Is it possible for an object moving with a const/ uzn kb /*yp -+5c8 tayr-skjo1sylq4ant speed to accelerate? Explain/n + ys-oy8 /4k-bu1ptk5j qlr*asyzc.

  Consider a particle moving with con jl*ia +kqs9xl: jv3l;stant speed such that its acceleration of constant magnitude is always perpendicular to i 93;*livq:lxjkj+ sal ts velocity.

  An object moves in a zxysz:/eq l+x00 cop ;circular path at a constant speed. Compare the direction of the object's velocity and acceleras ey:l +xp0 ;0zo/zqxction vectors.

  When an object experiences uniform circular motion, the direction of the acce l,z,jc,,ad,fbg 6op(zjr n+yleratio rz ,d bjl6gnjz,c,, fp(a,oy+n is

  Consider a particle m (rv4x-+v-j6v fkqw5br lidy*oving with constant speed such that its acceleration of constant magnitude is always perpendicular to its velokv*r4bj- f w(qy+vxv6-5 dirl city.

  What type of acceleration does an object moving wi+/sc-,jn ceb/tw dec9th constant speed in a circular path expere+ d//ec-c,jtn9 w sbcience?

  What force is needed to make an object move in a circleggju-r 3y ;d,+oyxs4ion xfyf23u;21. bp eqa?

  When an object experiences uniform circular q0szor;y (nxgy/w2o8 motion, the direction of the net forces(q0yg;2w /xno8 zory is

  A roller coaster car is on a track that forms a circular loop in the-8sql0 p f(ls+dy9 enr 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 centripetal acceleration at this p(d 8y -slepsnfl9qr +0oint?

  A roller coaster car (mass = M) is on a tracu +zm1c v1ekd4k that forms a circular loop (radius = r)v1m+ dzk41ecu 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 follow:osw9 3 mm+zg ks*j:qo5m7:s/c.r 6qot pfntbs a semi-circular arc until it is going straight up. Just as the plane is at itsontgwr6qo:m: qm 7:.scf s9j pzk*5+3toms/b 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 radiusz /pdegkayfqzto(,cm -w* +enxs34:ub 4.t0i $r$ 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 cz43r,gyf wqr .onstant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as i 43. rrw,fqygzt 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 2-spjx9w*mde 6(bmh v speed v. Then it goes around a -s jh*p(mx bmw2v9d6e curve of radius 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 bank sk7 oou .9t51jpt x0tpvgd,w3ed 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 t.w 0k7v5, 1 9tu 3dgxojpsoptnormal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angleo3q+j+c*, azf zpil-v, 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 speed on the larger ra+,qaco+zz j liv3-fp *dius curve?

  The banking angle in a turn on tnmirzz;qku:s 4yoj 1f*e9p (-he Olympic bobsled track is not constant, but increases upward from the horizontal. Coming arounn1ie9 fzjr:m4sqo k*-( ;pyuzd a turn, the 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 object moving around a circular path to have both .-v q)co y-g)ykqref/centripetal and tange r-gcq- )qk.)voye y/fntial acceleration?

  The gravitational force between two objects i 2y,uaq 0 ui,t21ddq:m 6hedgcs proportional to

  The gravitational force between two objects is inversely propi k wmi6krbg9*k4o q -ylxjc; 2pt2g32ortional to

  Two objects attract each other gravitat+,aabl6 /lmu4,rs q ccionally. If the distance between their centers imbaslu,6qar /c+4l ,cs cut in half, the gravitational force

  Two objects, with masses l6k0d 7r0 8 au.y rvg+3kbbdpd$m_{1}$ 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 mazj9 ./pkgu2 ktqrwrzb (j,;h(sses $m_{1}$ 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 gravitat la.a8s z-b x3vch*xm*ion.

  Compared to its mass on the Earth, the mass of an obj3r alb9nl9xsby6 e-oi+uf,m8k1e a:;i4 obi yect on the Moon is

  The acceleration of gr*rof4qnt w4 jm21ve3iavity on the Moon is one-sixth what it is on Earth. An object offtoew* 3imnj2v14q 4r mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, tt af b2p-9rxcxq1.vp4)g9 ww bhe rocket's weight

  A spaceship is traveling to the Moon. At jde.d /q2kro2 what point is it beyond the pull of Earth's gravity?djk o/2e2 d.rq

  Suppose a satellite were orbiting the Ea ew;vh(m9q) l.r)ibtarth just above the surface. What is its centripetaiwmre)a9bq;vt)(l. h l acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of twic cnprelfv0 ;5a7 0/hrlmyd.mj9 pt 5b,e that of the Earth. What is the acceleration due to gv ;m /m rjp,e dt950f5cyp b.7hl0nralravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on2eo9-xtlt g,z/yzq01+yru fj the Moon is one-sixth what it is on Earth. The radius of the Moon i+xtfj/rul 12oqyez9y g -,0z ts one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, budzvx yy31 s 4y 58v0zam/u;ljut planet B has twice the radius of planet A. If planet A has mas y;zvy vldu 4xyz3m158s/j0aus m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twiu,p6s0gmv2wpx ,pul 8ce the mass of planet A. If planet A has radius r, what is theu,pv gwupx826 0l p,ms radius of planet B?

