Is it possible for an oeg,6r mm2zz 5-;,gik3 rghjjz bject moving with a constant speed to accelerate? Explaikhmz,je-2gim grjr,z65 z3g; n.

  Consider a particle moving with constant speed such that its ,mtxh3mo8 e hkpr+1/cacceleration of constant magnitude is always perppeho/83kcrm ht+m ,1x endicular to its velocity.

  An object moves in a circular path at a constant5 wx-, -*w+)ybjnnlja / tlpxk speed. Compare the direction of the object's velocity and accele),w+ bx*atll/ p-x-wjn nky5jration vectors.

  When an object experi w5/w smz-iwd6ences uniform circular motion, the direction of the accele/w iw-d5 z6swmration is

  Consider a particle movinxzc0 b iw,4 kv.skie2a-p.nj4g with constant speed such that its acceleration of constant magnitude is always perpe0k 2s4..exkni- z wji apvc,b4ndicular to its velocity.

  What type of acceleration does an object moving with constant i luu (tki:8yl 6q g igm)kid63f3:1gispeed in a circulagu3ld3 iif8um:it gik(g:6l k6iy )1qr path experience?

  What force is needed 1ox6y7 *j,m4l 9 xporsq5mmkk to make an object move in a circle?

  When an object experiences uniform circular motion, the direction of the net 8w7l o l-jdi+4 yict-aforce is +ld-o -ja w7ly4i8cit

  A roller coaster car is on a track that fm;ex17 *k/ hcj:e*jg ckif2vv orms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loopjvc/:mjk*he ec71g2fxv; * k i, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (1x,a:vjsou izec.9n e,ph 77 xmass = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the tev 7x xz:,i,ja coun7 p.9esh1rack at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical div 6lxhz9vmp0* ze then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force z xlv0zp*mh96on 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 curr1+tmnbsvgqv2x. u9 p1 (,ue xve of 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 constant speed a.o4bd x w.6ikjo/m9w 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 aroundd6/o 4x k.ma9wboij. w the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a+3u ei;6 0gz33t tonx8m(ga eu9uuety 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 curux3 u3 0t8 z+uiotea 3t( ;ye6u9ngemgve, compared to the first?

  A car of mass m goes around a banked curve of rad 4of.l n7fkr:agdrp45 ius r with speed v. If the road is friction.dnapf: 7lfrr45og4k less due to ice, the car can still negotiate the 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 bobslewe b6uwp+5yx j* (ve0ad run are banked at the same angle, but one has twice the radiu50b(e e6y j wxawp*u+vs of the other. The safe speed (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 Os 6sb 4q9c+ly p qsu:.3qpaxx9lympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," .ubq93 xqpx9sa+s ys:p4c lq6then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around ssy c z;y o;r:gywr0*sn47o2px v bs)aj1:vm. a circular path to have both centripetal and tangential accelerati 4svms xvyrrz1oj .:w;ys n;gpo:7 *yc2) a0sbon?

  The gravitational force between two objects is proportional ypit.xe; uvp(8ktz2m-uu/c r*m )2wl to

  The gravitational force betwis(5i) pv,dh ween two objects is inversely proportional to

  Two objects attract each other qgm 7--+mhv;jkn,)7qfw r cii gravitationally. If the distance between their centersmqcm g;fni)q r k+v7wi7hj-,- is cut in half, the gravitational force

  Two objects, with massez*pog-iy r8 ),s.huaecm*0d, t; itogs $m_{1}$ 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 mabv d+5r oexgc)v6 55j;r clo)csses $m_{1}$ 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 gravi 00 4skh lq;ckbk,w4cztation.

  Compared to its massf2gbe, os4ujac5q-81kmdj ;b5).xc b uuxa4q on the Earth, the mass of an object on the Moon is

  The acceleration of gravityh:t gp5z:5 -/ovhhd ehhr:s9 -oo4 ;kxwb xmx3 on the Moon is one-sixth what it is on Earth. An object of m gbekorx:x:9/t4w-;- oxh vhhz:3m55pshodhass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fr0fou 5/c e(oxydv -zs*yh69dilrre 43om the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon.uqvj9sq.fux 4 ;8lw m6uv7k4 l At what point is it beyond the pull of Earth's gravitf.7 ; 4qxmvvj6u9sku ll48quwy?

  Suppose a satellite were xu7u ly5q1mpk(2 s(;ufg ec1+*i nsa yorbiting the Earth just above the surface. What is its cenm+ ;5(* 1x2i pnsgfyekyus7(a1ql uuctripetal acceleration?

