Is it possible for an object moving with 5pa)n( lev;r+ (qxk)xv u-cqna constant speed to accelerate? Explain )(qvxqn+n 5axkclrv);e(up- .

  Consider a particle moving with constant speed such that its acceleration ofsy.e8/yvmrq*q z ) pyw.)v b-u constant magnitude is always perpendicuzqvp.yyyb wq mv)u-*e)/r8.slar to its velocity.

  An object moves in a circular jwa ksdxw*c1ou/; ,j+ path at a constant speed. Compare the direction of the object's velocity and accelerationsadj;xwcj +1k*/uo,w vectors.

  When an object experiences uniform circular motion, 2b j)7su+ i2bfql+ py pj)5atpthe direction of the acceleration is)22u papi5p+bf7 tj )s+yblqj

  Consider a particle moving with constant speedu dku *ri8m40o h7wa5-hzi*sf such that its acceleration of constant magnitude is always pe07dm s4r8zoii* a*u kwhh-u5frpendicular to its velocity.

  What type of acceleration does an object moving with constant sn5juup8 po t40;od.bg7/fki x peed in a circular path experien.i 5o 4ppd/0ukgof ;jbtx 8n7uce?

  What force is needed to make an object move in akhqh ;baaz) :m/j0 5bq circle?

  When an object experiences uniform circular mop1*c*k +qylp z3mch ,ytion, the direction of the net force ipy3y+phq1mlz kc ,*c *s

  A roller coaster car is on a track that forms ax3b jqq..h5 q:cc ba1mg4 aok7 circular loop in the vertical plane. If the hq:qmbj qx.oc5g371 a . 4abkccar 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 on a track that forms a circu i6nd 4)js,2 dxc d,p4,swqirrlar loop (radius = r) in the vertical plane. If thxc sni, )s4j2pi,r qd4dw d6r,e 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 point?

  A pilot executes a vertical dive then follows a se7e0(x wh ,vtbymi-circular arc until it is going straight up. Just 7t0x ,weh bvy(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 of lpi:h5ey 1yp*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 conuu;aoauvgo6 fli0-: */ccm-lstant 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, coa l cvu6-/ 0uo-*fco i;al:mugmpared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goes arol)zjwr6e/2u je r6mf2und a curve of radius 2r at speed 2v. What is the centripetjw/jmr662f e) u2e zlral force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked ci-:i ij7eg;s ihm52p kp x2y1v c.jl6uurve of radius r with speed v. If the road is fricti: iuv 5p. h6gxl2iim 7k2e1y;ip-jscjonless 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 bobslep zdzz i2x68/znz,c ;wd run are banked at the same angle, but one 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 spc 8wn6z2i ;p, /zxzzzdeed on the larger radius curve?

  The banking angle in a turn on the Olympic bobs ,9hifnacvdq5 3got- 6y1rj b9xig 2f/led track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "clinadhj-/5f1i9 i62grxbvg9 cto3 yq, fmb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object movingml,:2kkqhj b7 around a circular path to have both centripetal and:kmlqj2 7h,b k tangential acceleration?

  The gravitational force between two objects is proportjv8+8h ofrlo ciklfv/, u,mn)ur 6q15ional to

  The gravitational force between two objects is inversely proporbc 5gf*nx2. yttional to

  Two objects attract each other gravitationally. *r 9jbhfx 2m7/xv : y6roto4sf If the distance between their centers is cut in hal/r9xx6 v4:b 7 rjtsy*fh2mof of, the gravitational force

  Two objects, with massesujxm 5lh gfb.m knz +o-os ),(-w 9onrg4h-7kx $m_{1}$ 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 mas9mv yoer,+4 5q m9tztdses $m_{1}$ 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 univers-rhpdp-zn 5(/u bt zn7al gravitation.

  Compared to its mass on the Earth, the mass of an object onar;wd9w.wsl7ac cmc 3)gl5 y+ the Moon is

  The acceleration of gravitjh u 1gnb-y.tdz-8w-dy on the Moon is one-sixth what it is on Earth. An object o.w1d -zdb-8 y gu-jnhtf mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away fro8 3bnlq jl;s2fkoet:+m the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At b5cyu8ij6dkt 2-ddml uos6n; a- .w9bwhat point is it beyond the pull of Earth's gravu65ob-j89dc 6i2. dm-yknut aw bl d;sity?

