Is it possible for an object movinrd(x a.b5yg(r g with a constant speed to accelerate? Explainby(5dgrrx. (a.

  Consider a particle moving with constant speed such that l x5w,,qbwm:qits acceleration of constant magnitude is always perpendicular to its ,mlbx ww:,qq5 velocity.

  An object moves in a circular pxq5twt; yw. -path at a constant speed. Compare the direction of the object's velocity and acceler;qxwt 5t.wyp -ation vectors.

  When an object experiences uniform circular motion, the direction of ml( eo rijks.5.7ymt7 *mi)mm5y3v tp the accelerar m.m5ki7sl.t*(7p )3e5y ojvmitymm tion is

  Consider a particle moving with constant speed such that its acceled seig-3w c)y2ration of constant magnitude is always perpew 23cds i-e)ygndicular to its velocity.

  What type of acceleration does an ob, cv:k5wm.-urghuav 8 ject moving with constant speed in a circular path experi-:uur.v,hk cag 8 mv5wence?

  What force is needed t dnoisxkx -p8*x *sk9:aub- .eo make an object move in a circle?

  When an object experien6zvi h3u:/b5tr tbwp4e f/dm0ces uniform circular motion, the direction of the net force0u5: emtfbp6/bv3zwd4ih t /r is

  A roller coaster car is on a track that forms a circular loop in th :eyr7 ,0cikqoe vertical plane. If the car is to just maintain contact with track a yiko ec70,qr:t the top of the loop, what is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is 2h z:.n:mxfcgon a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, xz:2ncgmf: h. what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then fol t yxmus*a-jdxc4;5ngg** iy)lows a semi-circular arc until it is going straight up. Just as the plane is at its lowest poyg*ad-5mu4cxij*); ytx *nsgint, 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 *sgr (kp51uvgcurve of radius $r$ 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. 4 xig5:y bzvi j:8zaq;: ctv+d Then it goes around the same curve at half of ybj tx+ : vqgz4;caz5v::i8dithe original 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.x f*mytgrg13xw; -lbhz iub 2s5bq //2 Then it goes around a curve of xfw23u m 5l21ggr/y;bs/ t hi*-xzb qbradius 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 with sp 9q x67zfobdc:/*m g(k:zrxpbeed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal foroc(qbp7d: xmz *b f 9g:z6kr/xce on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the s1dxg(r4d ::n ui: u hin3s(wwbame angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller rind( sxh4:1:(wnug:3wdbriu adius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a uvtr+nsnc 5xx0 k+ds 8(2l64g* zgnhi turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lowergx62nc5g 8rztus*0kn (nh sx4ld++iv coming out of the turn. Why do they do this?

  Is it possible for an object moving arou-(iehhtl/av7 nd a circular path to have both centripetal and tangentialil-at7 h(hve/ acceleration?

  The gravitational force between two objliz0-2qzmb5(.z.agxy l )9pjmh .h9 w mq-bleects is proportional to

  The gravitational force between two objects is inversel74uk9dwce9 ;f(+lb usua 1pouy proportional to

  Two objects attract xham3)sz.w2 m each other gravitationally. If the distance between their centers is cut in z.ah )s3xm2wmhalf, the gravitational force

  Two objects, with masc+*khjs(inma/skubo86 4o (y ses $m_{1}$ 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 masses2gehc./ bkc0j3 :jqj s $m_{1}$ 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 g hdi0.fc48dpasy0vt k +qa69 fravitation.

  Compared to its mass on the Earth, the mass of ana,ug q.rnw7: g object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An o,nn2 q:zq k*t+x/r5w g jh,fxqbject of mass qn/wzhx f 2 gq:kxj+t,rq5n*,
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from hy8odk 5 cg*i /7g4 kfejs: ;1jf3gdsrthe Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond( +/ 4q ; t/uqgfbbbeagis0kv, the pull of Ear (eak s;bf bg vu//tq4i0bgq,+th's gravity?

  Suppose a satellite were oh 2vho/r* 1i53x t-1aofocmpcrbiting the Earth just above the surface. What is its centripetal accelerati-/ra1hoch2mv t1*x fp 3i5oo con?

  A hypothetical planet has a mass of half that of the Earth and a radius of twicenogo,pp y5awti1-c u+31ll di+pmuq2. 1 o4 cf that of the Earth. What is the acceleray1 c- .gai1qw4+n2oo u5 p+ollfp ,3pctumi1dtion 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 is onsu5sl nsf 4f7 ezm-,z6 Earth. The radius of the Moon is one-fourth that of the Earth. What is l4f zeu7fz,n-s s5 ms6the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of jhpis ,/d6 qr)planet A. If planet A has mass m, wqhi/ js )r,6pdhat is the mass of planet B?

