Is it possible for an object moving wit tlk9g ,-8umcg eev:tyi6n ,l9h a constant speed to accelerate? Explai e-ic ,lgk,8u:ngtl9 ve96yt mn.

  Consider a particle moving with constant speed such that its acvim4zx1sr 1h1zey9) ae-hxf5 celeration of constant magnitude is hrex5-9v1 x1yh azsf1e 4i)zm always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. xykw5pf/ *zwt,v;8mhCompare the direction of the object's velocifypk8mwht 5z; /v, *wxty and acceleration vectors.

  When an object experijbu,k5 fz 3q)hences uniform circular motion, the direction of the acceler3fu5qh), zkbj ation is

  Consider a particle moving with constant speed such that its accelk;3rvmj iqk w- 1x;8aoglx6l( eration of constant magnitude is always perpendicular to its velocj8-xl(oakqg1xl3v ; m 6ikrw;ity.

  What type of acceleration does 2 wjsvw y6*jdfkgm8eb09y9q6 an object moving with constant speed in a circular path exyf* sdbj98v mkw6 j260 qey9wgperience?

  What force is needed to make and5yd y76xred,nma.y - object move in a circle?

  When an object experiences uniform circular motion, the fa5(yt wp; sxid +z;7v2pr 4oedirection of the net force isoix(4 y+7ze2 d;5rpa;wpv t fs

  A roller coaster car is on a track that,3e / e(k9lfwd 6snssdd47rbw forms a circular loop in the vertical plane. If the car is to just ddbde l36krf/ws e9 ws(4,n7smaintain contact 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 forms a circular loop (i) bopi)30k 3 l+xynkwradius = r) in the vertical plane. If the car is to just maintain contact with the tlyn kixbipw3)+ k 3o0)rack 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 4ks* q xxnar0: n,l1jrsemi-circular arc until it is going straight up. Just as the plane is at its lowest point, the force on him 4rnxnk jq1:,slr 0x*a 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 om nryfp8( (c)nf radius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a cu+bo jn9b l5+lurve 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 f+bu jbn9ol 5l+orce 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.r:pywia 4cc65p,1x tj Then it goes around a curve of radius 2r at speed 2v. What is the centrip1 5wxi,:ayjtrp64c pcetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked;d psr a0u(hy+ g f8hqxs4u/9v curve of radius r with speed v. If the road is frictionless 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 equal0; a4puvgsqdys+hrfu/h 89x( in magnitude to

  Two horizontal curves on a bobsz s 7n8w3t67xrk f4woeled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to6w 7 47f3z8n erxswkto 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 bobs* op+25av mgcnled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of the turn. Wha o+*2np5vm gcy do they do this?

  Is it possible for an object movingmkw59rfv::qvxmekkb k.q 6 ar,n-k -+ around a circular path to have both centripetal -b m arxfrkkvqkn,+w.k5: -: ve6q 9mkand tangential acceleration?

  The gravitational force between two objects+ykh4xr8 6.;pdvi4mh oiw m-s is proportional to

  The gravitational force between two objects is inversely proportionq +u:akv8+fso8 gx/o uxn 5-lsal to

  Two objects attract each other gravitationally. If the d9b1h1 oc(lf dsistance between their centers is cut in half, the gravid(fb 1ls 9c1hotational force

  Two objects, with ma4 ivs5v35wnobzttbg/; x:ht -sses $m_{1}$ 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 masse*5qb veac3 q4dh7q4a*z; *bi myqik5ms $m_{1}$ 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 gravitationbgtvjusl1kv f 4+mb65dbdby *n5+ut*.u q; ,s.

  Compared to its mass on the Earth, the massa fx0rl4 4b:xs of an object on the Moon is

  The acceleration of gravity on the Moon i0y*i i fypqac7:ln s; qt01 d31xcck*cs one-sixth what it is on Earth. An object cc:*c1 cqilk* q;0t dnsfix0yy3 ap7 1of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocke2-5c2mu lx)z.n njn set's weight

  A spaceship is traveling to the Moou,cn, kj3. y y2tp2woyn. At what point is it beyond the pull of Earth's yj.,pcny23u ,2t ok ywgravity?

  Suppose a satellite were orbiting the E x-p, 4n5a jpm;l*r uazvh.0wparth just above the surface. What is its centriuzh pnj m4a*lrpv0a.;5,w x-ppetal acceleration?

  A hypothetical planet has a mass of half that of the Earth and a rad(f6cc6tzam1(t n7oz wius of twice that of the Earth. What is the acceleration due to gravity o 6t6 mza(1 o(czf7nwtcn the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravifaffh z ( 93or6c0f*nsgx, hd-ty on the Moon is one-sixth what it is on Earth. The radius of o3fc9rs n(x hfg ,a6d*h-zf0fthe Moon is one-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 twicceo+ aaa n,feg430r4 be the radius of planet A. If planet A has mass m, what is the mass of plane4f+eba43, oan0rga cet B?

