Is it possible for an object moviau:g*e t*1d oong with a constant speed to accelerate? Explainuo *dteo:g1a* .

  Consider a particle moving withy7m rs07tp7j s89nkpk constant speed such that its acceleration of constant magnitude is always perpendicular to itsjn 9tms8kpkr 7py77 0s velocity.

  An object moves in a circular path atg z,enj ,ymost0 25z, spgva*7 a constant speed. Compare the direction of tz, g5 y,vjeopnm7g*,szs0a2 the object's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the k 0 ,nw+qxoft* 43rgsmacceleration irkt*wsnxog 4+f 0mq, 3s

  Consider a particle moving with constant speed such that its ac:ce, n b 2efa1g5yj3zravi3v 8celeration of constant magnitude ez f8r vjb 13iy vea2:n3cag,5is always perpendicular to its velocity.

  What type of acceleration does an object moving wizq : t0.deoit 9z1tu-dth constant speed in a circular path exper- uz9 de1: tq0.ttozidience?

  What force is needed to make an object move in a circleq szg*t 9nherjk6+89k?

  When an object experiences uniform circular motion, the direction of the ne9i jt rc-q8c:vopgl1 *t forc:t coj9 cq-pvl1ir 8g*e is

  A roller coaster car is on a track that formsgyaa5i .(vex 3 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 for its centripetal acceleration at this point?exvy g3a( .a5i

  A roller coaster car (mass = M) is on a track that forms a circular loomb2f:i: 8t pvwhtq3.(jawo.rp (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 tpmtf vht2w (. ib8oq3.jw:ra:hat point?

  A pilot executes a vertical dive then follows q n*pg.h) noy4a semi-circular arc until it is going*.4qgyo)n nhp straight up. Just as the 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 o1yrlas-da m )0 .rg2asijg+12 tc(/l pkcod2yf 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 constanj(-m d7 w fdvo z* :i58c*y5ikarrtf4dt speed v. Then it goes around the same curve at half of the original speed. What is the tcv5*r*i i(5 wf oy7jdr4f: -dmk8zadcentripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a cu;ecov7m3 w; :m-8ty7/psruvjco +wt qvtd r:7 rve 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 as it goes around the second curve, compared 7s 7t +j3-vw;my:m8ct :r/;ruc ovde 7votwqp to the first?

  A car of mass m goes around a banked curve of radius wv3img63e1 za b(8adjr with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component ofzm6aw3 3db 8(i1e vajg 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 same angle, bzd.d,foz7*/rcu t wj1ut one has twice the radius of the other. The safe speed (no friction needed to stay on the rjr, dwct ozz/f1. *7duun) 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 bobsled track is not c*rr1k4;t 9f b:vynoep q2r8nt0t9j kconstant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "cli:rv2n0rt *tkb99e 14ytp r8q;kconf jmb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an o nr3rfoj9 9 jpr13ok;sbject moving around a circular path to have both centripetal and tangent3r1fjo9kn;3pr js 9orial acceleration?

  The gravitational force between two objects is proportional t (+8j9ent uvu1g m4q1z)c dyngo

  The gravitational force bet *ad6lbq0yo:v ween two objects is inversely proportional to

  Two objects attract each 7jp7 41buth zgother gravitationally. If the distance between their centers is cut in half, the gravitath 14zbt7 7pgjuional force

  Two objects, with maspf.h,xrwlsc3 *sc6ckl 0 cb0 -ses $m_{1}$ 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 ma o mioina385;nsses $m_{1}$ 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 undb ae)k pq9isa9z,b/, x.h,gxiversal gravitation.

  Compared to its mass on the Earth, the mass of an object 2 (jhf3;4z2ctytqi/ls-o26wlx(r k sdgto1won the Moon is

  The acceleration of gravity on the Moon is oneu)3+y 98pfyp lbaomv6ub 1e mob+o ,z3-sixth what it is on Earth. An object ofyv186eb), u 3 olpm mua+y9bzo+p3obf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocke jpq2 o8ym+;alt's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull orai2+upk 93yhz2 icp,f Earth's gravitr3cpu, iap ih 29yz+2ky?

  Suppose a satellite w.oidq 1d1 )qh 5fis:rwjxp;* jere orbiting the Earth just above the surface. What is its centripjd:*rpx11jq)wihi.f 5s dq;o etal acceleration?

  A hypothetical planet il) +et)oxya,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 gravi o+i, )la)xetyty at the Earth?

