Is it possible for a3 f:r*ksry+kfmci3 5p-l8 nrlgu m 0,kn object moving with a constant speed to accelerate? Explaif :r*cryg -0sku 3pi klk5,m8rl3nm f+n.

  Consider a particle moving with constant speed such tjgpq6:lv;c; 6.dww jm3h1k p *2hjwaw hat its acceleration of constant magnitude is.1 6 p m*hc3wl qv;jgwakj;hp6jwd2:w always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the dire rbk,jx3w, r5nc3ln2b ction of the objkj2nrc ,l ,5bb3 3wxrnect's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the accele+tnaa (ugi:mhugf:2( a.zwq 5 ratio2q +ngfa(gwu um :th(:z 5aia.n is

  Consider a particle moving with constant -d + -o:/1lvo.m dbadp+xi5gru vm -ksspeed such that its acceleration of constant magnitude5 1s: ./ddb+pmkaoxdmr--l +ogi -vuv is always perpendicular to its velocity.

  What type of acceleration does an o:bkm. u a*d5*jqbpyt:bject moving with constant speed in a circular*tby:*5k:p bmj dauq. path experience?

  What force is needed to make an o0 rfocl4hszgo9w+*;sbject move in a circle?

  When an object experi tk*b6:o+jxnx ences uniform circular motion, the direction of the net force xnj6x*k: bt+ ois

  A roller coaster car is on a trac yd/yyyh t5hp(dw4b ;*vi hu;j, f94iqk that forms a circular loop in the vertical plane. If the car is to just maintain f4(w, yhhjdp /tq v5iy 9*i;u;h4dbyycontact 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 ff alu*n;t61cs1(vqr2 7afqkborms a circular loop (radius = r) in the vertical plane. If the car is to just mainta2kb ;alav6(fcn*sq11f 7u qrtin 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 semi-circular arc until it i b76szfx d8h9or9b h,is going straight up. Just as the plane is at its lowest point, the force hfdrbxo6s, z89b 97ih 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 curvfo.)t8dykw i+3kgo;ye of radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a cur38xurvhbh.p*hy9dp n gs8: 1lve of radius r at a constant 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 goesy.:hpu1l8v9*hx p8ds hnb3gr around the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant siwo3ren3d 975) orfwkakk(: g peed v. Then it goes around a curve of ro(rfka 57 :3e ki)3gk9w wonrdadius 2r 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 a banked curve of radius r withmmpc60/l 4m ry speed v. If the road is frictionless due to ice, the car can s mlp6/ryc m04mtill 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 th e z (z)k-*h*:hkofda nvs*(sye 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 speed on the largkz s*:)kh(zeyonav* s -d( hf*er radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constar e:5-f)vr*i1a0s1v ialzu sant, but increases upward from the horizontal. C 1leisv)ai0avs- fr5u*: z1r aoming 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 moving arou guwdk9fgd;owk m)98u;*y+3uevne:b nd a circular path to have both centripetal and tangential accm+;bo;k*:k9uf9g e w )gw8 devnuduy3eleration?

  The gravitational force between two object1m) gom)jnjhj / kcv tu./aa( 56kq7eps is proportional to

  The gravitational force between tw (:f fvqvtrhono1wn4 h w2h;*,o objects is inversely proportional to

  Two objects attract each ov-xe 6z3 +i8h.q mzwkcther gravitationally. If the distance between their centers is cut in half, the gravitational fo+v . z wqxz3-ehm68kicrce

  Two objects, with masse( 3swabwufk:2 s $m_{1}$ 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 masex0ky2yqfu/ ,t 9j8x, itg bl2ses $m_{1}$ 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 gravitati aeo sfw0i:2x/on.

  Compared to its mass on the Earth, the mass of an object on the Moon ye-dkb6/fct 9is

  The acceleration of gravity on the Moow)-dt; ok;b4,nkaf.ur xlhg. k+x d-an is one-sixth what it is on Earth. An object bkdkax-; l 4 w ,g ndkr-)f.u.;otx+ahof mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Eartha0zd).,;.c*cj eeo rdgp ayi,'s surface, the rocket's weight

  A spaceship is traveling to the Moon. At z64yii s) )bruwhat point is it beyond the pull of Earth'siy)s4br ui) z6 gravity?

