Is it possible for an object moving with a constant swua3:v :d,bwzs a vf vm2l/g-3epw( t1peed to accelerate? Explain.bw:wsa gt(v3p mlew/vv: a,-z1u2d 3 f

  Consider a particle moving with const3+5a; las ikedant speed such that its acceleration of constant magnitude is always perpendicular to its velo;edkasli +5a3city.

  An object moves in a circu p,1+5zcwu p8/ hfqcj rsfz.n1lar path at a constant speed. Compare the direction of the object's velocity and accelefwqcu,p+fhzz .8r 5 /js11pcnration vectors.

  When an object experiences uniformd6luvqs4aq.dn 5zw+ -xq;lm1 u2r2qy circular motion, the direction of the acceleration iaqu;d2dy6-zq.umx1 s 2r v5wl l q4n+qs

  Consider a particle moving with constant speed suys- /4r3k 9haj *ls7 egkze ul)6zq )iun0gsg*ch that its acceleration of constant magnitude yl0s) u l6e7*/rz9-*ih3ag sjg)egzq uk4n ks is always perpendicular to its velocity.

  What type of acceleration does an object moving with constant speed10 a-ipk kg*i20mdggv in a circular path experience? *i0kgka i-gm10v dg2p

  What force is needed to make an t b.zfa254 p.zs9cb0c ,qwaykobject move in a circle?

  When an object experiences unifn8tq c- ,rscir;4cmo)orm circular motion, the direction of the net forn-iorr8t mc cqc;)s4, ce is

  A roller coaster car is on a track that forms a circular loop in the verticalbeli/q x4+as( rc nd+5 plan nbqxad rc++es5(il/4e. If the 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 trq4v utv(mwhtw7 4i9, xack that forms a circular loop (radius = r) in the verticalwt vhtui q (,mw9x44v7 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 point?

  A pilot executes a verticalas-i26a8imx xy6qsxof o(7 r; dive then follows a semi-circular arc until it is going straight up. Just as the pi m x26ro7s6fa oy;ix(8x-a sqlane 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 radiuvjb6l9/1)d o aatb9wkw;huc ;qiq 2-is $r$ 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 ik,ekdc 9; 4snp4d ud-vq,0co lt goes around the same curve at half of the or;kdc4dvn9,-q l40o dske,cupiginal speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it gx t(j 7 q6x7 fbdvf;0xi4vwx7qoes around a curve of radius 2r at speed 2v. What is vqx q6b7ft7x0d4(xx;w vj 7ifthe centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius rfr+hzn(qjsz5(fa l,5 with speed v. If the road is frictionless due to ice, the car cas z(f+ qz anhf,r55l(jn 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 /6s 1d5fjlfkkangle, 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. Whafd6slj1kf/ k 5t is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not d:vs;8 2mzm;h4uis siconstant, but increases upward from the horizontal. Coming around a turn, the bos8 2shui; mdzm;v:4si bsled 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 moving around a circdeq89fh4y:tz ular path to have both centripet f:hd8yqt9ze4al and tangential acceleration?

  The gravitational force between two objects isz dc (+mrhzo8d3h j/nqg+53dy proportional to

  The gravitational force between two objects is inversely proportional uyb 2(tmn1*sw/qcf6d to

  Two objects attract each other p:4szq afxa/ r p3 qu22l.0acngravitationally. If the distance between their centers is cut in half, the gravi. l fcxaaz q2rp/p:230s4aqu ntational force

  Two objects, with masses r0yckpy69n.a$m_{1}$ 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 mas)sfqo h;a6j yhrhkb/z6v9d 5 4ses $m_{1}$ 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 unive;rmh j.xy j eggpe-eg(a+l91,rsal gravitation.

  Compared to its mass on the Earth, thex8.lno/w l 3d:ae3rle mass of an object on the Moon is

  The acceleration of gravity o yhtk+0mpp31vf)6c wntpb( 5in the Moon is one-sixth what it is on Earth. An objectkn0tywp pi6 3) pv m(hfc1t5b+ of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfa9 ydeupj7hqc-(.) yiwce, the rocket's weight

  A spaceship is traveling to t3kbfu*po7 t , 4oogdsvfzx( wu85mb( +he Moon. At what point is it beyond the pull of Earth's gravityuos bgpoo+( m57ux(,d 4wvftf3k*8zb?

  Suppose a satellite were orbiting the Earth just above the .) met7+az*g5ktdiwh64my a nsurface. What is its centrip.mt5tyzk i 6d 74ea)ha *wmng+etal acceleration?