  A hypothetical planet has a mass of ha za+1ke z0ux78t6p p8dhwd*fblf that of the Earth and a radius of twice that of the Earth. What ie hzdzwb *70x6u8 pd+ptk1 8afs 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 itp)y/;u-tmyr0tuh pd ) is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass)upymyu -td/h)0rt ;p compared to the Earth's?

  Two planets have the same surface gravity, (vn) cwst) y6pbut planet B has twice the radius of planet A. If planet ) s6n)yw(vcpt A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the 0 .7e gdexmla0lux /d;mass of planet A. If planet A hadxa md/ul0g.70el; exs radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sph-bi,; xh wodzh +3dr1herical planet (mass M). Which expression gives this satellite's orbital velocity?+ oz- 3,x hdr1hh;iwdb

  Satellite A has twice the mgg9 3 px7c3lybl-2mcfass of satellite B, and rotates in the same orbit. Compare the two satl2lypfb-g93 m3 xgc7cellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compare)va,v kxejk w66vesyq8 f(l,+ the reading on the scale to the person's trq)elksj( 8 fea+ yvxw6v, k6,vue weight.

  Who was the first person to realize that the planets* tr.mfzu.3uzt )4mi5qtvay7ti/ (tz move in elliptical paths artz)r5iuymatq. z3t(4f / u*titz .7mvound the Sun?

  The speed of Halley's Comet, whirc 9zxkktfy3 r 2ac1m a9-:a0tle traveling in its elliptical orbit around the k 1t 3z0ax2mfr 9-c:arka9tcy Sun,

  Let the average orbital radius of a planet be R. Let the16*rqm*5/u oxp svesj orbital period be T. What quantity is constant for all 1m s*rs*e qx/u5 pov6jplanets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy6eqki *y31q1drag13 poe z y*k Andromeda, with the same orbital diameter as the Earth around o iygp3yro 6keq3q k*a1z1*e1dur 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 thrrk-386 zi r6 b),x6wqpmw3gv kh8yb7 ylg8w ue Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-thi wyrm q76,uw3lrk8ib-xg vgzpr )k 66y wh3b88rd of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.)w5k/ocujn 1 *b-(z+rgxiwhw

  List the four fundament q se+vmc-+v2tal forces in nature.

  An object moves with a constant speed of 30 m/s on igajg3x8pyu. +a9qy**t1 vcdg qo7v,a circular track of radius 150 m. c1*agyd3q+8g9uig,q.oj xytpva * v7 What is the acceleration of the object?

  The maximum speed around a level cup7qog f: 1s8awrve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all of:p so7wg18 qather factors remain unchanged.)

  What is the centripetal acceleratdhah :owp9+ lx bl;yzk(-5 ks*ion of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is movih-ld:kb(pw*ly zk5 s+x ;h o9ang 8.0 m/s?

  A point on a wheel rotating atz4gqp 99p6 x) k 81d *jxlas6 )ciq+ivoly8nmv 5.00 rev/s is located 0.200 m from the axis. What is the centripetal acceleyjs 4vq*c 6 vi pg zqd6nka9l8 xmx+li9o)18p)ration?

  How many revolutions,+ j3mm3 se-qwga )(kj3bz;qj,z y qng per minute must a circular, rotating space station of radius 1000 m rotate to produce an artific+3mjjsq3,) (gbznm e qjay -3k;q z,wgial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius tur858g zpxawtczb: ;xxw,vr4 o(* 1cu tsn at 96.5 km/h. What is ptaxsoc t*z(b,xu41rwzxwc; 5 g: 88vthe centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the enp(hj5b y aekg5(2j2 rrd of a 1.0-m string. The system is whirled in a horizontal circulap yebr 2(5(5rjakg hj2r 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 stro* 4qpz +nrkun3ng 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 this point+zn qpu4r3 kn* is given by

  A stone, of mass m, is attached to a strong soxd(9(zk)bl otring and whirled in a vertical circle of radius r. At(9k(zoxl dbo) 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 given by

  A jet plane flying 600 m/s experiences an a zg ve/d1:y7vyj;vg6 xcceleration of 4g when pulling out of the vyyjx6g dg z:;v7e/1vdive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (inopd-,az n:2 fh which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushiz:af -,o 2hnpdng 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 y z9 70-tiklumabout seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of i-t 7z0mkyul9 a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizo:sg.ezkq .pf* p.6unkntal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assufp gzk* 6sn q..k.e:upme the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiatingc)pwzdiaay 5 p0+s c21 a flat curve of radius 50 m with a speed of 20 m/s. The centripetal force c isyca1) p02daw+5zpprovided 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,kf+zx 2:vqz )rqf3wn a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the+)v2kq ,fz xqz: 3frwn car to make the turn?

