Is it possible for an object moving with a constantd9da.4 nzejj 4 speed to accelerate? Explain.z4jan4edd.j 9

  Consider a particle moving with co/o z0 o6bnnv+6 f+co,0jf(hlrkzsk3 gnstant speed such that its acceleration of constant magnitude is always perpendicular to its vfon+6h 6zoc3nls (rvk j gbok0+/ ,fz0elocity.

  An object moves in a circular path at a constant speed. Compznupxd6(34cqaq w ; nu+6q3sqare the direction of the object's velocity and acan4 zs q;xwuq3 d3cp6q(uq+n6celeration vectors.

  When an object experienceswwawvxulm c - 8q8z;5 j4s32pp uniform circular motion, the direction of the acceleration is8jx s5v 2 4lqw3waz;u-8cp pmw

  Consider a particle moving with constant speed such that its acceleration ofl-lbjj *b9 k4 gqij6x, constant magnitude is always perpendicular to its*xkqbbg,j l 6j-4ji9 l velocity.

  What type of acceleration does an objecpva0rt ,dor4 )e) xxt-t moving with constant speed in a circular path experiencerxt-0t ) rvap4dx,eo )?

  What force is needed to make an object move in a ciz,k h; 98j2crlr rd,ptrcle?

  When an object experiences uniform pd p7 5vx86an2nx1z,fxq -okycircular motion, the direction of the net force - 1vf28pay6xdkqo x, p7nzx n5is

  A roller coaster car is onbl(erbb7 n 0p7 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 minimr b7(bpn e07blum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a cir 4t 1 74xotn* njl*ymiqt3mc/f,4uucucular loop (radiusm474ycumijfxn4tc* n quo tul *1t,/3 = 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 speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until f: :v6u+xgy (efe:pac it is going straight up. Just as the plane is at its lowest point, the force ona(cxg::fveu +6e p:fy 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;d3; zulzdg q(dius $r$ 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. 8 f+kt abco:q2Then 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 c:+a2o c8kf qbturve 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 iqe0h7h 7amxjr403m 8/xeg nbgoes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it go07 /ine7ej43gx qxr hhb8m 0maes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r c (8x unqz7(xf8ai1zi with speed v. If the road is frictionless due to ice, the car cauixc(axnq(z88 f 1zi7 n 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 ba xmr1 *t5*o9ka cv4owcnked at the same angle, but one has twice the 4591 vk* ccxowtm o*arradius 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 radius curve?

  The banking angle in a turn on the Olympic bobsled track ijtb 6ea 1bq.2 dfdk-i8s not constant, but increases upward from the horizontal. Coming around a turn, the bobslj.a 8fitq6kbd- de2b1ed 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 arounvao)x;q5: sqk d a circular path to have both centripetal and tange:5s)v k aqoqx;ntial acceleration?

  The gravitational force between two objects is prop kl5zxkk+0kjqi qs .+hc8)s 2bortional to

  The gravitational force between two objects is inversely proportional tosr,*g0h6n+2ceuus ik

  Two objects attract each other gravitationally. If the disnv bc1dm8- ,z7zm.*funco0vl .gv h f.tance between their centers is cut in half, the gravitational.lcvv0zmh,bdn 8f.fcvo1u-7. *n gm z force

  Two objects, with massesf vial*px6nnv--(n :p $m_{1}$ 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 maf f99qu8gnrmzp 2j 92qsses $m_{1}$ 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 gravitatio .8q1 9)t leizrq6ak8mp/lefbn.

  Compared to its mass on the Earth, th: iak.up42nq-ujy(0gb 5s hree mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on z8v3 j4gxbk 49.ctrrq +wda0hEarth. An object of mar4ht43c jz8 qw.vag kbd rx90+ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Eart oe3,yuf/ cweigxz 6)ixziv72t9iv9*h's surface, the rocket's weight

  A spaceship is traveling to the Moon. At r,,jh9z rcq eez al()/what point is it beyond the pull of Earth's g9erhq) r,,c(/zje azlravity?

  Suppose a satellite were orbijgfezb(7*p 1 nting the Earth just above the surface. What is its centripetal acceleration? 7e fb*zn1gpj(

  A hypothetical planet has a mass of half tha h 0 ,nc(nysv-xt)pa:a;i x.odt of the Earth and a radius of twice that of the Earth. What is :)xd.tp -n canx,o(i ; syahv0the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it g2sqfzj*-kl3) x8oau is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth*az l3)-gxfos kquj82 's?

