Is it possible for an object moving5sh/wm4*xti c with a constant speed to accelerate? Explainm4 it/sx*w 5hc.

  Consider a particle moving with constant speed such that its acceqm n a:1f- qnb4--s8byz rw*ippp 6;xeleration of constant magnitude is always perpendicular to its velocitypne-8 fw-;m:*6b-i pqq1 pnzr 4asybx.

  An object moves in a circular path at a ce4)i9pyt 1no )lggr/sonstant speed. Compare the direction of the obje )tgoyi /lpnr)9sge 41ct's velocity and acceleration vectors.

  When an object experiences uniform circular motionh*rlj t*e gt,;, the direction of the acceleration ishlteg r*t; ,j*

  Consider a particle moving with constant speed such that its acceler3,qk3e (w/m obm rdofyjv +1l3ation of constant magnit 1q/,(eomy3 md3+ jklbfr vow3ude is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant2 5xlk. yl ehic9f1nx5 speed in a circular path expx5 ch k.n l51y9e2xiflerience?

  What force is needed to mak kyvb8,)jfxnl ) t9nkt50o5yje an object move in a circle?

  When an object experiences uniform 2+n7 zig(jz6trwg(- f d6v dylcircular motion, the direction of the net force is6+tggv lf wy- i2rd7 jzz((nd6

  A roller coaster car is on a track that forms a circular loop in the verm4rer9jfy/n772u rtxr ed e,7 tical plane. If the car7rn4tj 7r f/2,rd 7yeme9eu xr 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 omb50b8ptpkai0 j; ,taa9 6vmln a track that forms a circular loop (radius = r) in the vertical plane. If the catk5 pap0,atbljimm;0 a68v9br 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 semi-circu2: ;ssnf/ipo*/ tfa bzlar arc until it is going straight up. Just as the plane is at its lowest point, the force *b;f2oiz tss :/nf/paon 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 omm; fw. +o3aol)znppcv8 -zvhl a/ ,c/f 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 c36is0z2g / ug hnizebjjm3l,0 onstant 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 foz /3el0,jz6gsj3mbhu 0gn2i ir the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then 3(jl/fxzif0 gtknfd+o 2g9a-it goes around a curve of radius 2r at speed 2v. What is the ce23of -dg(kj ftzfna90gi+xl/ntripetal 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 ra z bll) 6*:k0ndw,jblhpj. xe)dius 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 nox: 0jdhl )llj , b6wnk*pe.zb)rmal 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, but onpojr)tnb) 3xdg-2z 3deb4gu5 e has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the s3 epg)n) 4td bzoxdju3-r2b5 gafe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not con ue ,xt:a(1kbqstant, but increases upward u1q x(:tk,ae bfrom 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 hvimj4 rx-oo1u.5a tvgvg4t*;oi 25 karound a circular path to have both centripetal and tan;ku5-*tri1oa vj2h o4gt5 xmig.vov4 gential acceleration?

  The gravitational force between two objects is wl j7vy jcnwwrt81x+e0*r0 .u proportional to

  The gravitational force between two objects is inzgt32 ogdm.2ax9 qa,;ul2 ssmversely proportional to

  Two objects attract each other gravitationally. If the distance between thqnptw kz 8*lf2z5pwat-;,: d qhy:h i*eir centers is cut in half, the gravitational forctq:;dapnhzkfzq*:p8* i5w2l , h-tw ye

  Two objects, with mass3t3 5d5v ufwhbes $m_{1}$ 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 ;d .rec7zpx0wu g2zu/$m_{1}$ 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 graxvw41 2vct*8eea nn6y vitation.

  Compared to its mass on the Earth, the mass of an,4f mwc k4:v +8zxd,oo l:lasa object on the Moon is

  The acceleration of gravity on the Moon is one-sixth cbq/0 jo8/+ 6udmdx cjwhat it is on Earth. An object of o0dc uc8 q6j+ //mdbxjmass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket'sb )v8 c *rw/vrl p1e5k1ot63ep phs2bzv ,i*oa weight

  A spaceship is traveling to the Moon. At what poinvtf:65 rchbb7j/(lep t is it beyond the pull of Earth's gravb6(5:pe7hltcb j f/rvity?

  Suppose a satellite were orbiting the Earth just above the surface. What is i3zs9jcq.g:d w m6 sajjvs ak,)8j*l v*ts centripetal accelerati 8:cd6agzsa* jvj , ljsw*q9v.s3 )mkjon?

