Is it possible for an object c/vi,v.f o*z9p -: ffiw 6azccmoving with a constant speed to accelerate? Explainf.69v*-ff w, czavioizp cc/: .

  Consider a particle moving with constant speed such that its acceleration of / h4dl 7w7s2v okd .7;brsm qp/ythq:zconstant magnitud7d.sqh 2ywps/;o7v:qdzr7t4 h/b mlk e is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the ( -b3*v sajmhltk6 bl, /vytk9direction of the object's veloc,k(kyhb6v* /l9t ltv-3 sjmbaity and acceleration vectors.

  When an object experiences uniform circular moxo m ,w-siy8pm:0wvcw4ra8 ziy6 bz, 2tion, the direction of the acceleration ,am cw -bz6sm y,8:wyvrz 0 xiwio428pis

  Consider a particle moving with constant speewmj-q n ;jk,091acwjid such that its acceleration of constant magnitude is alwayjmqi aww;- 0j9n, 1jkcs perpendicular to its velocity.

  What type of acceleration does an object moving with cons. jt p+ij wt)wysxr)/2tant speed in a circular path s tw rjx)+i2 ytw.)j/pexperience?

  What force is needed to make an 6tdjbz8rejgauk u; )s3.2ne 5object move in a circle?

  When an object experiences uniform circular motil5wvly, --wmf on, the direction of the net force i-v5y m fwwl-,ls

  A roller coaster car 1x1erfc93 t: sxdjk *qwf8w*ht,+d pbpgs 2: eis on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum e2* h *3es1 t w1:x 8 :pdrbtgx+cpk9qjwfd,sfvalue for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track thm.lqe-31h n):ev so yhat 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 lo: nsehe-)y1 lm .oq3hvop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circul igo/v. jy12psar arc until it is going straight up. Just as the plane is at its lowest point,2gjo pi/ 1svy. 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 ra+wui k w50*9l )nuylmtdius $r$ 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 arou,fh xgmax x3ouz 7-do d,2+ix,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 seconxg d,,x2aufdx ,3zo+7hxo- imd time, compared to the first time?

  A car goes around a curve of radius r at a constant spee t:zly2x4se qr.q3sl9d v. Then it goes around a curve of radius 2 x eqlrs2:s493y.lzt qr at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around as x ms(4d 6qolv(1.;lvxrfiw0 banked curve of radius r with speed v. If the road is frictionless due to ice, the carr 0x qlx6.w 1;v(soldv m(sif4 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 bobsled run are banked at the same angle, but oe8fwl q:c so0.ne 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 safe speed on the larger radicf:l08 qewso. us curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, but hc9hwd .rfp usai1j -*rd/u 9*increases 9ha wpi1f*9. us dr/u* hjcd-rupward from 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 moa.b.gt*,ibhuu;dx )hy 2 n6m dving around a circular path to have both centripeab. b,gtiu nu h;)mx6.y2dd*htal and tangential acceleration?

  The gravitational force between two objects is proportionalkz0 h1izg:)ip to

  The gravitational force between two objects is inverse/5 w80dl/qpn ng3kk gcly proportional to

  Two objects attract each other 5:whua0x k (go savw8g3.tj,pgravitationally. If the distance between their centers is cut in half, to:whajt3aggk(v8,sx0 wu5.p he gravitational force

  Two objects, with masselj,(1uk )c b; eu7ms :0bhsgphs $m_{1}$ 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 maswa1vh/a-uh/ .8ircelb e 7(anses $m_{1}$ 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 uhvsi9on:gz/l p:t /gx3 m ./+x3omvqoniversal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moon isbkh l,. c.2tod

  The acceleration of gravity on the Moon is one-sixth what it is onzuc 2g 6f,l0dbo28cyt Earth. An object ofb8cy0o2du 2 tlc,6gzf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from thwn dt yqpojp6t:-5 6y;gtq u9:e Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyonut+n9x b 6 ql (2c85x0sc b7ojmmmqg.bd the pull of Earth's gravity b6qcqbjm05gc 9sm2.bn (+8tuom x7lx?

  Suppose a satellite were orbiting the Earth just above ;hb sd: 04 1j1 , h xj5mfafv+lrfc)r9yizsmf5the surface. What is its centripetal accelerationsdx0zcj5m:al+v jf4,r ysffh 1r h9fi)m5;b1?

  A hypothetical planet has a mass of half that of the Eartg(n vd klzec:1 2h: db/w)/dcdh 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 du) k: n2wzv/cldb/1ddcegh : (de to gravity at the Earth?