  Two planets have the same surface grrwex2,q2 rse fc:lu+23f w:yyzj +,rjavity, but planet B has twice the radius of planet A. Ife xf,22j qf,3+j:wry2s wyrrue +zlc: planet A has mass m, what is the mass of planet B?

  Two planets have the jhxb59d /o bi.same surface gravity, but planet B has twice the mass of planet A. If planet A ha.5/bo j xdhib9s radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) a ogg:;xm jw+ kz/rzn)2bout a spherical planet (mass M). Which expressio ;+/g2zwm :kgj)zornxn gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same orbi1 7vhms )ko wp,uw4nj.j/ +dyev8pz(nt. Compare the two sdjjnp7w/ 1hu)vmnoev + wk .8z4s yp(,atellite's speeds.

  A person is standing on a scale in an elevator accelerating d:lnr8 9so6v ozownward. Compare the reading on the scale to the pez r:osvlno8 96rson's true weight.

  Who was the first person to realize that the planes q l54ffn09ants move in elliptical paths aroun 95fqan sl0nf4d the Sun?

  The speed of Halley's Comet, while traveling in its elliptity9ji 38 z +d n g7ov26lk:l7bw2:hfsept kop*cal orbit around the Sujbg:ykt o *e7 dnki8shzp +o:329tlpfw v2l 76n,

  Let the average orbital radius of a planet be R. Lez2 wje5tc(z,ag2 j pcb*og 16it the orbital period be T. What quantity igcpcji a 1ot6bj zge,*(wz252s constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in a1 ln84myurd;gt q rae8+lw71the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sun, what will the d78r ml g l1traun148w ;eya+qperiod 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 one "astronomic vp+w16x( ts)9j1cfysrn vy 4pal unit" (AU). An avws1+x(j yr py1)t9c4f vp6snsteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.69tej5z(w gl/hoy 5eg

  List the four fundamental fr- wic7e4jw p( zf5uk:orces in nature.

  An object moves with a constant speed of 30 m/s on a ci8r eay,x 1gk2wx+n2(rt ak-9 bspy;t ircular track of radius 150 m. What is the accypx -8e;ra1k9sa x t22g(+n, bt iykrweleration of the object?

  The maximum speed around a level curve is1 v7tqpf 5 /;vht-ubha 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unch15 q-p;/uv7bfhh tavt anged.)

  What is the centripetal acceleratia* 7wnunw +k7fon of a point on the perimeter of a bicycle wheel of diamete+*fk7wn an7w ur 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locatedh65vk 8n vn96tmuse-k.x/ qbgs5 s-l y 0.200 m from the axis. What isg t vk emk./-sb-5y85xnlv9q6nus s6h the centripetal acceleration?

  How many revolutions per minute must a circula6 9kyd0oxx90hn 8d fatr, rotating space station of radius 1000 m rotate to produce an artifi ntk6fd9 0a8hdoy9x0 xcial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It g0(sqz zvul18s9 7qpuk oes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorcyu(zql9qz80vp k7 uss1cle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. Tq5t jxf()(is wm v9g;xhe system is whirled in a horizontal circular path. If the maximsfvi9 ;qtm( j(5 gw)xxum 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 in a vertica0d xu :dhf,z-rp9)vxhl 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 :, dzp) h09- xvdfxrhuthis point is given by

  A stone, of mass m, isf/jbfdsl,*k62k9hq x attached to a strong string and whirled in a vertical circle of ra9, qs2*b kd6 hfkjlxf/dius 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 point is given by

  A jet plane flying 600 m/s experience+b1w 6ok*es m9tl7mnys an acceleration of 4g when pulling out of the 9l bte *ok6nmy+17smwdive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in snc:e64 l 543bpm bbuo6 co3uea7d.qpwhich the center of the loop is beneath him) of ru das ecbb 4b6o5pequo7mn3p:.6 3l c4adius 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 seven times his weight. Whagwxga(:/i+ r gmad-4s t is the minimum radius of curvature that a jet plane's pilgwd(-g4s ixm+/a agr :ot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-mfl(nm24o q 8b)q mb-sj71n1njvynn6y radius horizontal curve with the tires on the verge o-)8 1mj6n4 y b(1nnvbjnql o2nys f7qmf 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 surface.)