  A hypothetical planet/kaxz e8yp :rn;fxz ;i9dv1-a 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 gravity at ta; /9f z8pe1:- x dax;irknzyvhe Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. ul- kmg7 xzp:uz(,kkq9t)p ;f The radius gk pzuk ,k);(f9xm:7uqzp-ltof 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 zh;(f jgkuadu6k .m+ 4u2kv5p surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planet B(4.a hm6vg k k5;ukjuufd 2+zp?

  Two planets have the same surface gravity, but planet B has twice t7ap lwtlrs 9 +*l99b8l rwy(vhhe mass of planet A. If planet A has rb l9h9+asp9wl t7y(rwlvlr*8adius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius ppy0bb/t;h/(,f.4 ubty a g mlr) about a spherical planet (mass M). Which expression gives t ubb/pp ;ya,40.y /bmhf l(tgthis satellite's orbital velocity?

  Satellite A has twice the mass of satellit4qgg/v xr7+w6/a vvd4s;1m 6-do cbu)nqitkwe B, and rotates in the same orbit. Compare the two satellite's s6u4 axmwri;o1 +7 tw4sdvgc- / v/qndqv kb6g)peeds.

  A person is standing on a scale in an elevator accelerating downward. Compare p8 t1klgy, l2zthe reading on the scale to the person's true weight. k2z1p, tyl8lg

  Who was the first person to realize that the planets move in 0l cp/7vph5r nelliptical paths around the Supn7 /lv0 cprh5n?

  The speed of Halley's Comet, wwnt wyn2hani t8 oh0+95 a-;kchile traveling in its elliptical orbit around the Suna05h89-yw ;ahco+nttn2ikw n,

  Let the average orbital radius of a plane9k r8puci.)m qt be R. Let the orbital period be T. What quk.cu8imp qr9)antity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit arouk / ,avdi( h0l,unihnt78xt9f nd 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, what will t7i ikldn tx9(tnf 0 a8/,hhvu,he 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 one "astronomnob2vi55q :f3 5izyktfwcc2 1ical unit" (AU). bf nt:c52co2v53zkif5qw yi1 An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.tx smsi dx9ldgh/1 qi )3w,4(x

  List the four fundamental forces in8vfi e hqyz ) tp0mf,wc7-5im; nature.

  An object moves with a constant speed of 30 )k4r xq/uwk+hq5m ky( m/s on a circular track of radius 150 m. What is the acceleration of the objectkmq(kwq+ /kr) hx 5u4y?

  The maximum speed around a level curvyb)g3r fp1o/ 5vbx rd5e is 30.0 km/h. What is the maximum speed around a curve with twice the radius? rv)fd1 xy/g r o5pb53b (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a poi(umo78 d+ v vqnob)s-d 4r*qh;yeur6vnt on the perimeter of a bicycle wheel of diameter 70 cm;-sddub4 78(+ rveho* oqmrv)nqy6vu 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. W;vo2a: z7kw8( 5ztv0itgk yxvhat is the centrip; kiv2x7w z 0zt:vvt8gy k(5aoetal acceleration?

  How many revolutions pe4 e+f-wceqy*wr minute must a circular, rotating space station of radiuw-y 4ceqe f*+ws 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mase mv5;ei .gp03i lj4(qrazyf6s of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. ie5q (. 6r0;fj4leyapg z3vim What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of.;e fcm8, mhzc 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; 8c, .zhefcmm maximum speed of the mass if the string is not to break?

  A stone, of mass m, is agsv+7k4 df2c-uxj f.httached 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 h d sxf24k-+7ugvfc.j this point is given by

  A stone, of mass m, is attached to a strong string and whip3xm/ pwx3eb* rled in a vertical circle of radius r. At the exact bottom of the path the txepbp 3/3 mxw*ension 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 experiences an ac -9 gfqpgh6y0)9uxn 7 ov jdwumtz/c(:celeration of 4g when pulling out of the dive. What is the radius of curvup06z-um(ht7g cx dj o v/y99gwn)qf :ature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is bene4p0jz+fe-3 fnhu o r*: w.pitcath 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 weight. Htwj+3 c.fefphpr :0unz4*i-o ow fast is he going?

  The maximum force a pilot can stand is about seven times his wenp bboax7sz32b m1e is159v;kight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of am;1z 319axp2nbi sbkb75se vo vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an / +qike0a(x a-gyk u+f80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car rounfi0(+uka+gqxk-/ eyad 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 wi7txcbf ln*:2 6i+3vok dxzu gr5( v)qxth a speed of 20 m/s. The centnbk(z lxq76dx) tv3v:5+cx*2orug i fripetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a fld,ofcc6 w4s hd9:t2y1 j lx.oxat curve 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 the tujlf6d x tcc x2dhs4:w oo91y.,rn?

