Is it possible for an object moving with a constant speed to accelerate? Explaifo7x d)wek -u01g1kw un.dfk) kwg1u-0w7oe u 1x

  Consider a particle moving with consts jkqzo3( 34qz*o0j qqant speed such that its acceleration of constant magnitude is always perpendicular to itj3z(qkq0j4z 3qos q o*s velocity.

  An object moves in a circular path at a cz(y n4o4:oeed1ts,1.a ka w)asq-rkgonstant speed. Compare the direction of the object's velocity and acceleration vecwtyo zao 4)nq,sk(1gaesae kr.4 -d:1tors.

  When an object experiences uniform circular motion, the direction od rl 4sisamd.; s e.,k.0r4uqyf the acceleration rdlsyd0.e,i.4.;rs4u s mqkais

  Consider a particle mod++k 7 kadey k /9ddbdxp:fs*.ving with constant speed such that its acceleration of con.:kdedyds79k+pa+k d f *x/dbstant magnitude is always perpendicular to its velocity.

  What type of acceleration does an object movitaig4,n )bv) ywzjb;/-ig sj9ng with constant speed in a circular path experiencvgi-9 z,jnasyjig4 bwb; /) )te?

  What force is neededq 35gisl en 1cvhua::cu :al5) to make an object move in a circle?

  When an object experiences uniform circular mw)rhi.hmmei ) gt /)8hotion, the direction of the net forcgwii8m)h/rt hme ) .h)e is

  A roller coaster car is on a track that forms a circular lo ;w: u4byl/jh8a5rs nlop in the vertical plane. If the car is to just maintain contact with track at the tjws4ylrun;:/lbah 5 8 op 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 forms a circu ck335fscmc-2 0ezlnc lar loop (radius = r) in the vertical plane. If the car is to just maintain contact with the n-5 c0sc2fkzlcec3m3track 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 is gok l8k)i0ywg9w ing straight up. Just as the plak 9l08gwwyi )kne 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 radiducce *y oe7q6(4n+peus $r$ 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 -d1+ouef q nn7tpvr 7yucu853it 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 second time, compared to the first timen ocy3 f77dnv +eu8 5tu1upqr-?

  A car goes around a cur((7+f ch d ,yymyhwp;fve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripethcwfy, ((fydy7h + pm;al 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 with speed v. If the wlsg q4:2g(-lxj(c ap road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the nor2(q lacpjsw(xg-: 4gl mal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled ru83zcfr7ee9pnj*zonq 4q of+ .n 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 curve is v. What is the safe sp7 qr*jnn9p8f .3fcez+z 4eooqeed on the larger radius curve?

  The banking angle in a turn on the Olymz/xksr hd87 o(pic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," thex k hros78z(d/n go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circula+p)xmniji 6uc be3,+pr path to have both centripetal pxmjp, +i bic)63 +neuand tangential acceleration?

  The gravitational force betw f t0z3w(qi:;9hx n;mz0x.vin k/gmzoeen two objects is proportional to

  The gravitational force between two objects is inversenxg.(0 5rx.fk yu phx*ly proportional to

  Two objects attract each other gravitationally. If the distance betweetlz-8e .xauvq6,gw 4sn their centers is cut in half, tv-xgz qu8,6 w l.stae4he gravitational force

  Two objects, with masvhc2:a( wvz; e;g9pioses $m_{1}$ 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 gheebes,*b3g55i t 6bh5l1 s2a,pxkx $m_{1}$ 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 uh rr9p)l fh(; ve)skju:t;*yiniversal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Moon iew;dw)xu j-/sj - 0 ,45i kcpg+saphiws

  The acceleration of gravity on the Moohz3r3wy: i 1zjdbd/(c n is one-sixth what it is on Earth. An object of mac1whd : z/3(idy jrbz3ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's weight5wonytloe p3 )8k(qc 0

  A spaceship is trave4mk) pj) tyhydsh6 0zg.03kwlling to the Moon. At what point is it beyond the pull of Earth's grkypytls0k wg6h3. )dm0hjz4) avity?

  Suppose a satellite wer x,q9r7iu1n)vb ful*re orbiting the Earth just above the surface. What is its c97ru ,v*x 1)nr quflbientripetal acceleration?

  A hypothetical planet has a mass of hal xcn-4uksd2t1f 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, usn d42ck-t1xthe acceleration due to gravity at the Earth?