  A car is moving with a r4f mb,w8n+i1 fjcryfww)s2 2constant speed v around a level curve. The coefficient of ,ffywbr2f)1+ nwj2 m ri84wsc 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 the road?

  What minimum banking angle is required for an Olympic bobsz 0.cnr)1s zyf8cbv3aled to negotiate a 100-m radius turn at 35 m/s without skirns z381.zcf0 )yc bavdding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankew 7u0rtl fm.;*e.i ki+0cm5qj9e. wbe:tokuqd 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 radius 100 m, banked at an a11q6skelv my (y*yv*w ngle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked a7lnxje :j3by7+-y1oz evban. t $45^{\circ}$. 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 uniforml ap (o ucz)rkv* 1 o0d/jl7/tlqhzh;7gy in a horizontal circlecl/ qda/0 o7)vzl1 jt o h7z;k*gpuhr( of 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 atpvz-5 2lb )urvc+jdi5 a uniform rate to a speed of r ub +vlj25z5 pcdv-)i45 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 consishjj yuz)3qb*7 5u;al nts 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 omzs*t8q s)i*0;rsd cz l2f7aln the Earth, due to the Moonfl**q8cdm)sl2 ;tzsis 0r7z a ? 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* (1fz(ppv + hrfnx6we masses is F. If the masses are moved to half of their initial distance, what isfxp(ehrv +nf(w*z 61p the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what diskfqsa5fn/h9, tvz v6g .7t3tsa5u pg/5lkjw-tance from the Earth will the gravitational forces due to the Sun and tfz9k s js6l/wuvnght. ,-k3tf/tpa5gq 5a5 7vhe 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 i 4n zrbo6k5 fbkl+e19ds $7.4 \times 10^{22} \; kg$ 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 ou 1.bx f/i9 zbi lssmknn6x y4u8t2l3v1t for a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration duz b1b1nll xs mxfi24t.9iyv3 s6/ 8ukne to gravity?

  The radius of the Earth is R. At what distance above the Earth's 8l 5hflqbipzd8z/p7 5 surface will the acceleration of gravi5 plp5lhbzq/8 f z8di7ty be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dist4y l3 mnwzcyz4 16e +avjq5f6pance above its surface equal to 3 times the radius of Mars.nze3zmy1 6qw lpyjf4c a64+5v 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, the acceleration of q3ec(vy 7:bsdgravityye:cvq s3d(7b 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 the Earth. The Earth has radijyopyj4iys5:4 rjv ;(ne78 bius r. If the object is raised to a height of 3r above the Earth's jory4j8e :b;p7ivsy( i5n4jy surface, what is its weight?

  By how many newtons doekx1e02aa(.edm w f bc-s the weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radi- ak.0e(xedwfmab2 1cus 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 ab ymd *(lmxw1x5ove the Earth's surface. What is the satellite's weight* mydlx mw(15x?

  A spherically symmetric planet has four times tepyr2y)q,zw ohg7 2p1he Earth's mass and twice its radius. If a jar of ppe,oq2y h21)ypwg rz7eanut 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, Earth, and Sun all lie kki wj7pq)y, u7 v+es6n1 vp0kon the same line, with the Earth between the Moon and the Sun. The Moon has p us ekvk 7,0j1pi n6)7ykv+qwa 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 f5x p*1rz)w xhis transported 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 ojxx n hut25)8lvr: ;*cck9mfqrbit about the Earth (i.e., it just skims the surface of tx :q *cr 2c8vft9m);kl5nhxujhe 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 jus hrxl0)1;xrmet skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radiu)l mhx;01rxer s of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of thez2/upqpj ,ssld0s, bqq)mj)/ Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of t j dmbs) j)s/q0s q,,pl2zqpu/he Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of s(qacta87 7zc:tg:l p $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with z3:jgfjt u5;u g x,sx+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 hbra-wpq*+/h ,npck- mba6g2 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-nhpqw g/cb- pk2hr+6,b*m aa an orbit?

  The planet Jupiter ishq5:i 8ni25ido lh b9ebnbn(; $7.78 \times 10^{11} \; m$ 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 Jupzj;hmjhro* 0(2 bt3)g4wr/u phb l8 ytiter 12 years to orbit the Sun once. What is the average distamhwbu 3r hy4t8(ot*j; rjz/pb0g2 lh )nce from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)