Is it possible for an object moving with a constant speed to accelerate? Exkgqswa:;jkld d22 -jbr i ;c..plain: 2k l rksc2jwad.i;jqb.;-dg.

  Consider a particle moving with constant speed such that its acc 1llyczi . ffv3+8r-gp)w+4pdytps r/ eleration of constant magnitude is always peyspcr/i)y-v4p g.zfd1p+t+ fr83lwl rpendicular to its velocity.

  An object moves in a circular p 8xmmld8d: 2tiath at a constant speed. Compare the direction of the object's velocity and acceleration vector:m m8t xd2di8ls.

  When an object experiences-7zn- f3 johpu uniform circular motion, the direction of the acceleration izfn- pu 7oh3j-s

  Consider a particle moving with constant speed such that its accelert783fnby6baxvh(zi kf 8e :q-ation of constant magnitude is always perpendiculay8k7 (e8abx z hvi-fqf:bt3n6r to its velocity.

  What type of acceleration does an object moving with constant sp*s pd dz/)w+tebg, e9eeed in a circular path experience? e9pwdbts)eg d,*z+ /e

  What force is needed to make anyp4 ;byzzove:a +uo 987h; adc object move in a circle?

  When an object experiences un1f bqew, z 8ks3ly0ko5iform circular motion, the direction of the net for5w ok zl8bef0 k3s,yq1ce is

  A roller coaster car is on a track that forms a circular loop3eo v0jms:rx*b x9p7s s ntc(4qg+h;p 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 jbt xp:xo*4q;+s0c3 re shn7 svp9 gm(for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that fo 6 hafxi8vsx - -()vxe/humjiu-3ft6yrms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the trac( yi3--e )xuv6/8xhv ta-ufh j mix6sfk 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 cop6 8;,-- lq5pnbl;xeeo;s 5*lff d/ urfpljarc until it is going straight up. Just as the plane is at its lowest 6lu;j5 5 soedplx/l8r* f;feq;nlpo cb-,- pfpoint, 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 radius mv-tsslr+th5 hukd:bh +)l 95$r$ 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 constantjju-0 )(mcdm c speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force oucm0cm -)jd j(n 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 it g( hrphfjsgv w)()d3n8oes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as r d(v)psn8gwf( hj) h3it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius cn -36i 7.jt vp8mqwfhr with speed v. If the road is frictionless due to ice, the car can still negotiate iq- 8 h.cm63wjvn7pftthe 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 same ang.fl p) 0ejn4dlld--iy;hm. mole, 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 lmd-on l)- 4m0jfpe dli. .;yhv. What is the safe speed on the larger radius curve?

  The banking angle in a turn on thed+ k0(; )m fur: sk:tho-ezjpw Olympic bobsled track is not constant, but increases upward from the ho;-h m swrek( :zu+o:j)kdf0tprizontal. 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 a circular path to h8 l 6ty;kqkivxy5,c6qave both centripetal and tangenti8yv ;iyq tq66 ,clkx5kal acceleration?

  The gravitational force between two objects is proportiont,zv;um)(mo pj j+eq9rw0 l6 nal to

  The gravitational force between two objects is inverseugkqk4*ku1 mag2i8*nrpb, + sly proportional to

  Two objects attract each other gravitationally. If the distwuq, k09)b e;,uh et +dg(c1k3vo ngrwance between their centers)wq 1 3ub+g0 oc;ek tg,denukh,( 9wrv is cut in half, the gravitational force

  Two objects, with massemf(7)8t s vpnis $m_{1}$ 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 mas /xm-9w x8 wrj*asx,mi hbjp m/:n7: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 universal gravitatia4;7n obo-eqa on.

  Compared to its mass on the Earth, the mass of an object on the Moonofle d5 +0zj1 ;z-voxlf 6g.t*q* xwkn is

  The acceleration of gravity on the Moon i17uhpkq1lp s5s one-sixth what it is on Earth. An obj7p shl u1q51pkect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocd2t d7rv- f,(e/m8tcy c+buh yket's weight

  A spaceship is traveling to the 41wgs4fan cx )Moon. At what point is it beyond the pull of Earth's grav4g4c nw x)f1asity?

  Suppose a satellite were orbiting the Earth rpn*( ::ef8zz 8ynw(pvd ux, djust above the surface. What is its centripetal acceleratior: :z8pnp( uv*xd,zdf w8y ne(n?