  Two planets have the same surface gravity, but planet B has twice the mafk/ cr 06d)lzz4by7 woss of planet A. If planet A has radius r, what is the radilk d)/0c7w r zzbof4y6us of planet B?

  Consider a small satellite moving rc/,g).lu)am d o 4 wfq4(8obtqem ez8in a circular orbit (radius r) about a spherical planet (mass M). Which expressionm ou4 (fwect,.)4zladoeq 8gq)b /r8m gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, num9 94w i)p0kdyjx 4uand rotates in the same orbit. Compare td9 mwy)kpjnuu44x09 ihe two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Cbk2(c trz3 n,jn+moo kz-+ zl8 4vdrv0ompare the reading on the scale -brocz v4lk0k8n r( d+ojzn 32,tz+mvto the person's true weight.

  Who was the first person to realize that the pl25 xnyv76uq)k tsgy86 db)mww anets move in elliptical paths around the S kd)tbs66mx)5w n8uy2gy 7qw vun?

  The speed of Halley's Comet4yadf3 )o ymu 2 tqu4omj f9bo-),cph2, while traveling in its elliptical orbit around the offy9o t),uqm4u)aoj bc3 - dm22hyp4Sun,

  Let the average orbital radius of a planet be R. Let the.agz 56 ig8oha orbital period be T. What.aaz5o8h 6gi g quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit arn 9hkt),,ib l2fpxd5hnx+g i2 ound a 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 revolutioxki,f ,59+2xbltpdn) ghn2 hi n 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 "astrgduv1;, y t ie+..r( gx,uc c-(lrk9xn6xi iguonomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroi i; l-n(rxy.ug,d ui(+9uc1 xeg g k.,x6ictvrd's average distance from the Sun?

State Kepler's laws./xb778e abrf. j/ saze

  List the four fundamental ford ptq q)2g0d ee(-)gfsces in nature.

  An object moves with a constant speed of 30 m/s on a o lq0da sfuv+(w 2dd*oj;es,f.k+9zp circular track of radius 150 m. What is fa s0oj+ez d ok(*9dps+w 2fq.,dulv;the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the max/k y tyztp24b:imum speed around a curve with twice the raz:tkbyy/4 tp2 dius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a poinpkgs d79)-y;ay jyy6it on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s?kypy); i9g- sa yyd7j6

  A point on a wheel rotating at 5.00 rev/s is lo ua,+i:wxyok j (,1yk 4nm+cc )0vym11lvsgo ucated 0.200 m from the axis. What is the centripetal acceleraty, wy)ma1i1+4kj0 o( y xmu+ngv1ckv osu:cl, ion?

  How many revolutions per minute must h*b 8 .iviylb+a circular, rotating space station of radius 100.lbi h b*ivy+80 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass oful 6.mcx fzs 1:-fxro mv:x7.f 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is th ml7 f:u:-x f xfm.oc.szr61vxe centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m stringa z4djc 6:dstc nmdr,()fdc- 6. The system is whirled in a horizontal circular path. If the maximum te n dz,s-4cd)(:j rac6mtc6dfdnsion 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 an1gx. *h58ixjopis:hyn xbl( 4d whirled in a vertical circle of radius r. At the exact top of the path t:xo hy8i* p4ns5xh1bi gx(. jlhe 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 whirled igm* wwdf 3hemr+f,6 h:n a vertical circle of radius r. At the exact 3*emw d,f+6hm:fh rg wbottom 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 experi;uh f3bz6(h:fct (rnw08ht qp ences an acceleration of 4g when pulling out of the dive. What is the radius o n w0thp6q8u rf(h;z3(b:ht cff curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical ;yvae1m d i 3xam68gn,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 goin;y36, avgamx1edm i8 ng?

  The maximum force a pilot can stand is about seven times his weight. What is thx1t83 *xh z *k*/lyhv ra l3m0p)zam,nhin n(fe minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250 m/s*vl,iz3/ (aynfhxnz3hrl a mx)phn1*mk8*0t?

  A car traveling 20 m/s n g7w)p tx 4n01/rzx+wolqw d9rounds an 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car rouz o)w 7d+xl4/xw ng 0rtqwn19pnd 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 a flat curve of radozc)l hbszmp8l1l178q+;sn 9v +3xx6tlg opnius 50 m with a speed of 20 m/s. The centripetal force prohpl 17o 6z mb38l+xsqlzcno8g1;lnpv9 txs+)vided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curvezl; 8f(ud/h tj 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 z/ dltuh; (8fjfor the car to make the turn?

