Is it possible for an object mo 9vim4i1(uy tjving with a constant speed to accelerate? Explaim i9vit14j(yu n.

  Consider a particle moving with consta)j-f.b: rfu9sl/uvhnnt speed such that its acceleration of constant magnitude is always perpendics ubf:-hlu9./ nfv )jrular to its velocity.

  An object moves in a circular path at a constant shs bsm+bsi(:wt )qy7(peed. Compare the direction of the object's velocity a bqs:(b tshm+7)iyw s(nd acceleration vectors.

  When an object experiences uniform circular motion, thc zpc lr815+ f7xwnu.fv5x+umy:h0 tbe direction of the acceleration isclup05fmx fwhv:zynu+51c +rx.8 b7t

  Consider a particle 3 b 1gh oud+,:j3yyqagmoving with constant speed such that its acceleration of constant magnitude is alghyq1+dg:3 by,uo a 3jways perpendicular to its velocity.

  What type of acceleration does an o mn)y)qxu7+vk h ,:;wc)na2oamn)c uzbject moving with constant speed in a circular path expx2ovmn )qck:ayc),uan;7h)z)nu+w merience?

  What force is needed to make an object move in annt2 dq(r bp l8/ip/,i circle?

  When an object experiences j.yh8m*z7e ,fzc qxwz 5fh7n qwcr6,6 uniform circular motion, the direction of the net force h,f n5x7w .qzjf*q7rw ezcy68z6m,ch is

  A roller coaster car is on a track that fm s,r:6sqn/jx wh sy,:orms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top n6sss m:x ,h, y/qwjr:of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is fz5s k q0f30vjon a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the f0k0jsq 3v 5zfloop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then followc + jd vq jkknx*s36a)/4szd.ns a semi-circular arc until it is goin*s x 6j q3 /dc)k4ksndvzna.j+g 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 o:;a,hyaz. mivf radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a cuak0gk .)mmuqx7g tc+5rve of radius r at a constant 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 for the second time, compared to the first 7+ctguq.5mkmak)x g 0time?

  A car goes around a curve of radius r at a constant speed v. Then it goes aro2/ ully g/dp-vhwdj6r32le( g fn 1a9hund a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compjgulf6 y9 elhvda3w( /1hd2/p lgrn 2-ared to the first?

  A car of mass m goes around a banked curve of radius r with speed v.t;es*tggv alfcu81 1h77vmq n: xz/ ,d If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on tc7lnmqe1 u vsa *zgtxhdg71/vf8, :;the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but le3lydu)8c+pv -f kr z05,sfrone 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. Whavz l rl3fkr,y)es0fcp+- du 85t is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympi kdko-.h) dd*k3 yr(cxc bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wal dr*hdk.kydo-3)(kc x l," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circultx h:k4fa y.txn(2p4b2(e xoyar path to have both centripetal and tangential acceleraf(xx2t4bo k4yep t a.h2:x( yntion?

  The gravitational force between two objects iylrvg 4y*r(at;6rd ak n*y0;:u 5qhxus proportional to

  The gravitational force between two objects is inversely proportiox0zfm 3o;l (rxnal to

  Two objects attract each other gravitea,,tdb )3( onkg2ce yationally. If the distance between their centers is cut in half, the gravitatio, 3 ngo) tceyk2(b,aednal force

  Two objects, with masskhqmnind y klk ;bi1988h1i5,v:.tz bes $m_{1}$ 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 massesuwc +ju*4zj,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 universal go 0s6h;;muxmo3j i kz:ravitation.

  Compared to its mass on the Earth, the mass of an objezejr (jdsw, d:cm3/d*ct on the Moon is

  The acceleration of gravity on the Moon is ongmg-.n w; 0klh1/5b5k7g juav)z ppkke-sixth what it is on Earth. An object of m5pg;u7 p5hkn g m. k)vbga0/klw1kj-zass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weih6eyn+v 2ffh 1ght

  A spaceship is traveling to the Moon. At what point is it beyond the pull ofo) wl lz393sgt Earthol t3sl9z w)g3's gravity?

  Suppose a satellite were orbiting 2)g en;n lw7ookxqh:+the Earth just above the surface. What is its centripetal accelerat+ ):enwog2kq;nxhl o7ion?

  A hypothetical planet has a mass of half that of the(pl14.igre9lt.be ku1x c+ zb Earth and a radius of twice tha+gc irk l1t bplzue 1x4.9.be(t 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-sixth what it is )ie )pwogk;:t4r( g9wkb kko/on Earth. The radius ;9tk:ok w) k(r4i)k/g gobwepof 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 gravity, but planet B has uv abls *8w5mtg/dz ;8twice the radius of planet A. If planet A has mass m, what is the mass of p8vda*g zm8l t/5sub;w lanet B?

