Is it possible for an object moving with a constant speed to accelerate? Expl xa 0*mw7spz(qai7(0x zq* aswpmn.

  Consider a particle moving with constant speed sucu3uq6 9k z; 12e w:uwlrgulne4h that its acceleration of constant magnitude is always perpendicular to iew;l413q krw9 zne ulu2:uug6ts velocity.

  An object moves in a circular path at a co kg0arghes,j* ii)6jvm ).+ksnstant speed. Compare the direction of the object's ve,*s)g0m+jj6khk). s v iaire glocity and acceleration vectors.

  When an object experiences uniform circu;j 0kt jxcmx06lar motion, the direction of the acceleration t60x0 xk;c mjjis

  Consider a particle moving with constant speem o)-rrxwn9t2 d such that its acceleration of constant magnitude is alnr 9-t2xm )worways perpendicular to its velocity.

  What type of acceleration does an obj4bi)- lexf wm68,sx mnect moving with constant speed in a circular plie8xnm-4wxb,s 6mf ) ath experience?

  What force is needed to make an *8 l-9lk tucns4gm.15epmmmyr7l qq 4object move in a circle?

  When an object exper;it6 irjq0i bx;oq: 69c .6x7dqosv rciences uniform circular motion, the direction of the net force cio6j:0.tq b7qs9o 6ci xvd6rq i;xr;is

  A roller coaster car is on a track that fo m4v4kusa(tw0ga wnx ca37;i/rms a circular loop in the vertical plane. If the car is to just maintai 4vc ua ;sk3nxtw07w( ami/4agn 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 (radw7 .g w/auwwy/ius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the lo./w wwya7w/ug op, 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 pn5fw:j fi 3,j1-ndu vgoing straight up. Just as tdj f3w :pf-jiu n,n51vhe plane 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 ra*emx8ct f(ql8hs ):g* z+eurc dius $r$ 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. w ryb sq9p3t:5Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around ths 5:bt93pq rwye curve for the second time, compared to the first time?

  A car goes around a curve of rll7 *eda,*mze adius r at a constant speed v. Then it goes around a curve of ral7*e la*, ezmddius 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 bankca/u+ oxk4pn/2e guue5+p u2*xnz yu, ed 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 2e5a+xkp / /n,c+gu*2z yuupn oxu4eu the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on hbc)uoh2 ;-j d8ql w*ka bobsled run are banked at the same angle, but one has twice the radius of the othe l h)wjbd8co;-k*hq2ur. 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 radius curve?

  The banking angle in a turn on the Olympic t+sf )92x/fdsc +pdw e-pjt ,bbobsled track is not constant, but increases upward from the horizontf+pp-sx /)2b j,cdtets9 dw+ fal. Coming around 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 tn)xqf ,z0 d0,moaf-jboth centripe mj,oq0t- afn0z,df)xtal and tangential acceleration?

  The gravitational force between two objects is proc dl 9u9ejmbut j2:;z6portional to

  The gravitational force between two objects i dfy kwrx+* *bb swq3:)kcfd00s inversely proportional to

  Two objects attract each other gravitationally. If the distance between their coxrz vgvu-z5e vi: .688k2wnbenters is cut in halfxz wz6-bikv o2 ev.ru 8vn8:g5, the gravitational force

  Two objects, with masses kg/86+v0e( miplqdvjl8n7 podz8 * dw$m_{1}$ 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 masshqh+,npyj *7qvvk,k cxk;/ -ces $m_{1}$ 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 gra;zm /vby,z (8duryiy8.3 bk/cm b;qo bvitation.

  Compared to its mass on the Earf+stx5-uqlf j 4if6xy(7-jwfcrl) e; th, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. Aufr2qy9qw - ymyx h0t1+)(u9jnu1vepn object ox 1 ut9)pqfmvyeryw(0j2n9+ quh u 1y-f mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the+: f( kj ;elgkan7l*k mr e0tbuq2:9jz rocket's weight

  A spaceship is traveling to jflc ;y( b) 01m e7cwfgdci26nthe Moon. At what point is it beyond the pull of Earth's gravity?ldb f02yi) ne m6fgjcc7c(;1w

  Suppose a satellite were orbiting the Eafqvjkk a: 7ftlz, llvv )8lu)1oes1 5:rth just above the surface. What is its centripetal )e:1sjk8uv: vz1ll lf,5 ) tvfq 7lkaoacceleration?