  The acceleration of gravity on the Moon is oki -pvog3 5xwhw9dud uof(0 ;/ne-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. Whavihp/d oo 5(9 gf3 -dkuwxuw;0t is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twiv dueakl(; -ty+li6b8ce the radius of planet A. If planet A has mass m, what is the mass oivk-b;+ ea8dl6u yt(lf planet B?

  Two planets have thev/83 guagkl/ j same surface gravity, but planet B has twice the mass of planetlggv 8a//kj 3u A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circovsxkb;,;bw w fgnq+x . uh)8raf99( :iraz/j ular orbit (radius r) about a spherical planet (mass M).)8ww(qx+jo9;hrv nibk:zf ar ab,u.x f9/s ; g Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbit. bm p2gt+/*p ksCompare the two satellite's speeds.2ktbm+ /g* spp

  A person is standing on a scale in aocj5l7 vs ne/(n elevator accelerating downward. Compare the rea5sn(/lo7 cv ejding on the scale to the person's true weight.

  Who was the first person0h*yh kg),xeut( vo9l2msc)81 v b crb to realize that the planets move in elliptical paths ar)o,vs( he10mhb bu8r vcgt*l c92 k)xyound the Sun?

  The speed of Halley's Comet, wz/qz ml3re zz ,xq)1-bhile traveling in its elliptical orbit around the l zzrzq)q3 z/1 mx,b-eSun,

  Let the average orbital radvlte+ -:zla-qr0h0 pif y:t 6sbyz r-(ius of a planet be R. Let the orbital period be T. What quaa: i:y0zzq lr(svp htyl+b ft-06- -erntity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit aroundgxzv hx+ j;a* r)92gip a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, whax* vx+r9hai; )2gj zpgt 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 definek0oiv-(k i wn9p 9wmv-d as one "astronomical unit" (AU). An asteroid orbits the Suw(i nvm9-9iw-opv0 k kn in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.r.q/nnevg 4(: quz yh7

  List the four fundamental * o iwk3sp9c-5ssnyik+,h z c/forces in nature.

  An object moves with a consta +ar-(q pgz)5i5 jegcxnt speed of 30 m/s on a circular track of radius 150 m. What is the acc55j ig) -gc+ e(rxazqpeleration of the object?

  The maximum speed around a level curve is 30.0 kne 8;v7u*v3 lit dn0zcm/h. What is the maximum speed around a curve with twice the radius?lcutd* 7 30z8vein;v n (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter z( qnq 8k*gi*pio:*xcj5y+0;fksypyof a bicycle wheel of diameter 70 cm when the bike i*k iszqp *gqnyyk +cpfyxo ;ij50: 8(*s moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from 82yva kh.b5a8z)0nq;psi rrqrq +-dcthe axis. What is the centripetal yra0+rhcqda;)i psv q2n8r. - 85qzbkacceleration?

  How many revolutions per minute must a circular, rotating space kuup/c 78ebo0jd7. adstation of radius 1000 m rotate to produce an artificial gravityp.eukjaddu7 7 8 cb0o/ of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.2lk-x8b bx1av 7 m radius turn at 96.5 k2a -1vlxkb8b xm/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to theb07x jjdurwx6 /)mr( jj:hx1vv9y/ee end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand wdx6u/7x(vyr jxjmvr :/b)eje10j9 h 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 strin zsej1n,0a c38oyfc7lg and whirled in a vertical circle of radius r. At the exact top of the path the tension in the stringosyc7ac0n8lz je31f , 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 aqxd5c+ 5btykxom2am4 ,,fnj 8 u a(8zlnd whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 time(82kx ,m4y+,ao lxb5d zqmtncf 5a8j us the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an accelerr z2z h5p;dug7ation of 4g when pulling out of the dive. What is the radius of curvature of the loop in whzp zd2rg;7u5hich the plane is flying?

  A pilot makes an outside vertical loop (in2*jog+u 7 gf,4 hjvka t7stef*u 8+ckn which the center of the loop is beneath him) of radius 3200 m. At the top of his loop h7sft+n+o,u*2 gv 8 chjj*kek4ft a7g ue 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 his weight. What is b*qs -l:uq,zpa b3z n-the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a spequ ls:zp- nq ,a*zb3-bed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with thi/iw8r3y:hv oe tires on the verge of slipping. How fast can this car round a second curve of rady o3hvi/8wri:ius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve o8c m mow ie 8k-s.dskdap)kkm73cq3/(f radius 50 m with a speed of 20 m/s. The centripetal force provid p.8k am 3 simekmck/o73ws)8cd(kq-ded by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of rago 1fur ,vn,nk+c3sd5bk6e5cdius 50 m at a speed of 14 m/s. What must be the minimum coefficient kkv, cesu, g1on+bd 355crfn6of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speem+xqq8 1,mw4/iqj(dkx2tp je: m eih: d 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 curve if the car is to stay on ti2kt,qj41 :+hdqq mwe8mxi( xj /mep:he road?