  Two planets have the same surfacgoe gp/uv60zjgu8 k0wve:q/ h2i. -wje gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the .ew g6zqjig8vo u:2- 0hkewj/ / 0upvgradius of planet B?

  Consider a small satellite moving iu: y*l o4lva47leauu-n a circular orbit (radius r) about a spherical planet (mass M). Which la e4-vau*louy:u47 lexpression gives this satellite's orbital velocity?

  Satellite A has twice the mass of / k7guxo2pbdl-g55ya*. jsku satellite B, and rotates in the same orbit. Combag kusugj- *7y2o.d5kx /5 lppare the two satellite's speeds.

  A person is standing on a scaly5dl2p z9lc sbp20x)x4xs7zr e in an elevator accelerating downward. Compare the reading on the scale to the person's true weigxbpc zr5 0x y4dl)sx2sp7lz29ht.

  Who was the first person to realize that tb(.b 8 yex j mfdej n85b+u9o76-jdioshe planets move in elliptical paths around th 5-. 9y+eu6n dobmi78f(8bsjbjd joxee Sun?

  The speed of Halley's iv5,ev 85m) butgibz;wf4oj+Comet, while traveling in its elliptical orbit around the Sun,+ ) 5v,iiozme8w fuvj5g4tbb;

  Let the average orbital radius of a planet be R. Let the orbital perioda;rz/b24 d rod be T. What quantity is constant for all planets orbiting the Sun4/drazb;2 dor ?

  A planet is discovered to orbit around a l)wq jql),t m/star in the 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 period of revolution of that new planet be, cm lqt)q)/j wl,ompared to the Earth's orbital period?

  The average distance from the Earth toa(fog-;n g y(e2as) uz+dir7u the Sun is defined as one "astronomical unit" (AU). An asteroid og 7);sidaey(g+rz -( o2uuf narbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.6qfplao 5)u;6fvqse 1

  List the four fundamental forci voo,s5di61xes in nature.

  An object moves with a constant speed of 30 m/s on a citf a j( m8q/a8fe1 j h1+lk,ibj0iwxf j/ea(1vrcular track of radius 150 m. What is the af1wfa,0 /(x11jjk l8bijqiv mf (e/j8haa+ t ecceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the my.nv 1f(tx2tekx9 2wdaximum speed around a curve with twikx.tv (t2wn2 9y1 efxdce the radius? (Assume all other factors remain unchanged.)

  What is the centripetalcb :gift7 pd25 acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.2dt 5 b:pfi7cg0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m frym1dn t2fu/jbg.v6/;3 yd8ew ly iyo,om the axis. What is the centripetal acceleratioy;,v8 6yb2yenlt/udo/3dif . y wmgj1n?

  How many revolutions per minute must a circular, rotating space station of ra 0mk6u4 dg)o p 5.(,xvmrmljjcdius 1000 m rotatj0k4mv(d6)jg m5 . up,lx comre to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes pyi) szwehc9 d3 7; rym3h/xy(mq 4;yb3saj0paround a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the moto;h7sh ws9qy3bdprzpe3/cix yj0ya 4 ;)m ym3(rcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whos0c6wg+q oi)ub jl4 yn8nku9 p(4/teirled 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 the sooiu9 wyj4p n0sgtnu4 / b+c8(q 6)ekltring is not to break?

  A stone, of mass m, is attached to a strong string an7 2m9z s q(kejda4cxef(e+3h 4cawt6a d whirled in a vertical circle of re(4s czq7(a x+ej4wachkfm2e3a6td9 adius 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 attaur427oymw 6 b1.qdi arched to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tensibqo w md.i4a1r7y 6ur2on 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 experiences an acceleration of 4g when pulling out omwwn s s,s./r l*da;k)f the dive. What is the radius of curvature of the loop in whiksw;,rd/ssw )m n .*alch the plane is flying?

  A pilot makes an outside vertical loop (inv m io, s.h:g65ramdi7 ;t4s4lghqf -w 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 hish.g i4o,v;4 dh:5-rslawqm 7 f timgs6 normal weight. How fast is he going?

  The maximum force a p8-i low ue7xjfwwa 3 tz ndvu302w8)1gilot can stand is about seven times his weight. What is the minimum radius of curvature that a jet p w-z8odiw72axegn0uw )fvtul 3j w8 13lane'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-z3z 4.ds. aki 1olc3kpzf4m7em 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 ssc f.pzkk. zlz3 a1d73oi4m 4eame 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 qx:pp7wod 8 yk2d1ea2speed of 20 m/s. The centripetal force provided byo17p8 wexp:ddq ka 2y2 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/ v9 t4c f2kb p9rfu9x crn4ho-*u7hqd 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 turu-hd2r9xf /r cbh*f7cp9 k4vqt 94noun?

