Is it possible for an objecuj99o3y,zahokw) uxcx)m1 *a8lqz g.t moving with a constant speed to accelerate? Explain.c)xo1o9 a)y ax9q klh . wm83,zu*zjug

  Consider a particle moving with constant speed such that,l,g 8p nv q/3pbt+xbt its acceleration of constant magnitude is always perpendicular to its velo3, bp+tlx b/tq vgn8p,city.

  An object moves in a cijos8. g*t,p1yukj t;y rcular path at a constant speed. Compare the direction of the object's velocity y g ys1k.;,*t to8jpjuand acceleration vectors.

  When an object experiences uniform circular motion, qg fqa9 v 332bt:e/hwec.p/sn the direction of the accele23 avefs3q9hb/wq e c .nt/:gpration is

  Consider a particle moving witm;lwy )d+a8j lh constant speed such that its acceleration of constant magnitude is always perpendal+)8 l; ywmdjicular to its velocity.

  What type of accelerauvx,g.e;vhs .9p lu+0k) itx/; j0wnsxxg p/ ytion does an object moving with constant speed in a circular path exper.v pk;s/yt/juxih00e lw . +,;ux xgngs9x)p vience?

  What force is needed to make an obkvf+x r:g49ch8dz 4, nevv f/fject move in a circle?

  When an object experiyoapa/l8/ pc((1jv t cences uniform circular motion, the direction of the net forcej/ a(olyc(/t1av8 pcp is

  A roller coaster car is on a tp2r:wy *;qyfo rack 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 minimum value for its ce2 w*yq;yf orp:ntripetal acceleration at this point?

  A roller coaster car (mass = M) is on a tr bd0t1ffy 0z6jack that forms a circular loop (radius = r) in the vertical plane. If the car is to 001d6zf tjbyfjust 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-cir lp;qc0.j,e bynh z3:ocular arc until it is going straight up. Just as the plane is at its lowest pointl3hyb; jq .,p0zo :ecn, 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 radi7 zqa7 z4oavpd4p f uj(3ors:1us $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a cg-a 7 s:e(awf ng2pv9turve 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 goes around the curve ffs 7pa ea-:9gwv ngt2(or the second time, compared to the first time?

  A car goes around a curve of radq zr(w nrppz02 pd/i,(ius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it p, ( qrwpid(/z zrn2p0goes around the second curve, compared to the first?

  A car of mass m goes u z0i;yjv u6q4around a banked curve of radius r with speed v. If the road is fz4qiv6uyu0j ; rictionless 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 an oz1g)k; *ve )yb3wqe bobsled 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 yv3qz*gw;e) nb 1)ke ocurve 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, botdn.g 78tc rqz9cs30hp 2wo 1ut increases upward from the horizontal. Coming around a turn, th9c.83to d cq1tp onwzr s072ghe 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 objee) ks dqz.r 3;/lvtth,ct moving around a circular path to have both centripetal and tan .3klze)t,v;r dths/ qgential acceleration?

  The gravitational forcezt/fy+.ecu8 kcqf(b, ali8 /z between two objects is proportional to

  The gravitational force between two objec; *2ah nxim8ntts is inversely proportional to

  Two objects attract each other gravitationally. If the distance -xgsw f/)rki: between their centers is i-fr/kgwx :s) cut in half, the gravitational force

  Two objects, with mass8po*untruxh0 1 t7 v(xes $m_{1}$ 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 7277k; fhkbi (w rh:icpsznt1$m_{1}$ 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 gravxbw/dg,c3t 3;q -zr. phn8dfpkp-c 5aitation.

  Compared to its mass on the Earth, the mass of an object on 2 8nuaqs sx67bthe Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An obx ;7g*di l7 lq/yy3mnlject of masny*d l y7x/7l3g;iqlms
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away eq 2 0nmmo/jl /gu/on/from the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moontczv*od)z dglm3 ;4h7s ag .vu/a2my -. At what point is it beyond the pull of Earth's7da mc3u tgo2z v ahzmg -vl)ds;.4/*y gravity?