  Two planets have the same surface gravity, but planet B has twj a) k4+rmyey h0p9+avnbpfe/qg:5 zp ::+w egice the mass of planet A. If planet A has radius r, what is fj4h ::p+b eaak0yp5g mge+)z9/+nyve qrw:pthe radius of planet B?

  Consider a small satellite moving in a circular orbit :tce rhf:q;kgibfg f2l5-/e/ wg8p 2m(radius r) about a spherical planet (mass M). Whichi5g8r -:c eewbqmg;gf2f:/2kt/fhp l expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellitwbqn3 ha6ad9b*h3t jhu . sv0-xctg80e B, and rotates in the same orbit. Compare the two sagu*x0 ta6qv ad .3hj c09hs83-bhn tbwtellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. s8*;y v 0oy)oihmvyn.-w wdf 6 Compare the reading on the scale to t6n)wf8 ho d*v.- wo y0ymsiyv;he person's true weight.

  Who was the first person to realize that the planets move in elliptical paths ar5 sgsa2 07ipofl2 4brfw+q5jhound thw sfq0l7f 2 op5riha+425bsjge Sun?

  The speed of Halley's Comet, wh hmj+mmn )7;gqpwg;c1ile traveling in its elliptical orbit around the Sunpn );cqwmg7;+gm1mh j,

  Let the average orbi3zyymrv3v8y8(+f 5 w 40vdlg gpin 9imtal radius of a planet be R. Let the orbital period be T. What quantity is constant for all planets orbiting the(my89nygz3v5ml8 3 g0vp4vidiw+r fy Sun?

  A planet is discovered to orbit aroul;h6 /s 8dyofiawkj2*nd a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that sjsl d6i a/ ;28hyk*woftar 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 ti5:j naciz9 f)-o :tvxhe Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-thiri5f-:9j:xtvnoa)ci z d of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.3 tkwd:z( (d d/gi:isu

  List the four fundamental forces in navcfvgmjdh3+. d8ld3 e8 m;:jnture.

  An object moves with a c2jubm9wu1ap6duox9i-* 6a-ag gx c)w onstant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration1wu6dpoc )*ju i69u9b-a-amx2 gxagw of the object?

  The maximum speed around a level curve is5f4/* n tsjuqlgr:s/t 30.0 km/h. What is the maximum speed around a curve with twice the radius? (A:g*tnqf 5srslt/ju4/ssume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycl 7bvlilyvi4:e z7c 1/m5m6ybje wheel of diameter 70 cm when the bike i7vibl6zbmec yv y mj 574i/1l:s moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m fam8*hug6 :hvh sd/,nnrom the axis. What is the centripetal acceun sd,gh*hm 8:n vha/6leration?

  How many revolutions per minute must a circular, rotating space stati4xmp-sm c. h;bon of radius 1000 m rotate to produce an artifx;-hc m pbs4m.icial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It gomtvppo-r 2d5 n(-gar8es around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force p(pdmgr-2otn r-85 va on the motorcycle?

  A 0.50-kg mass is attached to1wqfp1- efi+q the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the i+wffe qqp1-1maximum 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 a-a5bb0u+ ulo2yy5 1iez az/6mg cwsu( ttached to a strong string and whirled in a vertical circle of radius r. At the exact top ofb2ea/wumc56u-z lgb 1+yzia ( s0yuo5 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 sbt lv.8 zsc226i dh0rxtring and whirled in a vertical circle of radius r. At thez ts.lv bc0di xr2h862 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 given by

  A jet plane flying 600 m/s experiences an a +abf)*yzdk x7cceleration of 4g when pulling out of the dive. What is the radius of curvature ofkdx)ay z*+ b7f the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center ofykej l prt,bgi,37* b-em3x*f the loop is beneath him) of radius 3200 m. At the top of his pmte b3- y 3ek7gf bi*r,jx,*lloop he 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 w;yo(ptw0ux1c b-(ppz i))k sweight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerat1ps)(-u;t cpp xwzb)iyow(k 0e at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tires hz; b4xzi,hgv y27n7:gaj ll4on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume ta4g v2l,j;yi 7h l4z znh7xgb:he same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flao7fltca7:ti0r y1z( haq4 ;z at curve of radius 50 m with a speed of 20 m/s. The centripe 4izatac1: f7;yh70loz (trqatal force 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 at a speed of 14 m/s. Whap:d/dn0e 60 kqwycn7 pt must be the minimum c0wn0q/ eypndp 7 kc:6doefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coefficien vgg0(d pqp4ebcoi calc )0.5e564 wagt of friction between the tires and the road ip e gg 0eiq4vgaaw5c 05(c.cdpbl4o) 6s 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 to negotiate a .dh 2dbr xzfnj3o/6 gmo2-t)i100-m radius turn at 35 m/s without skidding? (Ignore frictio 3bxjhm2 f-ngdo/r z)6id2. ton.)