  Suppose a satellite hm5/ks( ldl,:qbe yi1were orbiting the Earth just above the surface. What is its centripetal adqll5b(e 1iyks/ m:h,cceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twicey)qe8 q 6* p7t1kgqplzjtj t 7y*a.+cg that of the Earth. What is the acceleration due to gravit8tqp 1 y7c*e+kj7qj.6gq*tlzyta)g p y on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity9b 8xbhx0d 3e5h3welt on the Moon is one-sixth what it is on Earth. The radius of the Moon is onhldeb8hx w390x3e t 5be-fourth that 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 tvb1la ,j zs9j0q6rg7pm2y f9g u ch1b)wice the radius of planet A. If planet A has mass m, whah06,jm1 g z)j9v1bfg9lacru p2bq ys7t is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of d1sh pm +)ipjfic wb/2.9stek.. ux4lplanet A. If planet A has ppb. )ii wh.ue/sdm1f4.lcjxstk92+ radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a s+p ;0psox4js 8j,bdglpherical planet (mass M). Which expression gives this satellite's oxlg80ds+4 bpo,s; p jjrbital velocity?

  Satellite A has twice the mass of satellite B, and rotates h.h0a1 1vid7j)qtt ge in the same orbit. Compare the two satelihdg) qet0hav 1tj.17lite's speeds.

  A person is standing on a scale in an elevator acceleratinq/f y vc/ronet.a, 8e-g downward. Compare the reading on trft.ve/ q -nc,ae/o8y he scale to the person's true weight.

  Who was the first person to realize that sps 3a+xowg06 * qh1fx-yfn8fthe planets move in elliptical paths around the Su01o+spaw 6hxfn y8q-xf *3f sgn?

  The speed of Halley's Comet, while trave6b j)rhqa5p y35jxs /a.rgho 1ling in its elliptical orbit around the Sun) p sy6ajx.15obgrraq hh/35j,

  Let the average orbital radius of a plakz0m yk40u; br-h1qnud jr8v(net be R. Let the orbital period be T. What q 0by4k-ndujvhmrz0 ukr8 1q ;(uantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witgd2z3 y-l rnf0vyc 0*n./d tqth 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 planet be, co y.tyd/c dq32 -0vnf0 ltnr*gzmpared to the Earth's orbital period?

  The average distance from the Earth to the (d* ihnv3vvx* 0:zwj mSun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. Whvh*zv* 3w(mxj invd0:at is the asteroid's average distance from the Sun?

State Kepler's laws. r0o9nx5n 9pup

  List the four fundamental forces in natpsyr9 69 ,adxxnv1oy7 ure.

  An object moves with a constant speed of 30 m/s on a circular track of radiur+ h8(kmy4qqdz 1hda* s 150 m. What imq*d8 (q1+dkr h 4ahyzs the acceleration of the object?

  The maximum speed around )8wfbg*ba7 u,k+g rafa level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchana ,ff)b8 7 gagbwuk*r+ged.)

  What is the centripetal acceleration of a poiv*s*psjc brr 8.-lv/qnt on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s .8svjlpqb-* v*r r/cs?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ltl,p2et+omx )q 3i5 qaxis. What is the centripetal accelerat3i)meqp2q olltt+,x 5 ion?

  How many revolutions per mina/gk,j*6ojnmqvq /w t;0fr ;fqj(spek+c42 wute must a circular, rotating space station of radius 1000 m rotate to produce an artificiq qkkj20, ;f*m/ rjvwne 6owp(f/ac;4gs+tq jal gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13. ozfz71z zv9 f+c29s*vtxu2ax7 m radius turn at 96.5 km/h. Whatfu7tfc+z2ozzvs2* 9xx v9 az1 is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to t 1 aouj(t au:7cls1)vehe end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand 1 u o :(aljveacs)1u7tis 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 *mg.tz7uk/x n07xfvg and whirled in a vertical circle of ram7gx gnuk0 f/z7 *.xvtdius 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 is given by

  A stone, of mass m, is atxt0.j +r5 ki8hh4 y):ruunvoitached 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 r tvx0)h8.+5ukii:h4y ronj u 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 4) dneqq)r /do3g when pulling out of the divoe )/3r ndqqd)e. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical v/0bi2f wv:zd 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. How fast is he going?vvif /:20wzbd

  The maximum force a pilot can stand is about seven t)kn 70owddv t:v+d( luimes his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out :l 0ddvdnwtko+ (uv)7 of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/ zx0rrm+g uo4r*9 7h qa(9fhahs rounds an 80-m 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 the same coefficient of friction between the car's tires and each road su az 4(+a7m0 o*ruf9h hxgr9hrqrface.)

  A car is negotiating a flat curve of radius 50 m with a speemy9dnui9an x1)ks s*;) xk1a/yag (a nd of 20 m/s. The centripetal force providenk)1ns aia; 9(a1 nd9kyusg/xy*xam)d by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flatr2,omy0 0dx w0l)pgd l curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the cax wol,2p0lmy0dr 0dg)r to make the turn?