  A car is moving with a constant speed v around a level curvejvcza-t(o uu9*p+o 0w. 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 stuo9t+vwpzo0aju * c-(ay on the road?

  What minimum banking angle is xfkp4mu7:29fks e1x+cvp(gw pd h44 a required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictff7 4 +2vsxmpp4: 1xw kke9dgcp(ha 4uion.)

  A horizontal curve osqg qqexte*50uy* 8u.m ;5cv on a 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, p0 0jfmm24yzebanked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked atzmzw :lcgo1r1/l9un+m pq eo.-4d0 re $45^{\circ}$. 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 uniformly in a horizontal ci nrproiemakt:x*+ 1 l n(g6i6x ).8rvmrcle r66rmto.pnv(rkiimex+a8 1ng:lx*) 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, ax pn 3z)jgmoq 28z0mt4 race car accelerates at a uniform rate to a s2oz83q gmx zmt04 p)jnpeed of 45 m/s in 15 s, moving on a circular 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 consk-h+c cd2 7lkfists 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, duvdaai c,q3nw) 17 yr9ce to the Moon? The mass of the Moon c)id y9vn 13r,qwaca 7is $7.36 \times 10^{22} \; kg$ 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 lt70gxh 9.aq-x0 kntb uty23vare moved to half of their initial distance, what is the gragq.xvytax -n9k tb0t 3l0uh7 2vitational attractive force?

  For a spacecraft going from the Earth toward tue fszbjjl l)f 461g-j8w/q1ihe Sun, at what distance from the Earth will the gravitatig1juj8ill/- wzf4qe )1s j 6bfonal 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 z, ypx/y;j0q1n8oq cnz-pi+ xis $7.4 \times 10^{22} \; kg$ 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 above the Earth equal tonej u gu y/cpt13n )d3 3:sxmaxxg,l:9 s,)lgy1 3e tuuxp/xn x c:9an mdg3:3jthe radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's su,edas. sx5kkg7cy;3(xc h go1rface will the acceleration of gravity bkgxyd .h7cosak(g e15, x;sc3e $4.9 \; m/s^2$?

  A satellite encircles Mars a a 5y1jl (fnbb0prpz31t a distance above its surface equal to 3 times the radius o051pnb1 zpyf r3(abj lf 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 planet'c6uhx m,msspn :5 f/+xs center, the acceleration of gravity ,uc5 : mxxf+mh6ns s/pis $32 \; m/s^2$. 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 Ejo3pi8p5a0q farth. The Earth has radius r. If the object is raised to a height of 3r above thp8ifq 3ap0o5j e Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg x p 2a+z+3tpswperson change when he goes from sea +2pptsw3z a x+level to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of j7) zz6yjjd3pmass 100 kg is at a point 3r above the Earth's surface. What is t7z 3pjy)6d jjzhe satellite's weight?

  A spherically symmetric planet has four times the Ear7h4rd61sm abrncg a 3ku)a 9/cth's mass and twice its radius. If a jar of bna/a3c 4)1k dmgr9h67sracupeanut 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, Earth8khy*t+ jmcik *msw3,, and Sun all lie on the same line, with the Earth between the Moon and j*ks8m+3*,h mykitcw the Sun. 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 transported to tr1p*w0cyz 7umn46org:t) u ,uqn m ;bhhe 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 just s;o r i /(sessh(ba)gxf(x3. ovkims the surface osa(r; /xb o((xgsoh .3fv)eisf 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 circularw4o81 bcfn5)7xcfft r orbit about the Earth (i.e., it just skims the surfacenrcw) o f145 8ffx7btc of the Earth). 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 surface of thew1 m;o 7bps 9sg*r2cv+*pulsv Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radius of the Eartbw *7 v 1o9+p*lmugcrpsvs;s2h is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter 0b/piic i 9g98m96wdz /ysvchof $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter oryr00xns:ik7awg9 4g j2pdg i4bits the planet 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 circular orbits. Moon A has orbital radius rgt*q r6 8xss;1t2 vdh22:x:omsncd(x7wmv cw, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long doe*od6x2dqwmx1(nsgswt2m7c v x2 :sc:h;rtv8 s it take moon B to complete an orbit?

  The planet Jupiter int/.xra +rg6i 0o;orys $7.78 \times 10^{11} \; m$ 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 once. Whatsw/f 9u s,jb i9ttuo+1 is the average distance from Jupiter to the 9o js9ws/ tu+fu1it b,Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)