  A car is moving with a constant speed lckv3+*9wf /v sxuoh/ v around a level curve. The coefficient of friction between the tires and the road is 0.40. Whah 3vxfsv/kow+lc u /*9t 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 thwpq6xh inl-u6(;ks;* n7 jjk o negotiate a 100-m radius turn at 35 m/s;x;( ijhh p-q*s6 k6 lwn7knuj without skidding? (Ignore friction.)

  A horizontal curve on a bobsled ruaofzln07dst6:*g+y6 zwny 6en 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, ba 4 q-usccmh1kfzy.z i98+d;aenked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banaq-lm v)sdf/+).ru f fked 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 of a string is revolvi vx(+8,x-oarqd8n)h l 4h yvqnng uniformly in a horizontal circle of radius n8v4onqqv,d(hy hrx8al+ x -)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 hvt8b);qcx7vg p0ar-* j5:f o4xfqw wa uniform rate to a speed of 45 m/s in 15 s, moving on a circula - ar :p0b5*t vx 8)ffowqjgwv4qc;h7xr 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 consists of a proton of ma kh )h8zu +fsu/b(1i(oo l*htsss $1.67 \times 10^{-27} \; kg$ 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 ogm40 xnf;q7v jaaz apvor28.i(p h9)70-kg person standing on the Earth, due to ta4n)g a;2 fivom 8opxj.pahz(97r v q0he Moon? 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 attc+i9 t;,vqc-hys;kn/l9 xgpkractive force between two masses is F. If the masses are moved to half oqht- +svxy;k9k 9;,cp i/gcln f their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward :l6z(w ,kisgjs j7y-hgu2r q3 the Sun, at what distance from the q6hjz2(sg3g r slkwu:j-iy,7 Earth will the gravitational 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 is pi5+u ha +0o+d:xpcon$7.4 \times 10^{22} \; kg$ 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 distancewt r-8f5g lxv1 mb,rmxb-2rn0 above the Earth equal to the radius of the Earth. What is l x-vf 1mxw-rb,50tgrm r 82nbher acceleration due to gravity?

  The radius of the Eartq+ b 00m(z cyi ywa3wh2uny2.ih is R. At what distance above the Earth's surface will the acc0z yayy.3ic u h0w+qnb22i(wmeleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a dis5n39 i+jxkxjxnx 8* mutance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surfacem9+i xxu5nj8k* 3xxn j of Mars, is

  At a distance of 14000 km from some planet's center, the acce4 z2fpqmg +5 dcyacu(w7a8dxnop6h (+leration of gravity is z6pcmq +pwd u 7 +c5ahx fdo4g(y8na(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 1sd t;6l37juuy g,qatN on the surface of the Earth. The Earth has radius r. If the object is rag; studlau31 yj tq7,6ised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person c/r8ml y(8kpj 3ys 1nyydv1je 5hange when he goes from sea level to an altitude op5my18y3rvy(yld/s 1e nj8kjf 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of ma;w t.ojot6w hq 5uj4a:ss 100 kg is at a point 3r above the Earth's surface. What is the satellitej4 .;qa5o twwt ju6oh:'s weight?

  A spherically symmetric planet has four times the Earth's mass and twice its w,wh gd+gduv;2b.c5ox6ef f7radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would .b,x7dw5;+2 fvfgowdghcu 6e it weigh on the surface of this planet?

  During a lunar eclipse, o8( bpji2pr .u;ale5an: to6 nthe Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Suna(6 rn2put;8io5:lbn pae . jo. 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 thes1n2y z)o 8(buo5vafxz,a ,ac 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., y* q1of xr-r*oit just skims the surface of the Earth). What is the speed of the satellite? (The mean radius*f r-o*1 yoqrx of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the E)n: 6jjeet2 dj .qe(jn33j zkcsxl3l7arth (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 (l cjjkz ednsne.q3x:elj233j)tj76 the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abov l 9;4mvxn0.yjuzfo6/lhj s6se the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (Theo sj;s 9fyhz.4uj0v/ m6n6lxl mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameto s hhx+dxng +9+d0nx)er 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.di: vx el.ir op7ia42 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 zeu1./ yh xln0d9ds rth )):zinearly 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 moon B to complete an orbitsx i d19z/ey:lzur0)nhd) t.h?

  The planet Jupiter is 3tfwqb)uxjsp ai*i1mim 82 7u9 ;kud1$7.78 \times 10^{11} \; m$ 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 yearsj*tf(m7 q.4 3k-jowvm vfs/ kp to orbit the Sun once. What is the average distance from Jupiter37/.mo w ffv -tq4skkvpjj( m* to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)