Is it possible for an object moving with a constant speed to accelerate? 4- uqu,idr, -y,qlkt xExplain.l ut ,udyiqr4-- kq,,x

  Consider a particle moving wiid+y .79ccab7j0 qf jnth constant speed such that its acceleration of constant magnitude is a 7db+ yi.ajf0 cn79cjqlways perpendicular to its velocity.

  An object moves in a circular path at a constant spee/.t;: t7vm e0 at 4zwb7ya4podmdcsg,d. Compare the direction of the object' /emz .s7 g pdv att44,tmbwc;0oda7y:s velocity and acceleration vectors.

  When an object experiences uniform circular motion,smmuc7p 6*.7 -(emf )x5hxzsjsker f5 the direction of the acceleration i-(5 p 5m7 mmjsfe)6zferssc *ukx h7.xs

  Consider a particle moving with conhjne46 ymln: ip3ph;4 v tjb:.stant speed such that its acceleration of constant magnitude is always perpendicular:.h3p:ibtn y vm j4nl6j4eh;p to its velocity.

  What type of acceleration does an object moving with constant speh wqb3,br(9qa ce,w/o; ,p chfed in a circular path experienoeap9h/ h,r;b3wqwc, qb,fc (ce?

  What force is needed toncw m, - 5d4,dsq/mkyb make an object move in a circle?

  When an object experiences uniform circular motion, the direction of the i +yitbly xwj8/:,:pgfw+/ snv;+ ov bnet forcei:wnl/:+jws v/yv xyb,bf o+p8 +;tgi is

  A roller coaster car is on a track that for g2pwlqe o042kms a circular loop in the vertical plane. If the car is to just ma2 q04pw elkgo2intain 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) i 8wb1/-ytyesixx4m a /s on 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 loop, what is the minimum value for its speed at that poinm e1 xx4s-b8ty i/y/awt?

  A pilot executes a vertical dive then follows a semi-circular arc untiu cfwif9 lg( *,; k.35 ya7emtz9rnc ix/nu0eul it is going straight up. Just as the plane is at its lowest point,ua9rz/x gf c;ltui5.im (0fe,yw uek9n*3c n7 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/ut/0d+x7w-ytwg be i 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 v. Then it goes arou7jf tr(zl.n2 qe-km*1ex rdk, nd 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(.r-*l jqxk ,e trf1nz2kd7em time?

  A car goes around a curve of radius r at a constant speed v. Then lsll9o0r 33n7 dv,rju 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,dlunrv3sl ,97ro j 03l compared to the first?

  A car of mass m goes around a banked curve of radius r qa z;h*r t2hbx6gu9c. with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal forcebz.9q*r2c6g uha x;h t on the car from the road is equal in magnitude to

  Two horizontal curves on s+y)+ r d+c(t) jwxfriuvb8-ga bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (+i) 8d (+t gcr)y swjbfv+rux-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 trps,3 - 4 ebffo1j:/vh cnmy4xhe Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, th ,r s44v:cop-meynffb1 3xh/ je 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 7 .mj)7l6u hyzeqjc x;moving around a circular path to have both centripetal and tangenti ; yhmz7.qeclu)x6 7jjal acceleration?

  The gravitational force between two objects is proportionagq/:e dtyeg9z3vkxwc(o0 *(8g y /ib5akwej7l to

  The gravitational force between two objects is inversely pgkh mpd2 r*kjmm.y, 42roportional to

  Two objects attract each other gravitation3qv ,)t gu9vnvally. If the distance between their centers,93ugvq)vvt n is cut in half, the gravitational force

  Two objects, with massesl8bys (*i 0* d/;lgfp kkre-pd $m_{1}$ 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 .a d6 inm h b-ptlw,5x:1zg,kp$m_{1}$ 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 gravitatii51 otksa7- aw r69dlvfwz)0 jon.

  Compared to its mass on the Earth, the mass of an object on the Mohb z5k7g28omkon is

  The acceleration of gravity on the Moon is one-six.k7se)rthl 2 s i6dcn1 0 vnt2r.9fvoeth what it is on Earth. An object of m)76ve9c 1 drnskt0.oef2 2hn rl ivst.ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Eo5mmx4 p1h+l uarth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what poijlbe o7+/ 8aymf2zfjc;) g d7mnt is it beyond the pull of Earth's gravityffm+/a7ycj)ol dz2b ;ge8j7m?

  Suppose a satellite were orbiting the Earkfbpc*,:5gi(gcaf vkv p) yt0(na 3z. th just above the surface. What is its centripegf(:.0(kgcv* t3 ikz a5v, pny fap)bctal acceleration?