  The acceleration of gravity on the M7yjkrtq( hqn1o+xn4ru m.g o4li57u 4oon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the q4j7oygiq5(l 4tr7xkmuuon+.rh1 4n Earth's?

  Two planets have the same surface gravity, but 7 g.w8ojp qlwls5*/x7z +xjct planet B has twice the radius of planet A. If planet A has mass m, what is the majz7s+jq5p .w7xtgl/wcl*x 8o ss of planet B?

  Two planets have the same surface gravity, but planet B has tl6 g*qk78, ks- icilmfwice the mass of planet A. If planet g 8-im lkk*l7qsfi6c, A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circw0:wb0gbp4j+xsbbqz:*yh3j3qk j)h -jen d/ ular orbit (radius r) about a spherical planet (mass M). Which expression gives q*q4 j )b0ejkyw-03bjg/z3 :sbd: xnw+hpb jhthis satellite's orbital velocity?

  Satellite A has twice the maso2wlb gh y cem gz)vp4tm8k 5s,.5i67sw0ch*es of satellite B, and rotates in the same orbit. Compare tm5yoz0p*27 6w lmc, ht4 5 .ikswhc seg)gbv8ehe two satellite's speeds.

  A person is standing on a scale in an elevator avstw00c;t uk/og l-s:ccelerating downward. Compare the reading on the scale to u vogw:k;/ tslc0 -0tsthe person's true weight.

  Who was the first person to realize that the planetast++ i)ce9wrbx:m w2s move in elliptical paths aroundixm rb: c2et+s9)+waw the Sun?

  The speed of Halley's Comet, ))mnp q s3tmcv(kns /2 chbc3(b5r.ggwhile traveling in its elliptical orbit around the S sg 2qt53.n c) 3mpm (cc)bvhbskrng/(un,

  Let the average orbital radius rvqin9m .wem0o 9 dabb9ra9,j 71uk0dof a planet be R. Let the orbital period be T. What quantity is constant for all planets orbiting the Sk9w0jb9 r vo e 91m,.i9aa0bn7durmqdun?

  A planet is discovered to orb6p2maxd1t.aheg.a7r it around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mas2 gm.6.ta 1rdaxh aep7s of our Sun, what will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance pn(wla,):;d7 ,p z8)e e.kkq 2.dugy bpjmfngfrom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-th d (e8kugbw,)pgpa ;y.kefnm, qn p. 7:dz2)ljird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. (q) 2 -vjvwim 4xayixz)/si*z

  List the four fundamental forces in namg;igw3si, ky1xn-k exsi- i 1;q+/au ture.

  An object moves with a constant speed of 30 m/s nvz6 y8vg ddu6a)d3(gtp:tw q gg x9z+zl132ion a circular track of radius 150 m. What is the acceleration of the object?d gg ):8t3atzv6yv3(ig qu2gz1+w6 lxdnp9 zd

  The maximum speed around a level cym5 )ol1 krxe(urve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assumm ol)erx k5y1(e all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of o m6/b js,rby4cp m-r2;c(be cu/: maka bicycle wheel of diameter 70 cm when the bike is movi:,ubr/-/c j;p ob( rcmace4bkysmm26ng 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/sbrt+0kku vhf947jcfw fi7esc01i/ k / is located 0.200 m from the axis. What is the c+77ck1uj cfk0fs/ kb0w i4th/efv r9ientripetal acceleration?

  How many revolutions per minute must a circvae: 3b5 rf.coular, rotating space station of radius 1000 m rotate to produce an oef vc:.35arb artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It go 0/g vyxjo8oitwz /3f6djv48 ves around a 13.7 m radius turn at 96.5 km/h. What is the centripetal for4t oyj8v 8i6zovw0g/dfjx/3vce on the motorcycle?

  A 0.50-kg mass is attached to the en6xnv5p /mo 11zeasm*pgd nm(3d 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 *n g/pv516m1asmmenzd (o3pxmaximum speed of the mass if the string is not to break?

  A stone, of mass m, is attacec6 gu7ozzd usmb9:2:hed 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 this point de:u sb czu 6o7g2m9z:is given by

  A stone, of mass m, is attached to a strong string and whirled in a verticalxf:06geq qqj ; circle of radius r. At the exact q :e6xqq0jgf; 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( yco1 4ow*mhg m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyih*wo moy1(c4 gng?

  A pilot makes an outside vertical loop (in whilhy,r2 (wzq3ex3hv: lch 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-half 2hzqex33wr(h: l y, vlof his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. Wha,1ojp1 tzo 4yft is the minimum radius of curvature that a jet plane's pilot, pullizo4yp1 o ,t1jfng out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m ra *9jmtvlxro xii:f4+1dius horizontal 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 of friction bevfrx 94* io:txl j1+mitween the car's tires and each road surface.)

