Is it possible for an object moving with a constant speed to accelerat-1 s7rlt ab5x/b0ks (7eu el dwz2ca7ae? Explain.dw(7 z0-b uxerskal1s2l e5b7 a/c7at

  Consider a particle moving with constant speed such that its acceleration of c6or5l +hna :6r7nq hfwrnv1 x9onstant rv7nh ohr 6lxqw n69f1:5r+anmagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a q 9 +d,xeonxb)x0o4ksconstant speed. Compare the direction of the object's velxqb0,ekxnx4s )9 o+doocity and acceleration vectors.

  When an object experiences uniform circulpsii 12s9 qxwadh8d+7ar motion, the direction of the acceleratio2 i8+ai1w xhd s9qdsp7n is

  Consider a particle moving with constant speed s*4jmgaj knq,, uch that its acceleration of constant magnitude is always pna,k q, *jmgj4erpendicular to its velocity.

  What type of acceleration r izcmcj.*; )kf02q wxdoes an object moving with constant speed in a circular path experience?*c.0 w)rqckizmjf x 2;

  What force is needed to make an object mov0c5 lvv o0q)yvl 7hezozor.9ule09s8e in a circle?

  When an object experiences .- )5/nt;klplq uya,u1 nor leuniform circular motion, the direction of the net forceq kell-u u l.p)n;1/,r5noyat is

  A roller coaster car is on a track t5+x4s lmlo6gc 3lz;iohat forms a circular loop in the vertical plane. If thgli;m36lz+x45 so co le car 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 formsm;js +q7q2)y-btdyk v 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 spe;+qbky- )dvtmy q7 2sjed at that point?

  A pilot executes a verti2i .s /m45knbfnynk3k cal dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forcemisk./ 4kbnnk2nyf35 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 cu a htv/x1 qc:dehwhfoh5.yr 5z y0(-6trve 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 ii- k8emk /3ja)7*ca8jjp6lk5ac ol c gm1-rw 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 secoae/gia )kp-58l 1jw mca *-clomcjk3i jr786knd time, compared to the first time?

  A car goes around a curve ofspihj g2kfi o3jg5kh4*- qn9/9 wo9pn radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centr p hfi/kpw4qj gh9 2 9isjn593-kno*goipetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked t- n++wgvv792ypxe+x:yohw qcurve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal componew9 o+v2evxx gy qy:p7h+n-t w+nt 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, +57iv l11aw urtpi/w;twzn j:but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for+np;/t1:ui7w5 w1rvz aj iltw the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, but i,k+ga ,xb8 cfxncreases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb thef, +gx xck,8ba wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving l+/p;g*seni3tg r.jnaround a circular path to have both centripetal i3. jpltges;+nn r g/*and tangential acceleration?

  The gravitational force between two objects is e:hi.tby,ca k he1.r0proportional to

  The gravitational force bet cwe(5s 1yjv4.xv0h3 xsf+vkn ween two objects is inversely proportional to

  Two objects attract each otheygu x 861xxhuah,:5 jfr gravitationally. If the distance between their centers i uyhu,f6g:x5 ax8xj h1s cut in half, the gravitational force

  Two objects, with masses w9 89oma,9dcl+rxi fx$m_{1}$ 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,b8;t *yqbo-,edhckf -x8sqs $m_{1}$ 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 gr 28w)lyzi37o nggf b;cavitation.

  Compared to its mass on the Eartmzz*5u(x)zud d4vb) pl(g2r th, the mass of an object on the Moon is

  The acceleration of gravity on the Mo+fx*ak /:vkwq on is one-sixth what it is on Earth. An objec f+kkaqw/*xv:t of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away f5yd b8n88la ferom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what poinff+8gbnnn8j6 x3th6k t is it beyond the pull of Earth's gravitb+6g8 xn83nt nfjh6fky?

  Suppose a satellite were orbiting the E jqo6wh0-p6d barth just above the surface. What is its centripetal0whq 6d-bjp6o acceleration?

  A hypothetical planet has a mass fkh-h.tvgu.+o ak0 3 rof half 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 g, the acckfh-a03t+.kurvh.o g eleration due to gravity at the Earth?