  A hypothetical planet has a mass of h/nb u +h2oiz:nalf 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 h2z/iub +:n ong, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-siaay+ souzum,(h4oots :h7w30xth what it is on Earth. The radius of the Moon is one-fourth t0ohowau3,muao:z4 + (s h7sythat of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same suc2 h l5y8em/garface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mas 5/8em2glchay s of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass o9xx:9z 5o7 lbwm2;hnl/d-y -jf(7kynoeq ry ef planet A. If planet A has radius r, what is yfkr9y olh dxo (7jnme- 5 qb /n9xew2-lz7:;ythe radius of planet B?

  Consider a small satellite moving in a cvqn 3af 9ckp:qc6u:.lircular orbit (radius r) about a spherical pla:qfcpkv3 uq9la6 .c :nnet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in thel7 p*1 wxcvor00wcrz2 same orbit. Compare the two sat7z vc 0*pxwlc 02owr1rellite's speeds.

  A person is standing on a scale in an elevator acce-gy ;v5r ulnv-z2a;o dlerating downward. Compare the reading on the scale to t u5 ;d-nvv ry-2aolg;zhe person's true weight.

  Who was the first person to re/l9 -x0niw)mxy)q 6e m7lgrvn alize that the planets move in elliptical paths aroun gxni-9xl)v le 6y/wr7m0 )mqnd the Sun?

  The speed of Halley's Cv5wsgcp lke a. s3 /:rcgc5-y7omet, while traveling in its elliptical orbit around the - 7.vcagr3gce lpc/s: yks55w Sun,

  Let the average orbital radius of a planet be R. Let the orbital period be T. z j iq(-8dyt3bi2;v)*p myobu What quanv38*z2mb ityd i ; -oqby(jp)utity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a staric*z6 eebufyl3 *fd+1 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 the period of revolution of that new planez cbf1+f le**yei3 6udt be, compared to the Earth's orbital period?

  The average distance fresl 91rm,e9 l3n w4jpf8s3ev zom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average dist ,l1zp84esm9r j3lsf 3w9evenance from the Sun?

State Kepler's laws.ecxkqv)b) tmlc+n,qb4k/+b 8

  List the four fundame8 tn9.u7pnwp;rjr,0mg 1wf3hlei df.ntal forces in nature.

  An object moves with a constant speed of 30 m/s on a x;xp-3u:*ijd6 j kwfv :iak 2sf)nst.circular track of radius 150 m. What is the acceleration ofjxviw 3s)auk2nit*fd sp:k.:6x fj ;- the object?

  The maximum speed around a level curve is 30.0 km/h. w/s6s ow, ruqy) :xtp3 ocf/6n What is the maximum speed around a curve with twice the radius?qw:cpr 6o yf3w/s,sn/to6 )ux (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the pez0r3sv4u( l nesh1ol7rimeter of a bicycle whe(nrzvhsl3ou7 se l 014el of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating a)zm.0ss t qo5zt 5.00 rev/s is located 0.200 m from the axis. What is the centripetal acce5o) s0stq.z mzleration?

  How many revolutions per minute must a circular, rotating space station ouzd8)ahb,st y;*n+ s gf radius +us)*tbz ;a8nh,s ydg1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes iig(19y b4n hv/8ttmk3ed2hv around a 13.7 m radius turn at 96.5 km/h. What is the cenb /h24gtindk vvh8e m(i19 3yttripetal force on the motorcycle?

  A 0.50-kg mass is atta8 qfe zpangr 3dzu 4tad26a;..ched to the end of a 1.0-m string. The system is whirled in a horizontal ci;dpa48 ..3aqteauz gr2 fdnz6 rcular 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 strong string and whirled in a vertical cij/m ;ejs0v9tnrcle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight.m9tjs /n 0ve;j The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical cirvk1 z;2uv gttzeo0 .f:vus8v5cle ofvf: e8o t1gz20 v5svu zv.u;tk 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 point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g 9v v y1wlc(v-iwhen pulling out of tvv1 -9lc wvy(ihe dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in whicdz s4oe rry7:8h the center of the loop is beneath him) of re 7:so8yrd4zradius 3200 m. At the top of his loop 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 weight. ((k2nk4xif3 ko 7cf st What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a spe7c2 4x(3knsk fok(ifted of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horiz,f 9tbwwz6qu0d v/ 2jmontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficient ofd/fw m0tj,q6 vzw 92bu friction between the car's tires and each road surface.)

  A car is negotiating a flat curveab b8ael q4/snazlqag: f7+8 s*)wh8t of radius 50 m with a speed of 20 m/s. The centripetal force provided by fricti:8 sf)q8g/q bhw ta8aln4 * slb+aa7zeon 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 o1 n9 b.ivhkak0f 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to man9.k0h aibv1k ke the turn?