  The acceleration of grc ei8kup;)mm.mgb8t8 avity on the Moon is one-sixth what it is on Earth. The radius of thmk)etm 88. ;pcmibgu8e Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the (8.,nm p z6x(s gnoumksame surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, wha mmgz 6.8k(pxs on(n,ut is the mass of planet B?

  Two planets have the same surface gravity,h(: o7ut4 (hozszp-a3w qdb1x but planet B has twice the mass of planet A.d :qosx (tohu(bz7 pw314h- za If planet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circun;b7ts z b87jblar orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orb87btjbzn;b 7sital velocity?

  Satellite A has twice the mass of satellite B, and rotateso *xrb)8xu0 : erya4kt in the same orbit. Comparer0ryt*k8x b:x)eua4 o the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward.qx1cywen +(mp8p * xdxg/o8 y: Compare the reading on the scale to the pery/cqw8gm+*yp(dpn:8 oxxex 1son's true weight.

  Who was the first person to realize that the planetsv3zt7hv;q *pt move in elliptical paths arou pz*7vt3qtv;hnd the Sun?

  The speed of Halley's Comet, whiyi5p g jwlfn6yy 9lmw/+1svl dr)/h+(le traveling in its elliptical orbit around the iv+/lhn91/y lysd56 y+ l(rm)fgw pw jSun,

  Let the average orbital radius of a planet,n* m;hg pa vkbl7l7yb8y*os5 be R. Let the orbital period be T. What quantity is cons,y58 layv;*pokhmg nbs* 7l b7tant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxc8+i0xwc ce6+k8 xt+g;gjh xj yi8 l1by Andromeda, with the same orbital diec k0j8x+jc1gil; +x8+w yigt68cbhx ameter 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 asyt 9c30k0oj slapg q() one "astronomical unit" ct0 y)0pkqsg(9ol 3 ja(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.f+ef*pf k)hb*

  List the four fundamk7-2co aw .zw/-uuolf) tem9 sental forces in nature.

  An object moves with a consb.).hn 2rhqpz 0de )xhtant speed of 30 m/s on a circular track of radius 150 m. What is the ad2h .0z q)e .bnhhp)xrcceleration of the object?

  The maximum speed around a level curve is 3klpp8gz:c/ s c*a8gi6 0.0 km/h. What is the maximum speed around a curve with twicp8ckz 8 l:6gp/g sci*ae the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle sr6b7afkxcm ut93x1 4wheel of diameter 70 cm when fx41m9sb3tr uk76 acx the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.0d bo*ad rh)wfhp 248dob :6w,z0 rev/s is located 0.200 m from the axis. What is the centripetal accero4:d68a )pbdd *zfwh hbw2, oleration?

  How many revolutions per minute must a cir )d3c8ox qr2xtcular, rotating space station of radius 1000 m rotate to produce an artific8c q23xrxdo t)ial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.n8w w k ,tjuva9(09vin7 m radius turn at 96.5 km/h. What is the centri(n ajtv89w v0 n9iw,kupetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is wht7;:; +gt vthisyd7w mirled in a horizontal circular path. If the maximum tension that the string can withstand is 35ydtsthmw; vg: 7it7; +0 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached tp/awn lnf -h;m-bjm 1e6 ay*;ho a strong string and whirled in a vertical circle of radius r. At the exact top of the pathnp;hj6* wa1 yfa--b/ n;h melm 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 str/+ / ry ub*i.hzte/xyring and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the stre h/ r/r+x/*ztb.yui ying is 3 times the stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experienckwqm 4vxix+ 6p,e ;gq2es an acceleration of 4g when pulling out of the 4mp+xi6,gvqe2;xw k q dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loo nu09e)k-5s :iorq ojsp 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 nonr 5skq9 soij-:0)ou ermal weight. How fast is he going?

  The maximum force a pilot can stand is about seven tila.t4 0tj 4 cirh).-u8dfcnl omes his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of l-.t dh4if4 o0ru c).t ncal8j250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horut xj:ht (m;z)izontal 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(tjm):h;t z xu and each road surface.)

  A car is negotiating a flat curve of radiu 0f* xh:arsebq+xs1jk (rgf11s 50 m with a speed of 20 m/s. The centripetal fofj1r +r h(xfbe0s 1a*s1qx:g krce 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 speed of5;/ctv0 -po) e noewr zr5ij(b 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car to make the turn /b(ere5;r5itvpw-on z o0)cj?