  A hypothetical planet has a mass of half that of the Earth and a radius of twk*r kz;k 9ddql o:jg((ice thar zgk ;( ddk:9q(o*kjlt of the Earth. What is the acceleration due 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-s/wysoispo 5j+ a(p;l9ixth what it is on Earth. The radius of the Moon is one-fi/ aswjo5+y9l(pps o ;ourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gy8cgr -yrzh k2 6me0u9ravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planetryr 9yz6eguc k2h 08-m B?

  Two planets have the same surface gravity, 5bw ta+a2x50ezr :qyw but planet B has twice the mass of planet A+a zyr055 wtb2e wxa:q. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radiu7s/pt( 7bsx0dw )rarfles2e )s r) about a spherical planet (mass M). Whic df2rss7 pw/lx(era7 )s0)beth expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rota*i d;w,uri 6iuc(.xx w;+uug4jdf)ixtes in the same orbit. Compare the two satellite's speed i(r wx,fu du;)cixjii64 +.;uudxw*gs.

  A person is standing on a scale in an elevator accelerating dosg qs;(ii+f( swnward. Compare the reading on the scale to the person's tru(isgssqif;(+ e weight.

  Who was the first person to realize that the planets move in elliptical c mxbxx 7wu/:5paths around 7x5wxu:c/m x bthe Sun?

  The speed of Halley's Comet, z(5hz(n8 d7) ,ga68z gqqfkqsm j(+yfr,lsp p while traveling in its elliptical orbit around the Su6qnr)8g,yhd pms5aq p lz(+z fg7(jk qsf, z8(n,

  Let the average orbital radius of a planet be R. Let the orbital perd6+tpiy f0a d6d:o(cviod be T. What quantity is constant for all plat p6dd6yd:+ico ( 0afvnets orbiting the Sun?

  A planet is discovered to orbit around a star in the gaeotz:/o wjb-4z76m9ryw fvy/ laxy Andromeda, with the same orbital diameter as the Earth around ouryy/9j6vzbfz/r7e m w :tw4oo- 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 defined as onebc1 p4.m5ln gn "astronomical unit" (AU). An asteroid orbits the Sun in one-thirdg51 cnpmbl n4. of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. fljrlnil2zl/he.e zz /)4u,*,4r v hc

  List the four fundamental forces -wwv(na+-ns s c2v t.lin nature.

  An object moves with a constant speed of 30 m/s on a circular tracvhys bw)5cfec73)dt 3 k of radius 150 m. What is the acceleration eswvf3c t37bhy)c )5dof the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum;lc:wkmd,yz xx5b7 /m speed around a curve with twice the radius? c75wm,y/zl:;mbd kxx (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point em ,9iel :n(zdrdzu- 0on the perimeter of a bicycle wheel of dizd0:ml9nd-reu ,e z i(ameter 70 cm when the 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 axis. Wsmd.vr y7/3 cghat is the centripe.y vrc3ms7d/gtal acceleration?

  How many revolutions per minute must a c;s0:t ud/o)octxa-1xz 9 wk fvircular, rotating space station of radius 1000 m rotate to produce an artificial :a zu d;)1o- fcxt9 kxtovs/w0gravity of $9.80 \; m/s^2$?

  A motorcycle has a ma+:kdjl n 3b nqd9y r,y.8kzxd;ss of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centrip8r nnly 3bd;dxjz+,k.yqk:9detal force on the motorcycle?

  A 0.50-kg mass is attached to the endg xt7x:/+imut vf0t/ 3 exlyb:m(ut c4 of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum spee e tyxl:c043/t +ibu(xxmt:uvt/fm g7d of the mass if the string is not to break?

  A stone, of mass m, is attached to a b ra6ya0ipx. 3ul zf p09-p/agstrong string and whirled in a vertical circle of radius r. At the exact to6ayp bl iz/gxfp9. ar0up a-03p 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 stone, of mass m, is attached to a strong string cs se)i/5lp 7og5 rd9s2mmik2 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 this ps s5psek)/mdig5r9oli 27cm2 oint is given by

  A jet plane flying 600 m/s experiences an accmtnz-rsmw z2 w/6v6 g,4ymd6t)l eok)eleration of 4g when pulling out of thktel mwm v)sn6t g/,rd2ow46y-)zz6 me dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertt9o lhvc)b- k7ical 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 with only one-hal co)l7ktb9 hv-f of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about sevenom *nw )klrr** times his weight. What is the minimum radius of curvature that a jet plane'w *)lr*mnok r*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 h wvag9:rf sv63w3)c fcorizontal curve with the tires on the verge of slipping. How fast can this car round a second curvewf:)6gvaf 39rccs3 vw 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. The my j8l w39c:zh-u(c5x r5on21ejvtfj centripetal force provided by friction u lvxy9fj :crje-3152 8nth(5zm o jwcis $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flatayjr+ 0,;cc6f,upsn) c 5olts curve of radius 50 m at a speed of 14 m/s. What must be the minimum coeffu+jf)ccca ls5,s;6 pyo ,r0nticient of friction between the tires and the road for the car to make the turn?