  What minimum banking angle is required forf s mzp/dyu6t y5z;*f) an Olympic bobsled to negotiate a 100-m radius turn at 35 ;fp/ z)5f6m yzdu*s ytm/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run isds f*(*hzorqud3)h:keshn -c ( m:jd+ banked 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 radi)p5 4 qmb+dryrus 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedt sm9) 97qs+pp wnf tnva;8f cy46)9qlvx4aq v 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 4n ixnea--lf9i 7n1cauniformly in a horizontal circle of radiu4 inei acan917fnx-l- s 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 ay9c*un 369-aj ka40shfk h pstccelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track 3sjtc f4ysa-90n p hkk6h*u9aof 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 mas,pt5f berc: 7ys $1.67 \times 10^{-27} \; kg$ 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/ yqq/(s;cs 82rygrmozki ),b on a 70-kg person standing on the Earth, due to th rgksrc(,i /)s2; /8zmyq oyqbe Moon? 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 cbfe7svy )jsy.0( uj5y(v5o abetween two masses is F. If the masses are moved to half of their y.7 cj us(55y j)v0eof sav(ybinitial distance, what is the gravitational attractive force?

  For a spacecraft going fromp va+.l(gp*/rj yu /ys the Earth toward the Sun, at what distance from the Ear/lap.y*u j/ p(rygs+ vth 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 iswoysi30lr;7/k h6dnx qqn4 o7 $7.4 \times 10^{22} \; kg$ 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 t.;iv (0ggnqpfc;v/33 dbyk m xhe Earth equal to the radius o0g/p iv qcm;kxfg 3nb.dv(; y3f the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will g(1c vrmtw5i4 the acceleration of gravitygc1rti wv4(5m be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times the xx6 deu u*d+vstmd/3uy 66/d(dw5mfr radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfacv*x 6ud +utwdm/yud 5/dmrsxfe6(6 d3e of Mars, is

  At a distance of 14000 km from some planet's center, the accelerationvpgg82j3 mtg d9x ol6) of gravityox6dgm38g)9gpjvt l 2 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 thox /ozcu(5bd2f(cm a+e Earth. The Earth has radius r. If the object is raised to a height of 3r ab cozm5a(d(+2/oxcu f bove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person ch31u 9ao(7,e *iekm/a eddbnodange when he goes from sea level kam 1u ,eedneo 37bid*a/od9( to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r9ck x, x . kvinc,leo+vl25lt3. A satellite of mass 100 kg is at a point 3r above the Earth's surface. Wvix e,32+nl.otkl cl5kx v ,9chat is the satellite's weight?

  A spherically symmetric planetfyft h bu1+yl 304fj7o has four times the Earth's mass and twice its radius. If 0fb74j hf1lt oyyuf+3a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Eartmk/2a)d/uo-rko- e sgh, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon 2o) das-r/m/ ekkou- ghas 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 tra srofre 7 c3t8jn3ar6-nsported 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 6dt vry 1h4dh,*/8i cw fa9zhzhlj ;+sabout the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earf l 4hi89w/ ;ahzt1s ddy+,hv6rhzc j*th is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low0 wdfqz 8(4pfb circular orbit about the Earth (i.e., it just skims the surface of p d(4zwqb 8f0fthe 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 surfaces2+qeed wac x ln6)1m: of the Earth. It is observed to have a period of 89 min. What is the mass of tw1)ds2 c6aqenxe+:m lhe Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbitaluk -6aq;yxtpf :0lyg* 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 Jup volo57)m grhlxq2 .q3iter 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 ibh5 .tjncw9v8zx w7 ;u4 1aidrn nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days.w7w1 4un85hbj ic9 vxdr; azt to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is okw:+i*dgs9/v 4o d op3f*un3 :bnjxv $7.78 \times 10^{11} \; m$ 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 Sun q me3:u;pdd)ts: g,efonce. What is the average distance from Jupiter to the Sun? (The distance from the Earu3 sd : ft),;pemeqg:dth to the Sun is $1.5 \times 10^{11} \; m$.)