  A hypothetical planet has a mrvap(j(g* )kr ass of half 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 o)*rgv (ka(rpj f g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it x 6cligf2np 5/2vbi :his on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass com:p2 lih/g5 iv2xcfn6b pared to the Earth's?

  Two planets have the same surface gravity, but ; :p k8n1vrnwpplanet B has twice the radius of planet A. If planet A has mass m, what is t k81nppn rvw:;he mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the massp ou c2- zidgx/v o8)wl2*tz7j 8l6jyi of planet A. If planet A has radius r, whi/jzl-gol 7u 8c )tjy2w zdi6po *8v2xat is the radius of planet B?

  Consider a small satellite moving in a circular orbned6e )(u dx7yit (radius r) about a spherical planet (mass M). Which expression gives this sate (x7eeu ndyd)6llite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rohm43h)ybgtm*2qt 2 j htates in the same orbit. Compare the bh )mj2h gmtt3*qyh42two satellite's speeds.

  A person is standing on a scale in an elevatdox8ts n ad-4lv4h20yor accelerating downward. Compare the reading on the scale to the person's true weio8ah2 xt 4-lsvd4 ny0dght.

  Who was the first person to realize that the planets move *b w9p0:xwcq cm *x+vuin elliptical paths around the Su m0:v*+qxcx* c wupwb9n?

  The speed of Halley's Comet, while traveling in its elliptical orbip/demeraq6 uk,hp96h* ,mb ,ot around the Sunmko6bdhe e 9,,*aqhr/, 6mpup,

  Let the average orbital radius of a planet be R. Let the orbital period be T. ir1f+nhji ;2m What quantity is constant for all planef2inh+ rij 1m;ts orbiting the Sun?

  A planet is discovered to orbit around a star 5 dr+4:cp8nc ctv*)l ttxpt3v in the galaxy Andromeda, with the same orbital diameter as the Earth arctcc )dp8+5x:nv3*4v p tttlround 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 defi(wujuw3cu,8 i5.qr7lg r dv +uned as one "astronomical unit" (AU). An asteroid orbits the Sun in one-t +uu7rq . (wrc5vwlgd8i3u,j uhird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.+qldf(gpz)dc*k 1 m-i

  List the four fundamental forces in natures .ua/vyd3x2 y.

  An object moves with a constant speed of 30 m/sz2salg9a 0k d1 on a circular track of radius 15dg2a zka9s1 l00 m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum sm70f2f gxo+ hqpeed around a curve with twice the radius? (Assume all other factors remain u+ 7hgx fomq0f2nchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicycle )0;wqm woqnx8 wheel of diameter 70 cm when wqm0q8) x on;wthe bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 reqwut/3y+7q mw p3vwp 2v/s is located 0.200 m from the axis. What is the centripetal acc+u7w/y v3 3p2t wqpwmqeleration?

  How many revolutions per minute must av-q- un;r3b7p vdycx+ circular, rotating space station of radius 1000 m rotate to p rvyn37-bdx;uc p qv+-roduce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96orl:l 1 sydsi;p229 ys;trc7 u.5 km/h. What is the centripetal fi;r t1o7;ssly92 y pl2rcsu:dorce on the motorcycle?

  A 0.50-kg mass is attachedz 57own.*y)m,yskiomgcd tc1 y(f* )r to the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum spy,zoy)5 **m1fm(o.krtsd)gw yc7 inceed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and 16skk /x3lux at ,5ykiwhirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stoneax i,5316y sx /ultkkk's speed at this point is given by

  A stone, of mass m, is attached to xrf8nmsl8 v3fbp j)x zo+;i*k 5npj20 d 5er1aa strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the j;8 58 efrn2*x)v3j1dp opsb0f xa5zknmr li+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 experiences an acceleration of 4zlqh ,8xr4x4 ig when pulling out of the dive. What is the radius orqzl8x,i xh 44f curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is benea kkn5v klymqe.d3;j,+th him) of radius 3200 m. At the top3, k;q5yed+j.lvk nmk 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 ipi 940vbz*tv times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, cantp 9viz 0vb4*i tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve with the tiresl7sbk6 1ret:o se 6)ff 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 and each road surface.6ksebsot ) 17 rlfe6:f)

  A car is negotiatingv9gc x6hj a4y je:8;5und8gxg a flat curve of radius 50 m with a speed of 20 m/s. The centripetal fo48:dcgv 5ujhj ;ggnxy8xe9a6 rce 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 fp++mw pxq87rof 14 m/s. What must be the minimum coefficient of friction between the tires and the roa+rf8 wpp xm7q+d for the car to make the turn?