  A hypothetical planet has a mass of half that of the Eart, pxnux )f0ee k6-t:;i dltn0ph and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms ;efekntupd6 x0nxp,-i0tl ):of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what/,jcp fy rree,w rd6+71a,hvi it is on Earth. The radius of the Moon is one-fourth thadha7prr/j , fr1,y6we+ i,ecvt of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the)tp.1dyy4dtv*htl ) 3dbo fi6 radius of planet A. If planet A hho f3y1tybip.6ddl*ttd )4v )as mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B tmnhcg;if4b3e j j/0q2(dw* e has twice the mass of planet A. If planet A has radius r, what fjj em0dhw cbn2i*gt e3; 4(/qis the radius of planet B?

  Consider a small satelmrd 2w) m8hwy*lite moving in a circular orbit (radius r) about a spherical planet (mass M). Wyh 2)dww *m8rmhich expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in0tt1ewp19kbr(,e ,pfbek- l d the same orbit. Compare rp9ptbk1w e( d,fl ,e0-etk b1the two satellite's speeds.

  A person is standing on a scale in h 9mx3zzh6ud;;g ;rlyig2 c3 rh37vy vq4 hoc0an elevator accelerating downward. Compare the reading onoycu03 q; h6;z;vm2h7r 3vgcg9h4dihz3rxly the scale to the person's true weight.

  Who was the first person to realn x((uxg7.r.sy5cpr x+cuk + bize that the planets move in elliptical paths around t+xuc7s( .pr yb nc5.gkx+ ur(xhe Sun?

  The speed of Halley's Comet, while traveling in its elliptical ohg c);w5u 3bi0qspvzi t 9)y+rrbit around the Sun, +vq it;wgsbr 3pyz) u90hi5c)

  Let the average orbital radi7+iate 8mz9b xel8 vko/ 6jc)rus of a planet be R. Let the orbital period be T. What quantity is constant for all pltxil/ ca 6zoke8 8+)mev 79brjanets orbiting the Sun?

  A planet is discovered to orbit around a star in the ,im lko-0bo x;galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that smx obl; 0iko,-tar 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 f4jp9n4k nlf1 hrom 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 distance 9 hfl4pn4njk1 from the Sun?

State Kepler's laws..qi, +m5g;c5wgyzuxpdvx .to t+ml75

  List the four fundamental forces in natu229 jo/l7gpgt6o hav xre.

  An object moves with a constant speed of 30 m/s on a cirz /kq 36y3xr 8sldo+rdcular track of radius 150 m. What is the acceleration of the rz8od/q 6ysrl33kxd+object?

  The maximum speed around a leve myz84mgaqjm q5 9:p-ql curve is 30.0 km/h. What is the maximum speed around a curve with twice tmqgjz myq9p-am 48:5qhe radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleratiotb2aa;9fdkx(r2*mg+ +n rol j iu-6uk 1hlg5 pn of a point on the perimeter of a bicycle wheel of diame*25 n2ap gmlto+lgj6xiabfh d+( r19r;u k- kuter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s eqac7-sv)d g: vvws xqd -*9b3is located 0.200 m from the axis. What is the centripetbaxvs) - d3qdc s-eqvg*w7:v9al acceleration?

  How many revolutions per minute must a circn nxj9n-h5l)v ular, rotating space station of radius 1000 m rotate to produce an art) x5vln- jnhn9ificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It go+1bz o qc-;klmes around a 13.7 m radius turn at 96.5 zo+-1bl; qkcmkm/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Tqf ftu xd9du18xo7;a ,k)0hja he system is whirled 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 thefu81o7aqd0h,k9j fa xt d)xu; string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vertical))yf f1 ;(bew /mk+r;cilhrvj 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 sp;r;)flibwjv (1km)/y+h frceeed at this point is given by

  A stone, of mass m, is attached to a strong string and wh d 2bn4)*hukyq weyf6b5;q uk7irled 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 we)h 5kqfdby;n4by 6 2uuw q7e*kight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g ,bopm0s ngbx -iu.89g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyipxs0u-8,ign bo b mg.9ng?

  A pilot makes an outside vertical/pd4 vub 8ti*/ v-gwpi loop (in which 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 of his normal weight big/v8pt vd i*uw/p4-. How fast is he going?