  A car is moving with rr 92)9u2r d,6ruzuezc +(nzmwe mu2b a constant speed v around a level curve. The coefficient of friction betwu)z6r9rer e dmm,2c9w2 ubuz(un+ r2zeen 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 bobsled w awa2k gm1 b/cn/.cnb04ind8 to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore fricgc nn4w2 wd8//ak .bim1bcn 0ation.)

  A horizontal curve on a bobsled run is banked at a by x)1di jl(o7.e0c z43wnpzr$45^{\circ}$ 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 ang8,dc9 jn gsxhe,l r-smh8 5h3ole of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 mrws9m, 6dguuug+j ,d jpu; 9,q 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 string is revolving uniformly in a horg-k7dwuq a:c pfj-+7oizontal circle of radius pfwd:cq7gko+a7 -u j-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 areaxiq . :fc2twl)0b7myx, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 5lq ybiwf x ctx20):.m700 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 consr5i6(0u6nvmv bb wyq 1ists 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 gravitational force on a 70-kg person standing on the z(fp+x n3, iebc)l8gaEarth, due to the g3x+ca,zi)f(8bnl p e 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 between two masses is F. If6asa a )vksiuf7 ig;zwks z(-.je76r, the masses are moved to half of thf s,s zi7 6aj)7 vk.;za(eruigas k-6weir initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from the t,og msv d1679rk/mglEarth will the gravitational fog, t6 lod1m7rv9sm/gkrces 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 ( m qpq-*xo;c uweqq)u3y -cxkc6.,jy$7.4 \times 10^{22} \; kg$ 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 tt(o1bf, lf. qche Earth equal to the radius of the Earqf(ftoc ., 1blth. What is her acceleration due to gravity?

  The radius of the Earth is R. Attm7cp j2nw/4 *m8hhgw what distance above the Earth's surface will the acceleration of gravj4hp2nm gw*tw8hc 7m /ity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dingi7dvw,kc( y 7g p15astance above its surface equal to 3 times the radi(gkngi ap,7vw1d7y5 cus of Mars. The acceleration 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, theukz/.r j5:7umya posxr om s7 mf8..*ex)mk a9 acceleration of gravity is o9xr)ra soux.ayzk:.s7 km .8/ j*pmmmeuf 57 $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N oimhxu,z),:an pabqaxx.78*i n the surface of the Earth. The Earth has radius r. If the object is raised to a height of 3r above the q8mn) pb a.ahzx:xiia,* ,7xuEarth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes ob/cq5d yf +k6knn3l4 from sea level to an altitude of 5000 m? (3fqn b+46n5o lyc /kdkThe mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite ofk nf2txj81vvb1-(f tx mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weigxt(fk 2jfv1vbn 8t-1xht?

  A spherically symmetric planet has four times the Earth's mass and twice:ezu29bg,x rz 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 o2buzxr9 , zg:ef this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, vlr9. xk++ s42 mchoxfwith th.k chvmo x2 x+94fslr+e Earth between the Moon 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 transportemkk dcqf)* idz91q*v *d 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 about thea;)op)s pyu e) Earth (i.e., it just skims the sa)ypusp e)); ourface 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 the Earth (i.e., it j fqulbi q.(*h2b, hk)h 2e:v5yyse1k sust skims the surface of the Earth). How long does it th2,i5yvs*2 q)ub:.le hqfhb(1kkyse ake 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 orbh z)8jb5j8x uyit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What isb 8u8z)jh5yxj 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 ;haey1lv(*j qk+ w00rn -kgq5 rk)dqb 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 c*w;j ehmrz t2of87h ndp* vqzfzm0/3 pq)k01with 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 or +ni)t-)h: nw8fniou12oha uvbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbitfiit)1nhao28 u+)nwo-: nuvh ?

  The planet Jupiter is :tr m(beoa9-i,x*i ty$7.78 \times 10^{11} \; m$ 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 S,kqwe 5l2 /q6t6iy9 ; aumsqtoun once. What is the average distance from Jupiter to the Sun? (The distance from the Eeq;ml96 5oiayt, 26qu qts/ wkarth to the Sun is $1.5 \times 10^{11} \; m$.)