  Suppose a satellite were orbitin,i: .o nkj7 e5xo.+yegh7vijvg the Earth just above the surface. What is its centripetal acceleratoo ,vi nh.jxi: j+.v g5e77yekion?

  A hypothetical planet has a mass of half that of the Earth andkq1bosq,.2k a 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 the E 1qq,2.askb okarth?

  The acceleration of gravity on the Moon is one-sixth what it is on Eartj c++qksde-4 ;3jvfmc h. The radius of the Moon is one-fourth that of the mcqs 3cf 4edjjvk+-+; Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same s m)-i i, 0bmof7scn2mkurface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the mass of planet B?b0cikn- mmo7s,im2 f )

  Two planets have the same surface gravity, but planet B has te8cized//. na wice the mass of planet A. If planet A has radid8e in/a .ec/zus r, what is the radius of planet B?

  Consider a small satellite moving in a cirlv 31 2ef7uvfvrmgh( 5cular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellitemv7(15heu 3flrv2vfg's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the lo0r/v( p34-qge cc qlsame orbit. Compare3(q 4le0-cv cqo lprg/ the two satellite's speeds.

  A person is standing on a scale in an eleve1k,np nvq3,sj5;q pmator accelerating downward. Compare the readin pm;p5e vkq1,jn3sq,ng on the scale to the person's true weight.

  Who was the first person to realize tbuzy3,s. k ngca-or45hat the planets move in elliptical paths aroc4n obk-r5y3 . z,guasund the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit around the iktrjoc / ; . hh*uib/9v1rhq6Sun,u/* ho/. i19btrhjkr 6cqh;iv

  Let the average orbital radius of a plan/ tuz-f/a(.uuh fr5,ja vv0 chet be R. Let the orbital period be T. Whatf5.0tz -uvu uhfa jvc//r(ah, quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbitbu,a0z5 7 euql around a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that sta bu7zq0au 5l,er 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 the Sun imr;hi+qvpb*q5-vool+8i,bhj+ h u z:4q9 tue s defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the ,*iv9u 4 mpqh8ho5jibq bvo+;lh+-q ze:+ur tasteroid's average distance from the Sun?

State Kepler's laws.9gkgdxdrplt-f r:79 +pm4c 9 y

  List the four fundamental forces iq p/bk ym73,h4d1 q8zkh1hfg+rb q9mfn nature.

  An object moves with a constant spoy5dxecn h4 yg9l(2 1jeed of 30 m/s on a circular track of radius 150 m. What is the acceleration of the 14j 9nolc(dy 2h gyxe5object?

  The maximum speed around a g*pb/ld2um( s ur0/fkvx 3s*l level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radl0s*/*u 3dmb2fkvs/p g ux(r lius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the zg65cegf :jhllr23gs7ep (,k perimeter of a bicycle wheel of dk (efgh gp2:jlg36res z cl57,iameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 r 9 26hta1stnqa-ag:njev/s is located 0.200 m from the axis. What is the1q:6- jgs2tan9n taha centripetal acceleration?

  How many revolutions per minute must a circular, roz2vkk1*nf (bxtating space station of radius 1000 m rotate to produce an artificial v(nkbxkz *1f2gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turnz8sr78(qcaw g/bllam e4( wh 9w/ztj 2 at 96.5 km/h. What is the centripetal force(a 7(ze9r8g84/bqcw2tlmh saj/zwlw on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirv9b lj 9c c(rvv*w6bbti:wv) 2led in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum speed of the mass if the string is6btvw l(: cc9bw9b*vjrv)v i2 not to break?

  A stone, of mass m, is attached to a strong string and wz/(a:ir db.) hmonu9c.c ,:1vy q/wg +uwyplwhirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 tiu: my.ucqnw.o r, /wzpdv(c+hy i9 b1wla):g/mes the stone's weight. The stone's speed at this point is given by

  A stone, of mass m, ii*; 5 widt*tlps attached to a strong string and whirled in a vertical circle of 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 poin *ilt;dt5ip* wt is given by