  The maximum force a pilot can stand is about se bfj t74+jb/ dzrm3j7vven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a jj7m/v3 tb7d +rzjbf 4vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radiusv2g4fq :wf f3z horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assuffqw :42g fzv3me 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 a sug s,8b:gv q;npeed of 20 m/s. The centripetal fos8u,b qv :g;ngrce 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 s7ys9w i*r8kd l5 2cwfypeed of 14 m/s. What must be *yldskyf7 wi 8wrc952 the minimum 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 cuznu 8a4q :b7 ei*nnwmi5n1b .drve. 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 mban i *:uidznew.b n578 1qn4on the road?

  What minimum banking angle is required for an Olympigo,e/w()lu+c5 sc jz tc bobsled to negotiate a 100-m radius turn at 3j/wleoc ) gcstz(5,u+5 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run; r(*z;wtcivab qo9/5ufzea 8 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 anykxyck yg i ;- 0l; )gd63ezuzf4as)(jgle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is liz*qkr7f;w* z io ;u-banked 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 .6:,xkvdbtamw2eo cpl:r :-d uniformly in a horizontal circle of radius 0.50:mw:2r.: l6-dec,pdavo tkbx 0
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 uniformi4(wr ,9o(ugwhwcup 9zbpyi- 3 (gm4e rate to a speed of 45 m/s in 15 s, moving on a circularpuwyzi4beupwirg oc3( 99-(, 4hwgm( 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 consiskwh-0wr6e)b jts 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 /f;yf+a:q tt)jkpvjs j5*zb9v;a;k hthe Moon? The masy;5tv)+;a 9kfj: /*p tajszkfbq;vhjs 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 masses is F. If the0fuk06,lnw2*idn a vo .gair8 masses are moved t u, o2rw 0iin6.l0*gvd8n aafko half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance 2fkuvo m a.g72qs/a7hfrom the Earth will the gravitational forces due to the Sun and th.qa2h7/2 fs7a ovukgme 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 iv vin:lap;4) 6gho4y:z 3av gds $7.4 \times 10^{22} \; kg$ 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 *61axd3nw1bayir b3) uvi kpmj,3or; above the Earth equal to the radius of the Earth. r*m 31i;d n6iokua3,j)yaw pbv13brxWhat is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's suabk ewp 9l mlj95(hzrk+a/*(rlz(f)hrface will the acceleratizbz9 jeh9r r/(m ll+ lfaw(ah)(p 5kk*on of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfacf4wa/)k*dk po95u bpj e equal to 3 times the radius of Mars. The accelera)a5bwk kdj 9ufppo4*/tion of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 kmt+lrfp 0f-jij2uqvs2 j+1- bt from some planet's center, the acceleration of gravity istfp j2t1 v2rb+si0+l -jf jqu- $32 \; m/s^2$. 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 radiu *hho1z :c9usis r. If the object is raised to a height of 3r abo:1uih* 9zcoshve the Earth's surface, what is its weight?

  By how many newtons does the wey0pw csn:4vvom2bmxq; ),* 6jsdsa s :ight of a 100-kg person change when he goes from sea level to an alaj;d6s: swvx)v:b 4cqsp 2 ,sn 0omm*ytitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of+qf9fkq sww.* mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's we* wwq9fsf q.k+ight?

  A spherically symmetric planet has (n:vt+lqp.y89gpy u kfour times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on gp nlyq9p(ytu.v8+k:the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and mf-t / ybrp0mt;zb8, kSun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a m0r-yktf; zt8, bm/pmbass 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 trfd+5( 3sli mqvansported 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 abou:isc j2l5fhi1 y3 jei4t the Earth (i.e., it just skims the surface of the Earth). What is the speed of the s:hfjij2 1yci 345ile satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit abom:3sm/q-n wd/h/ bzxc ut the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revcnh /wq-/ z dx3:mmbs/olution 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 E. yvjc7;rfhu:arth. It is of j.uh7vcr;:ybserved to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbizrphbbem1( lb61ui 16 tal 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 p 4m9qogkw*6w nvw5+evoa8:7u8 t lcq alanet 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 circg-svknh;xpti p - d6.mn:,3uq ular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. H;uk.mit6- s 3xvgp dh nn,qp:-ow long does it take moon B to complete an orbit?

  The planet Jupiter isr4: ;i+vs:xaex0vjd x $7.78 \times 10^{11} \; m$ 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 x-scomvzv *:6ij)n,r the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to tmi)n*sxvrjz: -,oc v6he Sun is $1.5 \times 10^{11} \; m$.)