  Consider a small satzz(e7b zy1rt (*jx: wdellite moving in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellitez b: rtxj(71zw(ezd*y's orbital velocity?

  Satellite A has twice the mass of satellite B, and 2haxer -hn(rpc /s*q/rotates in the same orbit. Compare the two hc2aq-xn*p / srre/(h satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward3w7dh(o7a ky* ;jk.u9 mwkhzh8xs0u l . Compare the readia 8z; h lu xyh9kuwm khs3k07wj7*.do(ng on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical pathsh 4x6 7 asqnpk,jnh9cgfl j,(6 arhqk79nj cxjsh6(6n afg,p,4lound the Sun?

  The speed of Halley's Comet, while travelingq (,bqcmd5*r3mch k 0 ui)(p9s 2osbfv in its elliptical orbit around the Su3ph 5fmk imcb srq(,o(qcd9s2)v0*bu n,

  Let the average orbital radius of a planet be R. Let the orbital period bef.z giau0pv(;i b/(w: um ax/a*-xvk y T. What quantity igi.( iau akp-*bvz/ax; m:/uv(0yw fxs constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, w m (5j4lf 5hwlu -rlb0*mxd9suith the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of our Sjllrmm u4sh55( 0ldwf*ub x- 9un, 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 as one "astronozrxt-;tu(,6agzsr;gzb k 6 2mmical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from u6;zbx(ra ,k-tz;r gm2zg s 6tthe Sun?

State Kepler's laws.srbkt:l - x0nb7 l9,th

  List the four fundamental for)nxyk3un d(xu u y4n(8ces in nature.

  An object moves with /sutdae +: -njyvy-7, p/ixk ya constant speed of 30 m/s on a circular track of radius 150 m. What is the acceleration of thy,/ +/a7d yet-nyjsk-:ip xvu e object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum swq) 0v6skc i8bpeed around a curve with twice the radius? (Assume all other fakqcw s)b0vi68ctors remain unchanged.)

  What is the centripetal acceleration of a point on themnd,8l(*ke 4y+ rvv10. rfh wtzyn0xg perimeter of a bicycle wheel of diameter 70 cm when ,vnyz 4d0y0kr(glr8t+ wfvx1.hm n*e the bike is moving 8.0 m/s?

  A point on a wheel rotating au-kzu: y mrl ljd4 33,p.yy8g 0shjkg3t 5.00 rev/s is located 0.200 m from the axis. What -jzl8 ymyud,33g4kk3gulj hr0psy:.is the centripetal acceleration?

  How many revolutions perps/ ria +u4xpp *a5upam1rm6jk z66g0 minute must a circular, rotating space station of radius 1000 p+j1u06r*auaga4ikpp pz 56/msrm 6x m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radiusro k(6y2xitsqrbes:+*v3 x xy- lo-y7v9x : uz turn at 96.5 km/h. What is the centripetal force u-*6iyx7oyxvkrrs t+-o 9( e:x: 3x2vyzl sqbon the motorcycle?

  A 0.50-kg mass is attached to the en nsq;qu,z5nou 3a1 5dz fjqd(+d of a 1.0-m string. The system is whirled in a horiqz d,fudsjn+ aq5n(u1qz 5o;3zontal circular path. If the maximum 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 stv qwf1:hpgft.o la *nx r+9l)9rong string and whirled in a vertical circle of radius r. At the exal ) 9hf.fqtx1wp:or a*ln9gv+ct 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 attach- wm:zy gkx-m bj3)3uc7av 9haed to a strong string and whirled 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 this point is given bymkm:h3wv j3u 9cx7)gy- b za-a

  A jet plane flying 600 m/s experiences an acceleration of 4g when pullinuslkdk(w,j 0 ,g out of the dive. What i( su0k d,lk,jws the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in whixpk df1.hx0*k6ta5i ech the center of the loop is beneath him) of0e1* dkxaf6ip .hktx 5 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 seven times his weight. What is tf. +r5o wx+tgphe minimum radius prt o+wx+.5gfof curvature that a jet 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 curve wit5q0x:6qr ynrch the tires on the verge of slipping. How fast can this car round a second curvqrxr c:qn0y5 6e 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 curs7dgd(sjl / 0bk n:d(qve of radius 50 m with a speed of 20 m/s. The centripetal force provided by frict(d gks ln0s7bj :/qdd(ion 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 spvqyze. q6a:1y eed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the c.q1zyy6e:qav ar to make the turn?