  Suppose a satellite were orbiting the Earth just above the surface. g m/5ons:8 ;v,)(riqzmd)6 g szmaftiWhat is its centripetal acceleration?nf m),s:z)go85t a mzi;s(qvim r gd/6

  A hypothetical planet has a mass of halflo 1by )f dde.bg3h9eb(rt )k0sz3q l9 that of the Earth and a radius of twice that f 9y)h9b1sl3oe. )ldbq03d tbzkger( of the Earth. What is the 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 i83q h6(5ollf ugojz-gs on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Mozgqj5o o38(ulg- l6fh on's mass compared to the Earth's?

  Two planets have the same su t 74x jq-ic7i-:m,av7u+ hcki/op hawrface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what is the m7cw,kq/ ivi muji-:ohp7h4taa xc -+7ass of planet B?

  Two planets have the same surface gravity, but planeta; wr )x5px8nr B has twice the mass of planet nr5w 8p;a)xxrA. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite movinhj f s.sa1bw0-g in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's o. jhf sb0s-1awrbital velocity?

  Satellite A has twice the mass of satellite B, and roxto4x xylc2) 0v yn0l7tates in the same orbit. Compare the two satellite's s) 04nlc 0yxoxvl7t yx2peeds.

  A person is standing on a scale in an elevator accelerating downward. Comp9 icips;, zidin50t, aare the reading on thei tz;nc ad0p5iii,9, s scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical5yj7 ,ol zjn-b nxk/ 0,ymlg4m paths around the x,oz yn5ml,/ j74y lnjm0 gbk-Sun?

  The speed of Halley's Comet, while traveling in its elliep7,7h+h)cdw 8pc4ba z)gl dyptical orbit around the Sunczpd 7,8)h )ghw4cy+ l7 daebp,

  Let the average orbital radi22)zp* nkry80mpjmp nus of a planet be R. Let the orbital period be T. What quantity is constant for all plane)zr0*j282pynpmn m p kts orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy + g2vl6)38t dp eqg-xvzyak4cAndromeda, with the same orbital diameter as td6c-vpy x8qagkve4tg)z2l+3 he 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 defi2 + akqos9sy)e kd*qq-ned as one "astronomical unit+ -qs92ksqykod e*a )q" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.e4.4u k 3bgui3,f d,jcia v,vz

  List the four fundamental fo5i, vh6m2in.ud 5 reoxrces in nature.

  An object moves with a constant speed of 30 m/s on a circular track 8edgs 14iwvb+vp5 l.g of radius 150 m. What is the ac5b g4lp.iegwv8+1dvs celeration of the object?

  The maximum speed around a le+n gzt qtt4yrw)/3k; cvel curve is 30.0 km/h. What is the maximum speed around a curve with twicz+wtk4rt t/3)c n;gqye the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a2 evi n4ax:8xe bicycle wheel of diameter 70 cm when the bike is e:n 8v4iax2xemoving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. Wgcxe +/eg+d5 7-ytmm +vvgu* jhat is th+ygu* d /xme-g+t5v7mcegv+j e centripetal acceleration?

  How many revolutions per minute must a circular, rotaa(slo2(w ibn: 5u*+z arvb(eg8c)tveting space station of radius 1000 m ro:ew u(cz *vei8ao5r(asg+n)bt vb 2( ltate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kzu5/ak 7 p .x/qowxk4bg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal f/bpw 7/ 5xu xa.4kkozqorce on the motorcycle?

  A 0.50-kg mass is attached to the end of a1cne0q79njyl 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 35qn jec7ny 1l900 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 ; lkrrl*9dqe (7qoz9q +lq vp1a vertical circle of radius r. At the exact top of thezor;ver99q(1 + q * lqqdl7lpk 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 to a strong string and whirlb m:kf-: ak.cmed 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 thf ak:-:.mckb mis point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g es qq ow-i 20*okq4vjmkc-e bh)+,e8pwhen pulling out of the dive. What is ehviemp o-*je s-wqkokqq08cb2),4+ the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the9bt:* spg d(l6mvxbrhvr-u*hf,g 63 k center of the loop is beneath hi*brvr x*-btu9v,6pfkh6g( m:hdlgs 3 m) 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?