  A car is moving with a constant speed v around a level curve. The coeffici. w9ycj* st5xpent of friction between the tires and the road is 0.40. What is the minimum radius of the curve if th jy*p t59sc.wxe car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a gwgviipox 1w2.6 (1z :ul+inq; jhek:100-m radius turn at 3vg:6n eiwzuwkl2;.j+gxh:o (ii1 q1p 5 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run iv.-. d8o*jff ;x0 pgkqgv2dx vs 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, ba xj5l9 m x,2v7ihssj5unked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 mf.0hi. wy0iw d2m2) pzfsu+ wh 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 end : aypqp7+oux jsp)-q- of a string is revolving uniformly in a horizontal circle of radio-u:sq7+a ) ppj qyp-xus 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 unifvbfg: ampa4j)f1*hh(zd 7s ( eorm rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value in the blm7av*pahf ejh(: ( 4)zsf1bgdanks)
(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 consm qy1zrwl 2 ozx0):f-sists 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 7i,en4p i:6 upw0-kg person standing on the Earth, due to the Moon? The mass of the Moon isi nw6e4: pu,pi $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. Ifsm hdq)2x.ges0x(-rp the masses are moved to half of their initial distance, what is the gravitatp0ssx.x) r e2hm- g(qdional attractive force?

  For a spacecraft going from the Earth phek*na(y1ni5jd( hh 9dfgod8 3 (hqq,:y kc)toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cah,j(hqp o 8h5nd k(ny kdeh3dgi9:)(c1 q*yafncel?
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 ;.pc +648 rkm8edgjwj3 te okkis $7.4 \times 10^{22} \; kg$ 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 q u1q;f)t9ohk7so u2kgj- ) mra distance above the Earth equal to the radiu)u)1s7-f;k9ohquqtk m o2gj r s of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what dis 46tnxag/yjw)y f3( mju(k 0jdtance above the Earth's surface will the acceldt xjj3j)ynwf /auk6ymg(40( eration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dist cjs -.dsr fto(2(;k/yy. lmg4: hvvgoance above its surface equal to 3 times the radisg.gck(y j(;2-o .vfsrmthd: / y4ovlus of Mars. The acceleration 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 peyr-xq ;jr 0p,lanet's center, the acceleration of gravity isp 0jxr q;-,eyr $32 \; m/s^2$. 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(ol lun9)rwg,s . mc qj26ck3qs r. If the object is raised to a height of 3r above thm j ku96qg cl (3qnrl.w2os),ce Earth's surface, what is its weight?

  By how many newtons does the weight of a .x sv,w 52;sop d5lukg100-kg person change when he goes from sea level to an altitude of ov5w2s ,x u;g5.lkdsp5000 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 ar nqpk2d +ei9:s2ch8/ifcei 2 t a point 3r above the Eadisr c2fe: ihe28 2 +9/ikpncqrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four ky ,)e/:vp62kx v)gz7jwskprtg 4 +uf times the Earth's mass and twice its radi feg2k+tvk6yrw7: k)pv)gs ju/pzx ,4 us. If a jar of peanut butter weighs 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 the same line,x/ r7t;fs 8xbu with the Earth between the Moon and the Sun. The Moon has a mas7t8xu/;r sxbf s 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 isff fqg v2(q6)u,ka /jl transported 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 oe0h 7 g;byqbw8.*kqza crx6)drbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radikdbhyr8;caq6z)x .0 *7 bgqewus of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e.,px3k4/3am4z y2xn e;phq e el6 it just skims the surface of the Earth). How long does it take to make one revolution aroun/zle4 6hppem3 qx3e4k 2nxy;ad the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abo ta fci;movq:;-(hf6+ yvny .lve the surface of the Earth. It is observed to have a period of 89 min. What is the mq lf yvc na+:.vh(m6;ti-;fyo ass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital dia nry ht-;d7eu-/5 cpn0vsmh2d meter 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 hysl h5aea( )*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 cr twqt95; 7)ix5yko uzircular 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 5); oxq9 itk zy5w7rtudoes it take moon B to complete an orbit?

  The planet Jupiter ismjo/3 i-y7n eu)4umosc+8yh i $7.78 \times 10^{11} \; m$ 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 orbss7x:r c:sv4aex 3x7 hit the Sun once. What is the average distance from Jupiter to ths 3 sxr:exa :7sv7h4cxe Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)