  A horizontal curve on a zp.x/v ;xj;py ,at/o k3vy6myx-c dr1 bobsled run is 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 curveqkzmj74f3 526 bkb wjh of radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked +8ev:o85nf,g zpwfor3cw4meat $45^{\circ}$. 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 revntlilw1iky o,;z.yl s; r4.m2olving uniformly in a horizontal circle of radizl sk .;llm;ory4 y2ti1,nw.ius 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 uniform rate to t-h*;crpm tom :oz5w) a speed of 45 m/s in 15 s, moving on a circular track o mocm :tp worzt;5*h)-f 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 ;;ylukg 8y8gqc:lkyh4a p0r+ 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 onl5emv zl: /-o jm8e*: jwm-uun the Earth, due to the Molnm8e u:/:e5vjuw--ojz*l m m on? 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 masses aa azmre792g4z 6h 6z5tr-esm s.z)apure moved to half of their initial distance, what is the gravitational attrt gzaz e45mze) r6za.-hus m6rp2sa97 active force?

  For a spacecraft going from the Earth toward the Sun, rq4 cnx rgd630a(yoci(+ n-myat what distance from the Earth will the gravitatiomr6igcq 0n (dc y(+ao-xny4r3nal 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 zv*bwqnl9 l ;9$7.4 \times 10^{22} \; kg$ 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 Earth equal to1vax0vc+,rfg n uq 9h*vc9opj i (:u(y the radius of the Earth. What ( c* vv 9i0hcr:jx,pugvao9u (y+f1qn is her acceleration due to gravity?

  The radius of the Earth is R. At what distance abov5 a+w dn/hyjh/ovjc9,s):yt6mmb9u o e the Earth's surface will the acceleration of gravit:jc/nh/u59d, 9a t jv owymob6)ym+s hy be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dic+wy6 i,h1shim6n :lomx -pew e/)s e9ky92npstance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as comparedl pwc-,6m skihy 9iwe2:)x sp9 1y+mehenn/6o to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the accelerati. 1v,zcoxq ;rdon of gravity is dq c1xo ,z;r.v$32 \; m/s^2$. 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. The2t9vvbqi3 z8m(* kxpc Earth has radius r. If tt qmcz 3kp289*vbxv (ihe object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight ogswfq(q1b pd -;lwu 01f a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius odsqwqlwf1;ug bp0-1( f the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is a 237xh .(pel1 zth .n5jmsjbbot a point 3r above the Earth's s.h2zbph7m3oljx ts (e 5b1.jn urface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice ird ed8 cs925,atz5essuj-j1cts radius. If a jar of peanut butter weighs 12 N ondjs-,c 1e 5j2ats9 85ceuzsdr 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 h*7uzot7gr;5o m 0z2y4w nq hdon the same line, with the Earth between t75 qz7rt;u hy do4mw*hn0z2 gohe 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 trz tt0wu5z73r l bvm1)vansported 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 aboup3d4di a4+;z2;eloxefy ts(mt the Earth (i.e., it just skims the surface of the Earth). What is the speed o eypl( +z;axe4sfdtd;o4m3 i2f 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 th y8b2kl(xg-sm,j3 s oae surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earm8 o( ba g-sl3,xy2jskth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. I-:riy4: drm gyt is observed to have a peryr4:r -dy :igmiod 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 diame 6ri4+ir lk+-lcn4b2 ofpvfi:ter 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 jr) xv)z.yyc 6with 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 radius rx:s3 j3i sijz32wb c*r, and moon B has orbital radius 4r. Moon A takes 20 days w3xj3i:3* r j b2zsscito complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is hc/4rvs cux./bt-)c h $7.78 \times 10^{11} \; m$ 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 is the averaprghg9(o y3jeg4 ceuv(:x;7 yge distance from Jupiter to the Sun? (The distance from the Earth to g3gov 7cgxejp(u 9e:yh;( 4rythe Sun is $1.5 \times 10^{11} \; m$.)