  A car is moving with a constant speed v around a levefvbo2l grc,2tve 9u )( p*9dijl curve. The coefficient of friction between the tires and the rodvo b9)9e2* t rfgi (,vcu2pjlad 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 fo /.1jpon6lhy dr an Olympic bobsled to negotiate a 100-m radiyhj6.n/l 1pod us turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsledbqs,,q:w wk fmfp3c54 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 curve of radius 100 m, banked at an anlw/;zpclkz+h - z1g+ mqxhg5(gle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is ;6t ogk r1-qtnbanked 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 and c24xi1wc)4 8:koc0t: 4lfevoprz m horizontal circle of radius 0.50i4244kf :mpzwrc8l1ndoo:x v0 e ) cct0
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 pi+w8 a5dh,j5 ug.pwzspt area, 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 500 mp,wahu 8.dz+sp5g w5j. (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 ad / kmb.gfcqu4p5 1.y w*dpe-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 Earth, a. e u939crzw*g yym4w:p;mpxh(w8c odue to the Moon; rze :pch3oymca9*. gw m(p48yuxw w9? 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 twom iv2ntl s8:owt(f-hn qu*.m3 masses is F. If the masses are moved to half of their initial distance,ntnq i:l83 v u( smomh*f.w-t2 what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the )6/v 3 ipcotlcSun, at what distance from the Earth will the gravitational foo/) 6 l3ctvpicrces 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,ai8rm asp5 b6df5 o0j $7.4 \times 10^{22} \; kg$ 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 al 6pt uepy.k0d(m ht3ynf f.0n3csf x06b u52vbove the Earth equal to the radius of the Earth. What 2nd.t u30ylmfpv ef(f0.cks 3uthb0p6x6y5 nis her acceleration due to gravity?

  The radius of the Earth is R. At what distan/n qbpc5 fs6a7;i +ucqkxq) u.ce above the Earth's surface will the accele ;s kn.cqucp)x baqfiq7/5u+6ration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dis,sn.cv ubw i1x,ee*b7ks8c0xp c *bi/tance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity ons/snk ec0 pw * .*7 xvii,18cb,ucbebx the surface of Mars, is

  At a distance of 14000 km froms*b c16mra t:k some planet's center, the acceleration of gravity i1rc :bmt *a6sks $32 \; m/s^2$. 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 Eartvlz bd3(pl t0h0;(a3rgv 0dcu h has radius r. If the object is raised to a height of 3r above the Earp;d03z(aultb 0d0h( cv gv3lr th's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chang c ,nwhp0r14 nx+vchs6e when he goes from sea level to an altitude of 5000 m? (The mean radius of tvs 6ph+c ,0h1xr4nwnche 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 thea.wf-en*r0 r b Earth's surfacen-a 0w.br fer*. What is the satellite's weight?

  A spherically symmetric planet has+ z ex6qfkf3(vg*sy.i four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how mufiex v ( y+.fk6q3zs*gch would it weigh on the surface of this planet?

  During a lunar eclipse, jtex6s h,o3dv n+f,0vthe Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a mass o+f6,xnhvet0 vo, jd 3sf $7.36 \times 10^{22} \; kg$; 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 tet8qv93rbx2j( xet0uifs8 6ghe 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 Earth (i.e., it just skimqgrtptgi(35v tj1 2* us the surface of qt 2tu5 1(i*tvr3pj ggthe 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 citk t q+sb0 6m)vm*dd b)n4rhc5rcular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolutiontb0kqb *rhvtdd) 6+n m54)s cm 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 surface of the Ea)du/in.0- taa7,qp wbl lut .srth. It is observed to have a period of 89 min. What is the mass of thel l.i-t /q a),utdwspbu 70n.a Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter of db0 7 7d6:e oedod4yxm6kt8eo$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon ofe o(wzo u+vr03*v -vrv Jupiter 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 circular orbits. Moon A has 4rfdiw) z 9f;du4z+x aorbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. H+dz); ifw4z 9xa4udfrow long does it take moon B to complete an orbit?

  The planet Jupiter isaa6m.h kd) a*lst l9g)lw1c 8i $7.78 \times 10^{11} \; m$ 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 orbi d,gw kjruuf*g 3yxt7c,w ;.ct0/t l,it the Sun once. What is the average distance from Jupiter to the Sun? (The distance ft l;0cg*,7k tutdcigy , ,wjru w.3xf/rom the Earth to the Sun is $1.5 \times 10^{11} \; m$.)