvjntl5 j u5a0. xs(distance from the Sun?

State Kepler's laws.6 jpqjqw2n;a(

  List the four fundamental forces wn*,ua1q ,s fmin nature.

  An object moves with a constant speeu2ai )l8ak;p:sko z.bd of 30 m/s on a circular track of radius 150 m. What is the acceleration of thk2:oukb)s.8ila; apz e object?

  The maximum speed arou5uh q)s -sf2)/ht:j3qxwc gwind a level curve is 30.0 km/h. What is the maximum speed around a curve w5:3w wch)jqgqi2 / u)-xtshfsith twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point83o,g c,fx,i:8kva vkj t yol: on the perimeter of a bicycle wheel of diameter 70 cm when tot x:,vfk8i c:3 vl,kg oa,y8jhe bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axisu06cqkiu9 o i9. What is the centripetal acceleratio9690iicu uo qkn?

  How many revolutions per minute must a circular, rotating space stationd6+fqpc9o+ h y5njx 0j of radius 1000 m rotate to produce an artificial gravity q+n cjpdo+9h y5f60xj of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. Itp ju+auy )n41hbd+88 gm gimz9 goes around a 13.7 m radius turn at 96.5 km/h. What i)d+mg19u8hb + 8m4 izpy jaugns the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0h i- s0 nhl(e.*teew/d-m string. The system is whirled in a horizontal se-.(e0hn t/e iw* dhlcircular 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 break?

  A stone, of mass m, is attached to a strong string and whirled iqbs8e.oc.0qr n 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 speersc80q b.oeq .d at this point is given by

  A stone, of mass m, is attached to a strong string and exwm-g/mmh.jof.4q3/ a st4m 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 this point is ./m.4qgt-em3f hwsj/ aomx4m given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out oum475 n)gmxnz7,zd7ama. h(t7n c lckf the dive. What is the radius of curvature of the loop in which the plane is flying nn,7 7um k.gmzac5xntl77)z md(a4hc?

  A pilot makes an outside vertical loop (in which the center of thes2d t*-4yzs fxbwz; 2jc 1;zwx 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 normal xwss ;w -ycz4fjb2d x1tz;2*zweight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weigh u;)qr btcdzv:( m6)krt. What is the minimum radius of curvature that a jet plane's pilot, pulling o)( )r6cvz:tmdqk br; uut of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds .tvm m.c:t8y hukx;u3an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curc;u8h. t.uym:xk m3vt ve 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 cne qo pro45.mdj67n+vay((hxurve of radius 50 m with a speed of 20 m/s. The centripetal forprq (4hnxomv(5yj n+a7 6o ed.ce 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 bf3(w7fdmwst w0 7rc(y6v9 ha at a speed of 14 m/s. What must be the minimcb y3(9mt(hw fdw0srfa 776wvum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant sj w; -mw bujmp7722dzipeed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimumizw;bp m mwjud-7j722 radius of the curve if the car is to stay on the road?

  What minimum banking angle is z *r6yi mpj/n5tjk(kxxj+f;; required for an Olympic bobsled to negotiate a 100-m r x r;56kp*(jy; mt+j ij/xzkfnadius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked at a 4+vars-8r r) p rk3git$45^{\circ}$ 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 5 vj2h/ ckuak(an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m xv42 wr pw66-v iy0heris 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 horoo y.-bf*vf/nfw bk3/izontal circle obf/o*v/wf.3 ykn -fbo 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, a race car accelerates at a unh 372db:qwb*/i)o cg w:oyiaoiform rate to a speeo2q:3wiy:) og7baw h icb /d*od 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 a proton.cxdz*+i 95+w l(ridopmui a 7 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 stanf8(2/xw z0zg+xil ipeding on the Earth, due to the Moon? The mass of the Moon f0ixw2 x(p/ziz8le +gis $7.36 \times 10^{22} \; kg$ 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 arn(6ll 6f zd8d-f go;ere moved tnd - ordl8z elfgf6;(6o half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earthz 0 kyaj2fuxjn bx)r (2 f.a)r.q+(kuf toward the Sun, at what distance from the Earth will theuubj)y02rfaxn+fa)z f2(( qx . rkjk. 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 yzx) 1+bwz)vq $7.4 \times 10^{22} \; kg$ 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 disw1))jd qum/i o434vvb ugwek3tance above the Earth equal to the radius of the Earth. What is her ac/ k1)we 4m4uvb uwi3dv3g )joqceleration due to gravity?

  The radius of the Earthcr qs8y/d0q z+ is R. At what distance above the Earth's surface will the acceleration /d8yrqcs+q0 zof gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distan4bb j.tsvp x;7ce above its surface equal to 3 times the radius of Mars. The acceleration of gravitysjbxbv4t ; .p7 of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km hci(d8 ms-()qbc:ybf from some planet's center, the acceleration of gravity (dfbbqc8hmy (s-c) i: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 ti7mlw(/snqjp 5b(+ ih he surface of the Earth. The Earth has radius r. If the object is raised to57l+b iw( sjm(hn/iq p a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg persot6+qbk3 r:fkw a- qihr;b2ra1n change when he goes from sea level to an altitude of 5000 m? (T+fhb3 r2rki;r1twk: qa6 b-aq he mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of ma)i vj 3ts8 6ujl/4mtucss 100 kg is at a point 3r above the Earth's surface. What is tmv) tl8t 6 cs/uu4ij3jhe satellite's weight?

  A spherically symmetric pln h tn zahl95q;xjcx;;g3* *boanet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 1 zxhhacq; jl3nbn9x*g5t; o;*2 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Eafo/8m( ydvw7 nhe +e,brth, and Sun all lie on the same line, with the Earth between the Mfy+ e b7hvn,/ oe8md(woon 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 theonm07 i4wvw3c 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 eu: ifg,, ktw1about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean i egfu1,w:k,t radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., ittgrl:(y0ng+oht l-y1t6 7 bnd just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the g6gy 7-tl1tt n:+ hrbyn0l (doEarth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circularav w9s0jwru,/te s1 n3 orbit 230 km above the surface of the Earth. It is observed to0j,ns 3eau9wvsr/t1w 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 oz /p5nzlwp i yt9b;/eh+d1 ,juf $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a ra w1c 0oy;ape-z/em4qcdius 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 hal/+ izdtfm:-lk 0u3 z;gbld,zs orbital radius r, and moon B has orbital radiuumfdk:-bzil;td3g z z,l /l 0+s 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter izvi3 4ljjh.3is $7.78 \times 10^{11} \; m$ 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 jq3.i w6x(86ndu v6zzu0rycj Sun once. What is the average distance from Jupiter to the Sun? (The distanw( 3.xuyj6i6qv86urz 0dn czjce from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)