  A car is negotiating a flat curvggf77w9oc +vs e of radius 50 m with a speed of 20 m/s. The centripetal fo 97f7ggc+ swvorce provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cu;y9*j.suy ow rrve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of frir.wo ysuyj9 ;*ction 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 90s6tq, kc 3 h6ewctqvcoefficient of friction between the tires a36 h6qsv, tt9kcqewc0 nd 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 require :;q4g.rn*i tcya ba8gd for an Olympic bobsled to negotiate a 100-m ra bt.*cn:a;4 riagyq8g dius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on jm (tdxdd4;: ga 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 curve of radius hl2flsr)13:/pgovk9z ygl 1m 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 a1 vc uqstif.;z i1/wa8t $45^{\circ}$. 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 unifoxk3 j /y)5ju+; d ocldyqe5dd5rmly in a horizontal circle of radius 0l;qd d u5cd5oekd)+yx j3yj/5 .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 rah /n7wad)u;xh8s 0vmkei v8 *ite to a speed of 45 m/s in /s vahvn *whi e8du0ikm 78;x)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 con pa*;+ ;od((r7 fuus 4r/ribqj,1 mubs 5ocmvysists 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 Earth, due to e,.8* i dq mer+mgql2bthe Moon? The mass of the Moon mimgq.*el8r 2q+, e dbis $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force b+ - m ad6b *(bj:cpkw:isuloq+etween two masses is F. If the masses are moved to half of their initial distance, what is the gravitational dcau: ib(*lb wj-+m:qpko s6+ attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance fg i 2+58jg5: cghsljbpho( rq0rom the Earth w gqhog50:jgs hjb+58r clp(2iill 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;s;(xxstrjy+p kb7p r c -n(t( 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 above tpli hc6/05hsj8q0m+x8wdw rgj7g/ y zhe Earth equal to the radius of the Earth. What is her j+c 8 p8sl/ wq/hmgzxwj6d5r0 g i0hy7acceleration due to gravity?

  The radius of the Earth is R. At what distance abxtp0h0*zoe5 tove the Earth's surface will the ath0x0e zot*5 pcceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at altebc p:a 4h.2f) rkq) distance above its surface equal to 3 times the radius op atk e))q:lf 4b.c2rhf 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, the acceleration of gravityw ;)u ,3sb/ylv i7mt:ohki 2ks ihksuw23ltysv: ib7k/ ,;o mi )s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface o-(m )tc3wgkzss mt :+xf the Earth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, what is its+)t x(wcm t:3zgms-k s weight?

  By how many newtons does the ,by;jmhbr.k1f q89 pwweight of a 100-kg person change when he goes from sea level to an altitude of 50wb81; .9h rb fymkqj,p00 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius dfve, sl ;x 9 c6u(zfvz0 c:3m1q80 eame/snczr. A satellite of mass 100 kg is at a point 3r above the Earth's surface. What is the9u/ef1n(csm8czvmz dfz6x, 0 l3v;e0q :e csa satellite's weight?

  A spherically symmetric planet has four times the Earth's mass rzb,vydw /ifd) b;),yand twice 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 of this planetb) fzb,ivrdw yy,d;)/?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the / q;cjqi(sp 1k81 (j+xor:pau)pv ethsame line, with cqq:reup( j /1j(;) avx kpi1t+oh8psthe 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 trakc -gyg3 k8iw/nsported 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 the Earth (i.e.n8gw oz (zzg /2k9an1wkct 78r, it just skims the surface of the akw7ocz18rn9/w zk(tg8n gz2 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 ab58 yvuwuieg06k0 fjj )out the Earth (i.e., it just skims the surface of the Earth). How long does it take to make uv0wiu fj)5 k0ejg 86yone revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular z 5pln+ u8qol.zk+qw9l)(g6fu(+n fv c-ivkgorbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius o vuqkl. 9wlzlg oqc+6)+v5n (g( -uf8in kzf+pf the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has +gtrvc40c e n+i(3r7k1 -ytxu 2unmxs 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 Jupiter orbl 27cjxz5)b(3 t/rrco5whcif its 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 w dt* 9g *oomdb:)r.nqorbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. .o9gbd)wn:o*qr dtm* How long does it take moon B to complete an orbit?

  The planet Jupiter i59z bl d(ahy,os $7.78 \times 10^{11} \; m$ 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 orbitax;evc 1)y.rw the Sun once. What is the average distancevw)r. a cx1;ey from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)