  A car is moving with a constant speed v around a le e/,jc hw yg91.rvnjvi799wc;mvhlc6 vel curve. The coefficient of friction between the tires and the v wr.997cejmvhgj;nw91cy c/6v l,hi 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 na5c;vcz7s9iqd;slv m(o h 6-qegotiate a 100-m radius turn at 35 m/s withou;cvm cqv(5ass hd-lq ;9zi76 ot skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is ar7ic9 8wxw c 8nigo)7banked 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 curveudv e7qye-*0 r of radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked uxdh2em8cu 8nc 0y883p ok2na 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 za:k/qw2q m19vqlrggbmu48wo*t: g/of a string is revolving uniformly in a horizontal circle of radiuz2bv*q4/ gmrwq g:amtu1k wol/: gq89 s 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 car5 k*3gjkcl f(o accelerates at a uniform rate to a speed of 45 m/jl 53 fcgok*(ks 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 consisa-5 uh3k g.gb qn0gf6dts 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 on5wf(ndu fu8q4jog 2 (j the Earth, due to the Moon? The mas2wjuq4ugo(fdf(nj8 5 s 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 attractive force between two masses is F. If the massesj 7bn- v,c :wytk f9a*z9dohg4 are moved to half of their ini:jn zk94a9c ,gy vfobd7-*whttial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from the ei) nl72yi6wsEarth wil e2i iw)nys7l6l 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 iep+n;yij45 2m86 mvvw( xt mqts $7.4 \times 10^{22} \; kg$ 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 distancea)ri)7nnt5 nm above the Earth equal to the radius of the Earth. What is her acceleration due to gra 7irn)t)5mnnavity?

  The radius of the Earth is R.w9q50f80ubdlq o;l fx At what distance above the Earth's surface will the acceleration ofq8q fbx;luo5l d 00fw9 gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 zr )rjzxms l 4:)y2:odq,+ek stimes the radius of Mars. The acceleration of gravity of the satellite, a) r)qjzrysl+d, 4 :z2o:xsmeks compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's+n.ac sc;vy z, h 25/7mrhrjwj center, the acceleration of gravity is;jhsy v+5 m7jrcwr2z n /cah., $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on m bqtafj* bn31wh gx-k1v c9,ruv )9r)the surface of the Earth. The Earth has radius r. If the object is tjnw9m1f9*)v-xb augkr 1) rqb ch,v3 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-kg person changae3,x t:;2nfvpta.gc e when he goes from sea leve x v:ca fatp,.e3;n2tgl 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 mass 100 kg is at a point 3r abovl/mb4gc )x5wg5y (swqe the Earth's surface. What is the satsmy )(gw5w/lbc4g x5q ellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twial3uw; / yg+-ouvwz2lce its radius. Ifouzl3 wl wy ugv+2a;/- 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: jw; lsilx;q uw+(vr3ix)4qk, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The ;xi s;wri v4wkqxlju3):l+q (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 the Mv d3h5s uzhlh + /d7hw(rh8ew.oon.
(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 qjsb; ex3w lc :xn5:6jjust skims the surface of the Earth). What is the speed jxljbe6wcq 5 :s;3n :xof the satellite? (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 the *7 g/boigh,8 9 crhrzzsurface bo/8 r ,ciz9r7hh*zggof 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 2d m+iz-w3c udkm above the surface of the Earth. It is observed to have a period of 89 min. dz32 +miw-cdu What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupitep+o9/pk .:6w;velmdqu d ju8l r, has an orbital 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 radiug t6 z9rs6hb3ks 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 t+4v4pu hu )8rqou06zh0kstq orbits. Moon A has orbital radius r, and moon B has orbital rad8 qkv)str600uh tzupq4o+h4uius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isqx8pg56y d )c6xz5pn n $7.78 \times 10^{11} \; m$ 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 on rk hg3abmh,yp(2 t+p+z6yj4vce. What is the average distance from Jupiter to the Sun? (The distance from the Earth+g ayh+2pm,p r zj vb6hk3t(y4 to the Sun is $1.5 \times 10^{11} \; m$.)