  A car is negotiating a3g r5+:z uiuqa-z v8t+*eeqwb flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by fricti ezu+w *3g qq8b tui+-zvrea:5on 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 speed of 1 5t5d9o r0usrj4 m/s. What must be the minimum coeffi0rs55r t9ojducient 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;su dcjws0db3cqg/ s3e m)//z a level curve. The coefficient of friction between the tirsbjcmucd 3/s)qzde0ws3 /g/;es and 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 required for an Olympic bobslemrch .) *oh-vbd to negotiate a 100-m radius turn at 35 m/h)h-ocb r. *mvs without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankerbf iu:vp1k6-rw .cs +d 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, bangv 6j1g et fe j wy*p3-8f4iiekh8g(i8ked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atriw5,mqbns z1t:9id8 $45^{\circ}$. 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 6 g rb9llfq6bw 2o.pm8of a string is revolving uniformly in a horizontal circpof rm2gq9.lb686lbwle 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 uniuj/gqa p om,y-a8.tsn0,.it yform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill yg q/8syi,,tt . jma0.n-auop 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 pro 4j qwt1o+k4v-tk2jcqzof-i6a zk9a ,ton 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 standine t4e fix2mw3+g on the Earth, due to the Moon? The mass of the eime3 4t2f+xw 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 the mvtuw *7 l;c2 /gshvulr cqv3+35d)j uwasses are moved tuscvw;lvwj3 duv3c/5+*2gtl) uh rq7 o half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Ear0/sjp7v9mbqo6gh ef * th toward the Sun, at what distance from the Earth will the oqmhfpvs b0e/ 79*6 jggravitational 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 9(*mjusr-9 w7d n +qn -hhofhdis $7.4 \times 10^{22} \; kg$ 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 3i7 a fgb6j,ygabove the Earth equal to the radius of the Earth. What is her acceleratiog 3jgifb,a76 yn due to gravity?

  The radius of the Earth is R. At what dist1hlx5tk/b *0xam 4 .9e /fw qwm,einrrance above the Earth's surface will the accelerationr r fekw4.e/wb 95lqnixmx/ 1t0,* hma of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance aboe:j;jmmirxf(* dfsd + -8 ot+r(osyr;ve its surface equal to 3 times the radius of Mars. The acceleration oi t*dmdr+r+- ;m8sr:fjxe ; os((yojff gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km f9uos t 59*2 kx/m hyeseof::bgrom some planet's center, the acceleration of gravity iseb 5fuom9s:o : /ghyksx 9et*2 $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface ofs16(z rci pm wz2d;bvt9, 0wkt the Earth. The Earth has radius r. If the object is raised to a heidm6wc10 trz(;9w,zisb v2tpk ght of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg per(em/l bnz;)3 ;wpwgfp son change when he goes from sea level to an altitude of 500gpw;);(emfwp b /3 nzl0 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is atmx-vxasiy-73 d ea5:o a point 3r above the Earth's surface. What is the satellit ayio- -d7x: xmev3as5e's weight?

  A spherically symmetric pm+edo+0/fny ;ty xj (rlanet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth,;/xr+ m +oy(ytefjn0d how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all(;s0u5 t9bmu*d s1sp tclg-p a lie on the same line, with the Earth between the Moon and the Sun. 9t- asbsc01p;(dlm *ps 5u gtu 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 transpotr96qg z-enen 4a k,-drted 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 abob lzswd37/x) bt-i*by ut the Earth (i.e., it just skims the surface of the Earth). What is the speed of the sateyl/x3bzdbbt7) wis- *llite? (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 t bq+. dej30o(g4t8,y;r6v:x -tekof nqxp mfjhe surface of the E r0 :tv-qqgyfn4jjo kxm o3+e;f(e8d p6.bxt, arth). How long does it take to make one revolution 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 surfackl )m/ai9 (auge of the Earth. It is observed to have a period of 89 min. 9u(k)imlga a/ 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 orrrj-4hqzfj:desoa z*.h/ 07 0btfof ,bital 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 planet with a radius of;bf1,ye.wf 5as ox 4tg5 kri5v $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly circular orb+jfv+rr7 q.gxthv 0( oits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to compleq(ov hr .7rg+0j +tvfxte one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is:l xovvazn433 5tahqag: ;uu. $7.78 \times 10^{11} \; m$ 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 /9buk y.qud6.anb;4iq xqi0r z3 pey2 12 years to orbit the Sun once. What is the average distance from Jupiter to n3.9yu6rauzxbb/ 0pkq qi d;24.qieythe Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)