  A car is moving with a constant speed v around a level curve. T wer(:1le h7yxhe coefficient of friction between the tires and the road is 0.40. What is the minimum radius of 1le (h7re :wyxthe curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 1008;-b aoq/ppvvr qlg/,r q :g.x-m radius turn at 35 m/s without skidding? (Ignor ovg,.b /:lvp-x/rg ;8pqqqare friction.)

  A horizontal curve on a bobsled run is 5s(69 0ke ;1havamu uc10v;f-fs uutbmlwk6zbanked 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 s8fvij.p7 v 65fugi7uradius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 800qhvu fq,d; h7ak6py0 m 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 en9z+bn wc 2fce:d of a string is revolving uniformly in a horizontal circle ew +2nzc :9bcfof 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 cne*ce 4mg* ;v 8a1yizt i,pf2far accelerates at a uniform rate to a speed of 45 m/s in 15 sii48*f2vf* 1nzyeace; t gpm,, 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 .pe3 pgj6rt2gof 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-kx3g qcsunx.t:vj2y5 tam8, h1g person standing on the Earth, due to the Moon? The mass of the Moon is x tvhxcjm.uqa :8 s t51ny23,g$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses 7b ;y mao;w/bais F. If the masses are moved to half of their initial distance, whaywm/aoa;bb;7 t is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from oh08 swk.rwf r+a mp2;ql4f6)d1cs5 gurorn5 the Earth will 5 5+nss)o f6.w 8r4k1dr gfh2mrplc ;qa0orwu 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 xzf(ru phq1u 06f7 za(is $7.4 \times 10^{22} \; kg$ 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 abovv ,suxc/cc4i.p.qso pcjn, /7k.e /ls+ur)mie the Earth equal to the radius of the Earth. What is/,/ i7vc),ulie+.sscqokmx ..n c ps p/4 jucr her acceleration due to gravity?

  The radius of the Earth is R. At what distance r :kljdmp:*r+syg 5u9l) u6x wabove the Earth's surface will the acce*uy wslm5u :jxrlg :) p9+rk6dleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abovs9py6yx cpz+s 2.3dqq8 qlpr6e its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the accelerati8xr6l y sq+q.326ppdzs9cpqy on of gravity on the surface of Mars, is

  At a distance of 14000 km from s 0lqcsny -g9g4+j 2qlfome planet's center, the acceleration of gravity isngslj+ 0 l-cq94y2g fq $32 \; m/s^2$. 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-3dwx9;q z yav Earth. The Earth has radius r. If the93; dz- aqvyxw object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg peveag: ;xs/j, srson change when he goes from sea level to an altsv; /ges :ax,jitude 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 the;b; o/yp8kbvcs*0 sdk Earth's surface. What is thsbcobp /k v0yd;;s8 k*e satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its y .j2v(gkeu4tcyi 9xfh3:+euradius. 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 planet? ix(he vjf. u932:cyteuykg+4

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same n4 r;pkly+b 8fline, with the Earth between the Moon and the Sun. y4+fnlr k8;bp 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 ek: r9f49g 9oyne2zy bthe 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 Eartha4zfmdfr- 8j6x 3pbf5 (i.e., it just skims the surface of the Earth). What is the speed ofb8m45f6x- f pfd3jrza the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low ciw 3 p+x,mq.cprk 1/g/fljhnajzv0pi, k 9(,ic rcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? z1c3jgc n+0 p,il akm,rpi fh/,9k./qpw(jxv(The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circuycn ,hv2,fng:a)xky,gp g-,tlar orbit 230 km above the surface of the Earth. It is obt n2,,ka:,yvfn p gxg),hg-cyserved 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 Jupiterzidoj3itpc ysd- 7 .kp ru 20j-*6+auw, has 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 Ju9 ez:xhl z4x;gywyz;-* (bh5 q(ztimppiter 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 z1ryfpge* l;2circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 *1pg ;ey flz2rdays to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ismp0os p1s c xz)zw8(r+ $7.78 \times 10^{11} \; m$ 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 once. What isce/lsbro*9dy-c0 +e p the average distance from Jupiter to the Sun? (The distance from thb s yrp*le+/o9 dc0e-ce Earth to the Sun is $1.5 \times 10^{11} \; m$.)