  A jet plane flying 600 m/s experiences an acceleratio rkyv;p7bz+83d5 3k, gol zuzun of 4g when pulling out of the dive. What isuvu+dlkbkg, 8;7pr o yzz35 3z the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the ,;r qjg pch7q.jww6d:center of the loop is beneath him) of ;rdcw:qjjg7. qhw, p6 radius 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 stjm.q5vy3lt )4scl: peven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate attl3)lc.:t v54yspjqm a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tii 9lrzj629 9bge ,r b qphi;hef:ok19ires on the verge of slipping. How fast can this car round a second curve of radiusf ijzi or9 1ebepk:rb l92i9;q6,h h9g 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 with aib v.m)-l1miq o j35oa speed of 20 m/s. The centripet3. qo1mba)ljv5i m -oial 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 speetpia)dd .ltmny grr67-6 - t-fd of 14 m/s. What must be the mi t.-ng- lar6 t6t7fy-dm)drp inimum coefficient 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. 4q*jbpe3* /rv*rh tf xm ,vqhv5rp*o, The coefficient of 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 roavq** p5e**o q4rr3xtpmhvfbhj,/r ,vd?

  What minimum banking angle is required forj pwoy+e a,)d* an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Igna j*+) ydp,oweore friction.)

  A horizontal curve on a bobsled runsl b:g6e+ azq.vq)zy-zv1 7 cf 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 / lo2trwfyc1 oii u(+2100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at lq 232oppq 76htc9pvq $45^{\circ}$. 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 a horizontan 6cz+f+vpc6w l circl+ +z6p cvfwc6ne 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 at a un u7co; uu:6w ke(6uomziform rate to a spzw me;uck:o u6 u(u6o7eed of 45 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 consists of a pruq6gaq 4e (gp,oton 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 toqj01v2nl 3z pi the Moon? The mass of the Moon is 0l3ivnj zq1 p2$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force be h glc1 j1w:-wxo)tna4tween two masses is F. If the masses are moved to half ofwglot 1 1a4:xjn)chw- their initial distance, what is the gravitational attractive force?

  For a spacecraft goingf l6 ;eplvyc63 from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the 6fly3; 6v clepEarth 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 +gdhl ufueqi,7 9 8eq*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 the Earth; rhq9lj tug7)w4f*un t-bmn, equal to the radius of the Earth. What is her acceleration due7ml )4t nw*9;btnqgfr-,j uuh to gravity?

  The radius of the Earth is R. At what 70ugxojxvu3 ) distance above the Earth's surface will the accelex3uj0x uovg)7 ration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars.d/c jrh8lto4 at a distance above its surface equal to 3 times the radius olh4to jcd./ 8rf 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 accel3 us40qzomc5o yj/d4 keration of gravity iy0o34c m5zdu4sqk oj/ 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 surfacezbx v0*dt,m w, 3iht9x of the Earth. The Earth has radius r. If th3 vx0zdw,,tm9 h*bitxe 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 person change when he goes frbd )l jjgai5;rfm934i om sea level to an altitude of 5000 m? (The mean radiufm 5j g3)iajbrdl;49 is of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 ,yhk (nyusl 11b2)qi kkg is at a point 3r above the Earth'syik2k hbq),unsy 11 l( surface. What is the satellite's weight?

  A spherically symmetric planet has four times thdu6v0 ui y(k8te Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on thi06dv8yuuk( te surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on5v:lzhrh fb i ,g6oq/: the same line, with the Earth between the Moon and the Sun. /hqoh::f vb,g5 lrzi6 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 the Moq:eowu ;)wyocrry:. *on.
(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 ju0c+yed; k*k wo/,31btct) 3yvewj eimst skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Eartekyy,d 3ewt*vbc/c)o1i ;3t+ w me0jkh is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about th 7el2ly xynm30+ rvrf*s)t+ gke Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth is +7fy*nl g +2k 3rrymxlv) es0t$6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. gtt3vqk9c /6lei)q(l:z l /wo It is observed to have a period of 89 min. What is the masscv/k/t9eqi3 (l)zl qtlgw6 o: of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupibn :xot x3./yn33lsvzfi c-/1sq2 (v*dl mdpw ter, 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 Jupiter orbits thednd6 *(;jxpy ;y q6wpl 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 i8ovtv bh.t(g3 n nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes v.h8vtb(3 ogt20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i4 -( rp9owhn4dr gw)so rv(n2bs $7.78 \times 10^{11} \; m$ 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-kp yc31* 3lhtncs7m y. What is the average distance from Jupiter to the Sun? (The distanc13npy3ms c -l7ch*tk ye from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)