  A car is moving with a constant speed v around a level curve. c.dsegq9 q 2w )n+3ocf The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if2cno3.gqq f ews c)9d+ the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate 7f)m z7x wnqy;a 100-m radius turn at 35 m/s without skidding? (Ignore fm;7nxy fz wq)7riction.)

  A horizontal curve on a bobsled run is banked o( )6t386gfp cltl3bcpxxfo7at 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/ yl2 pel9 h6p;fp/juu 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 ai/iov xn t78+2rovl/5i fo /dat $45^{\circ}$. 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 horizonta4 .lrfui0 1(nhd5ovpxnni; s2l circle of radius drn241;s xf(. o0inpnli5huv 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 acceleratb4g ymi/ewzxg ,u,g69es at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical value6m4 z ,xy9/ ,gbuigweg 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 consis53dwsv ,d/zi v(my, idts 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 0blw5+v)v ogp v*vdr8person standing on the Earth, due to the Moon? The mass of the Moon isw *pv50b )lvvvo+g8rd $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between two masses is F. If the m/ufonn)e wx1ghn6). dasses are moved to half of their initial distance, wha)n/g xwn )u.6nfed o1ht is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distak;n i0qyybfe m)kw3dgh +r9 p-a(9zl.nce from the Earth will the gravitational forces due to the Sun and th(9 a;kqi -w yzky9p)fh.0mndr3 b egl+e 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-1g+m 2ghcv 7jftfx +l,nd ;cn is $7.4 \times 10^{22} \; kg$ 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 abxhod30:svz:n t ;hdw 7f6gi,l w2w 9zyove the Earth equal to the radius of the Earth. What is her acceleration due to gwo9d6gxfz hww;i:s ,n y 30h :2ldvzt7ravity?

  The radius of the Earth is R. At what distance above the Earth's surfacczz2xwlp)j q6buy3 rzp03)u8e will the acceleration opby6 u0uqz)cl23wz 8jxp3 )zrf gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars aqnv)*o+ly4e v()fg7 ;6wa4cpt.(hcq a orsd lt a distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration ofsalpyqv(+l)) n4ot;w odcqe*f c6g 74arh v(. gravity on the surface of Mars, is

  At a distance of 14000 z1g/7ff g u7b u3(cuypkm from some planet's center, the acceleration of gravity is /pufcu7y f 31ug7bz(g$32 \; m/s^2$. 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.h rq nhyg ,+ uqta;6cs4z :l.-*rbhq.f The Earth has radius r. If the object is raised to a height of 3r above tqrr.tlcq qg6: .s,h;zfa4*n-h+ buh yhe Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he goes fro f mxu* :tek 61yi+20ln,1f oujtabh7rm sea level to an altitude of ux0jt hbeff +27la1mi :kuryn1* t6o,5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius 7xmqg8 80nel)* sfve br. A satellite of mass 100 kg is at a point 3r above the Earth's surface. What is theen)m78bg*s xvlq 8f e0 satellite's weight?

  A spherically symmetric planet has j myu 8 y7l(gq,+ays)rfour times the Earth's mass and twice its radius. If a jar of peanut butter (y8yqr7s,)lmg +yu jaweighs 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, Eartd +6y4tftx up4h, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Mou td+4t6 pfy4xon 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 transpoac7(saf 8 w:mlm+zl-krted 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 thqvbjfpq1,0n(z 5uufe yj.(/ oe Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The qq.zufv(j/1j50op,y un (ef bmean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (: fh )//kp zfb1i wdmn8gut1w)i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? gi/)nz / wt18pfb1ku d: mhw)f(The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circum+48y21 mbq 4j0og (smpf)1xtmrst y vlar orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is th+ g1mb 4)tmjmtm4yx 2so0syq8rpf v1(e mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diamet h5ym3knzj42qf;up /jer of $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of J* - x;tr+j/pzur1hbo 8ud mwd9upiter orbits 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 circulq sd1sk2ij4a7ar orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon skaqj 2s4i 7d1A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isz1 thl ns s:)bbs+.z*j $7.78 \times 10^{11} \; m$ 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. Wha34 )ooj :q fc+:;vt fhbj7ieaqt is the average distance from Jupiter to the :ifqhba: ;eoqc )oj4ft3jv +7 Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)