  The acceleration of gravity on the Moon ipi3f*0 cbo op7am4s(ps one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What i0ic3 p( s*7omop4 pafbs the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but plaa./5d+op +fgf ,f yd6c-zkzk/dca kn :net B has twice the radius of planet A. If planet A has mass m, what is dfynk k/z c,pz6f -gk/d.5ad+:oa+cfthe mass of planet B?

  Two planets have the same surface gravity, bu r*3u,ii:a1hs gjhra (m/ nw1st planet B has twice the mass of planet A. If planet A haa:n/j hua,(shig1 1rmiwrs3* s radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbyia-:cn*nv3 fi::ub8 u3zxq u it (radius r) about a spherical planet (mass M)ic:zy *iuu-x8a bvfn:u 33nq:. Which expression gives this satellite's orbital velocity?

  Satellite A has twice the massy zsraa3zbqv +a(-8f0 of satellite B, and rotates in the same orbit. Compare the two satellite's sp-qy b3(v rfa saza0z8+eeds.

  A person is standing on a scale in an elevator acg6 +g nb*l9uhdq/urw:celerating downward. Compare the readinhugnbrg 9:wulq*6/d +g on the scale to the person's true weight.

  Who was the first person to realize tz f4jc a9tae4(hat the planets move in elliptical paths around the S4azj9fc4e ta(un?

  The speed of Halley's Comet, while traveling in its ellipcn 7+z;aj +dmkr.kx3y tical orbit around the Sun+kjzkcn7 ;ydmxra.+3,

  Let the average orbital radius of a planet be R. Let t028txa lt9 aeshe orbital period be T. What quantity is constant for ax2l9at8 t e0asll planets orbiting the Sun?

  A planet is discovered t.mx c u8(w,;iqf 8nxaoo orbit around a star in the galaxy Andromeda, with the same orbital8 onxwfu ;c(mxqai8 ,. 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 planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as 8pkdr)bo*btkiqa 6 neqb5(,z( / qx 6pone "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance frop5tz qabpnd*(,rqoq(b8/x kie)k6 6 bm the Sun?

State Kepler's laws.1:w lh-lnr5e6weo ,nb

  List the four fundamental forces aixftp+cu+e 6h+7 yu7in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiu v2ww j+ ds0dx:n2lii:s 150 m. Whax w0+ddwvns:ljii 2 2:t is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h.gj+x9l /o7b ;e8 o(a8 qdvctyu-h zz*i What is the maximum speed aroun zbc 7+ehq9loiavu o;d8t(gy-8 */xjzd a curve with twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleinua *5bl,; jj10 lpceration of a point on the perimeter of a bicycle wheel of dc1 l peinaj5;,0* lujbiameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is loft2hzkue3lm, 3h/3 7sm s0qzocated 0.200 m from the axis. What is the l ,oh7/u3f2hk0st3z 3mqse mzcentripetal acceleration?

  How many revolutions per minute must a circn .y qq15lr8t0w/yd s.t3)yiiybp- dhular, rotating space station of radius 1000 m rotate to producd01w d)i.byhqs nlti5 tqyr3y- p/y.8e an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. I8t,fg c6km)( p3e qtqnt goes around a 13.7 m radius turn at 96.5 km/h. What is the centripe t(qmqc)g ne3, tkpf68tal force on the motorcycle?

  A 0.50-kg mass is attached to the end od 16g:jdb-t.n ggd(vf f a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum n j d6vgd(1tg:-fdgb. 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 nct+wdh :ebw*dk 89r(in a vertical circle of radius r. At the exact top of the b(k9:+ e*wcrdh dt8nw 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 c*j bvj1d r:) ;m b7lfviu3/wvto 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 tim :) vrwljfubjdvim1cv/37b*;es the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 mbt, pjyo k+ u2ssd,n2:0e en0q/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the planeo2,eten dqb+,0 jy:usn 2sk0p is flying?

  A pilot makes an outside vertical loop (in which the ce4c lqt90h uzc7nter of the loop is beneath him) of radius 3200 m. At tth4z97q0u c lche 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 uzh-v/. p tm0eabout seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical divpmzevt/- h0u.e, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m qi:w:xtn,v6r radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume,rntvw 6q:x i: the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a fl 8x81z rvtod)5gctu:3)r;+hqt fcscmat curve of radius 50 m with a speed of 20 m/s. The centripetal forcv3xc:8odt;)8zt+cmq1 crr )gfh5s t ue 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 radiuz,v tq-j5fr 22wj o1pus 50 m at a speed of 14 m/s. What must be the minimum coefficient o j1or jp25, qtvf2-wuzf 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 cur rm;. nads8)c(iyo*fave. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car isc sa8)( yd r.naifm*;o to stay on the road?