  The maximum force a pilot can stand is about sev/nr c,1e k6yeoz* ;fl:thyx:ven times his weight. What is the minimum radius of curvature that a je v; tc:*hf6eyre,1ykn/z:lox t plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curvehj**.i rjlfnu 99(oti with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m? (Assume the same coefficii* njlhjo9 u .t9f*(rient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m withqmd42vgn19l idfnhh/v hc11: :eys9v a speed of 20 m/s. The centripetal force provideymh9e:12 1vgi 4 1vvcnns9f/lddqh: hd by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radiusb17qli ,ed eokv37w+ i 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 car to make the turn?e ,d 7b+v1iw3qeo7lki

  A car is moving with a constant speed v around a level cdo,(rv tc n3y)urve. The coefficient of frin tcoy3d,)vr(ction 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 road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a 100d7rd) 3lbs1gy -m rbl7dd)sgyr 31adius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ru3 1r 8y9onz7j vfd-huyn 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 angle1(/nm:44 u9hwaspazax gt9gw of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banke/l an8:q; dfa jpqh9bmd+hjdyf 5qw *jy6;;h6d 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 enl51ijvp2*b ,ken1ru c d of a string is revolving uniformly in a horizontal circle o1 bcp,l2v*ruji1ken 5f 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 uniform rate f:7 otlcnh4v ( ast3x9to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill vctahfs493:( x7otln 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 -is/ 0 4(.uzpaoly*pzvdm y (r* fdw:hof 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 standinl.wc5i dmi 1x:hw8 1rhg on the Earth, due to the Moon?8dl1ih.5xr w:mic 1w h The mass 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 ate ;1;qch bfqy./d)ftltractive force between two masses is F. If the masses are moved to half of their initial distance, what/dcqqy1f;;ftl )eh b. is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from 2q)i6*3yflqa1-cfh ud0e / ps+lgmp doc1l - tthe Earth will the gravitation1ql1ms c h3yp*qgi fatlolcd62)+u 0/f pd --eal 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 is2;b1jrb8 kdvz(sk1) xw l;xnh $7.4 \times 10^{22} \; kg$ 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 di 2zjy: go5u //ze0duwcqnsu 1,stance above the Earth equal to the radius ncdygze zu1jsu:w0, o2q5/ /uof the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will q8 l+ c, gli/jv:h,ph,atpdu- ;s: caqthe pc,,p:- g/aqv;+d,: uis8alj cqlhhtacceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at7i iq9xg .l8eb a distance above its surface equal to 3 times the radius of Mars. The acceleration of ggi8 bleq9.x 7iravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some plarel1pgvojva *(lf9a*60 p5dbnet's center, the acceleration of gravity ipl(a5da p61eb*r j go0l9vf*v 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 surface of the Earth. The Eartgi1j l /z,)qn5rjf t;kh has radius r. If the object is rt,fg qli5n/)1 kjzj; 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-khiid03 4jr0wt g person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earth j4 i0 3rtwi0hdis $6.38 \times 10^{6} \; m$.)

  The Earth has radius gfxy*6c vb+)t 65v dfer. A satellite of mass 100 kg is at a point 3r above the Earth's sb)5fv+6fde t6 cx*y vgurface. What is the satellite's weight?

  A spherically symmetric planet has four t4f3jgn) rgbx0 imes the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, bn x403r)jgfghow much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lx;r cscl.,8jz8lk) ip;f+ue lie on the same line, with the Earth between the Moon and the Sun. The Moon hae kc rsx;p. l8jl8uc;z)+i f,ls 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 transportel z: wmksubn;sr )-3u(d 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 about the Earth (i.e., it jut1u x;g(8omrxst skims the surface of th(orxg 1 u8;txme 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 qj+x;li* lq -rm1 (yzi:fx748q bc oelorbit about the 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 Earxm4*ioci;8 :yjqx-lbzqr+lf e (ql 17th is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth.nv v / udj,n/1;xel9gy It is observed to have a period of 89 min. What is the mass of the Earth? (The mean rad 1/njvd/ngev l9;y, uxius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital dia :o5 (c4s+r x/noveursmeter 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 of6p0;lu5 g q5*v h)frnm-dadkr $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a planet in nearly cm;yj. mh)yw.kwp t rjk19 /*doircular 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 moon B m.pjt)jwky9o1d;rm y k ./*whto complete an orbit?

  The planet Jupiter is x,-p+v,zyso z7+g m2gftg 9g7s e,yq f$7.78 \times 10^{11} \; m$ 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 onco o e1:a1syd;hh -v,cy5m c6hie. What is the average distance from Jupiter to the Sun? (The distance from a5cho oi; dyvc1mehhy-6s:,1the Earth to the Sun is $1.5 \times 10^{11} \; m$.)