  A car is moving with a constant speed ( u+ nv7llvowgg.q5z ,(lps-dia 9 a8cv around a level curve. The coefficient of friction between the tires and tdvp .o(g+s85zlgc(lnwaqv9- ui l ,a7he 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 required for an Olympic bobsled to 1kwyp:*fzb6v hy 1wl0 ut6 re:negotiate a 100-m radius turn at 35 m/s without skidding? (Ig1wwvh e6: fluz0r6bkyy*: 1ptnore friction.)

  A horizontal curve on abq)cgt*m ltjpps 175.xw-i35 peu :9zfi. id c 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 100 m, bankerh ct x3 rse8mh)+mw48d at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80usd3 of /q*7id7lq1dl m is 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 e6n+ i;fmg(x0 new oa-o.z3.aews5k wnnd of a string is revolving uniformly in a horizontal circle of radius 6-n(i oo;s0.w5exwk anm.g afn z 3ew+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,*,g 7 4hhc4usxv1vkov a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circulc*441sh,gu 7xv vokvhar 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 consio*ui/f p: zq7x l 6uq-g/9ibyzsts 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 gravitati+(u-j c*8bj7cbju; s dmd.khopkm.a )onal force on a 70-kg person standing on the Earth, due to the Moon? The mass of the Mom .;chd7k p) k+msca(j.bdu*-jo 8bj uon 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 the masses ar/bs*vv 3gb8pq e moved to half ofvv/s*pqgb 83 b their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward+(e9 /kr8b qpwil:lke the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the(lp lere:/ki k+ 8wb9q 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 at i98/yltk) 2vyxlz( $7.4 \times 10^{22} \; kg$ 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 disiuavrd 1() 0gctance above the Earth equal to the radius of the Earth. What is her ac0a1g) iudv(crceleration due to gravity?

  The radius of the Earbqoqd v2 3+x jbpv::y.th is R. At what distance above the Earth's surface will t:x3 .b2o vyqbj+ vp:qdhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encirclesznaz; 5p;x7w 1rh 6zwk Mars at a distance above its surface equal to 3 times the radius of Mars. The accelerarzz17knz6w;x 5 ha ;pwtion 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 accelezzpyc: i1 gua0p/ik4e k zs906ration of gravity is 0zep 91p0:ckazs kig64zyui/ $32 \; m/s^2$. 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 Ear6s/s,e(p1pyas6md*qk 8 rypi th. The Earth has radius r. If the object is raised to a heightyepr( *8qp,6kpsadyssm 1/6i 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 9:if4 cuyuzhx0e3i4c6s j t4ifrom sea level to an altitude of 5000 m? (The mean radius of the Earth ii:uey6i40349u4sxjh iz tc fc s $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is a q cnv8j trmu+)d7+hi3dk,m o1t a point 3r above the Earth's surface. What is the satellict, r+1j73 d mq +n)hkmiuovd8te's weight?

  A spherically symmetric planet has four times the Earth's mass and q1lucz 6jez 2pgy7n1, twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on thjlc6gz nuq, 1pz1e 72ye surface of this planet?

  During a lunar eclipse, t9 : e5hq4nuzw4j)2fs h9qmq;htew/ efhe Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon ha9h:zs)h q j;teq 42/9mhf4funee 5qwws 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 trannvf/g ) a4rm2qsported 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 8upfdc5+ +eapcircular orbit about the Earth (i.e., it just skims the surf +ceapp+d58uf ace of the 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 about the Earth (i.e., it just skims t7hb ud3 l0y3.ye38i.y slsxoeg8q0o*bfo y0 jhe surface of the Earth). How long does it take to make one revolu7s3f* 0 y obu o i.d lo08e3qhye.x8y3ybsg0ljtion around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abovej;:upl tb 0o+y 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 of the Earth:ujlpt ;o0by + is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamete7t3h6iqom3e k r 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 planet with a radiusph* t,ktd/(9oq8uoq,tq, 3wx zvet+i of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a plan/j0n +ldmdxc -ueko0m yv 9+3ket in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moonv j x90/mkd0 c ekmyn+o+-ld3u B to complete an orbit?

  The planet Jupiter iy ooc aa.9/fr3s $7.78 \times 10^{11} \; m$ 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 S(uf imd r7 a5:we46dct1hf:qj un once. What is the average distance from Jupiter to trf(6 dqd :af :icht7mw5e14ju he Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)