  What minimum banking exe +:zhj u.onbbv+59 angle is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skiddinhb.+5ezn9 o+ux j: bveg? (Ignore friction.)

  A horizontal curve on a bobsled rc3gat9 z lv57)fsqj y7un 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 angle of t8 g9,y/ jet8n 6clen6e3ap rj$45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atcxm 6uu hj) :g,5rt ;v8wjro*k $45^{\circ}$. 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 horizonm j7k2 tc ko9xct9hzqe))h/2 rtal circle of radius 0./rkkz99jomx7t)tch2ce 2) hq500
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 w 1s5le0p(ew6gk -reza speed of 45 m/s in 15 s, moving on a circular (z01-k lgwrps w6e5ee 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 proton of m7;)lp(qt(jblxdy5v ,p-xqhm *lpve)ass $1.67 \times 10^{-27} \; kg$ 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-xqhd-45zbb eu.5rg m8oq53 x6bn:f2t q df6nhkg person standing on the Earth, due to the Moon? The mass of the Moon is d5d mo xg2qfb4-nbf5zt 8h5b6xe6u.qhnr :q3$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractiveb5 dpctilvj;2hu*.0d) ob;l e force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitacpd; bvt*iej ; 02lbh.du )ol5tional attractive force?

  For a spacecraft going from the Earth toward the Sun, at w qt d29j(.mczdhat distance from the Earth will the gravitational forces due to tj 29dqm c(zt.dhe 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 Moontv 4*vx(ghj +uygg0zl; q qa/. 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 ab i ml5r,v(xk2uazm2(k ove the Earth equal to the radius of the Earth. What iskx2av, mk(m 2ruli5(z her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surfaci k 0 f(i 6e4f8yg+jxp3pprq7d83wkxi e will the accele 8 6q3ip7+fkd4xpi3x pfjgrke 0yi w8(ration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal toerc4 d8gf4s) l 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity o ce4gsl8d fr)4n the surface of Mars, is

  At a distance of 14000 km from some planetmaa zhzwx; .c1-.r,vt's center, the acceleration of gravity is rz1;ax mzh-v. a.,ctw$32 \; m/s^2$. 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 radiusa2i e tm;;t6py r. If the object is raisede;2p6 tm aiyt; to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100s: /z+cat)ve pst y( ,uu,unm0-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the m zt,t( n,+sac )/u:u0eypsuv 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 the El: c4oslo4 dm/arth's surface. What is/4lsmo l4od:c the satellite's weight?

  A spherically symmetri6w + 4yqcqb 3/4bemv5tza9bvb c planet has four times the Earth's mass and twice its radius. If a jar of peanut butter tqb 4mcz 93qw+a6vb5b/by4 veweighs 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 on tyn *dv oe+r iq-vc6v1,he same line, with the Earth between the Mdvrv1-i *6qycn eov+, oon 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 transported to th g px00 hu0rvlr)+-z7extsl5a e 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 orbi5q84 n1lonldgt7ugp.m25 qu+dop iv ,t about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the sanm p 5lu7 q,up.q2l+1ogni8tv 45ddgotellite? (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 nm;hded )arm-8 esu 8qdk :t/0skims the surface of the Earth). How long does it take to make one revolt8s-0 narddm; u) /kdqme:e8hution 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 Earth. It ib5a24iqariq,6 xc h/ ts observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earti,t2c6h xra /45b qaqih is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter,egh vnm+f:)5,0 ksnka 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 the playaou y39d ivo*0-pzfya qd:2;net 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.i /)vgc+ci ,)-exl fhn v-pda,qx:2 kf Moon A has orbital radius r, and moon B has orbital radius 4r. din vfivk))-,: pc,+xlfge-ahq /2cx Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is+tpx2du+50v6 ja gv7zuijjcn98 h q/d $7.78 \times 10^{11} \; m$ 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 h u5,n31rd*n;pkd(;i+i j/gfa ekhbi. What is the average distance from Jupiter tf, ;jid a/gu(d+i e1n 5hrhibk;nk3* po the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)