Is it possible for an object movin -u3bd a0acy v2sni+z/g with a constant speed to accelerate? Explain.cda a /- y+z3svni0ub2

  Consider a particle moving with constant speed such that its acceleration of et7d dwny-p9mz ;y 3k(5pw5lg constant magnitude is always perpendicular t3759tgk y ;zpml(ey-pww ddn5 o its velocity.

  An object moves in a circular patpr)duao2+ 51aka ze+jmva27d h at a constant speed. Compare the direction of the object's velocity and acceleration paar1dmjd5u+ 7+k2va2ea) z ovectors.

  When an object experience1zfre 7seasz,up po768 +na +fqty 03fs uniform circular motion, the direction of the acceleration inz +386, youe7spztra1sea fp +ff70qs

  Consider a particle moving with constd/ams3 skuv7qe e2;k9ant speed such that its acceleration of constant magnitud7; eqemuv3s a s/k2d9ke is always perpendicular to its velocity.

  What type of acceleratioc3);:wcmnxu dw uomhd3 , ir+8(0yqpon does an object moving with constant speed in a circular path expch onymw xdmqu0 ;u:cdr ,i)w3(38p o+erience?

  What force is needed to make an objectaw/l46ux,vx dv-8vv eh s,o* b move in a circle?

  When an object experiences uniform circular motion, the direc/qt.wo 6fzla *tion of the net force islf6*waqt o/ .z

  A roller coaster car is on a track re8w xa:3wg)zd+ ssa. that forms a circular loop in the vertical plane. If the car is to just marg8dw. za3:x+ )saewsintain 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 afx jk24of)k5n-tiy(h8scww .w* 4 e ka circular loop (radius = r) in the vertical plane. If the car is to j4t2 was w(i8 kok5wnky.*hf )je4-cfxust 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 follows a semi-circular arc until it is3 .q6x/dj li( y- ,nlyla*a y0uukyo:v going straight up. Just as the plane is at its lowest paoyiv0n,*d .l /-a u:lx3 yjy(6lkuyqoint, 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 .xoq4 +h;rw) cs-os9ung)xssfc q./nof 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 ;ioy+.1klzrz *x32c 3v,kt ii,qbe gh r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curvy k,+i1q t kz,2ir3heo3gbi.x*cl; zve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. Then it goes a me i y(axnkv,tu:uf806g6)hhround a curve of radius 2r at speed 2v. What is the centripetal force on the agkt 6 0uu(x:enf)yh, ivm6h8car 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. o017nro wjr(r If the road is frictionless due to ice, the car can sti 7orj r01(wonrll negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves onh4gc/ ,) vxogx a bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no frictio)x/v ,gx ohgc4n 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 bobsled track is not qy7qhm a5s ayf7faqja x(x3c/. :5y 4yconstant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentqaxa/ 75m3ys.7x(a4q f hfc5 :yaqyj yionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object 3xdoe1-xsn-xqz+ r0 emoving around a circular path to have both centripeta-qs 0zo -dxx1 neex3+rl and tangential acceleration?

  The gravitational force between two objects is proportionn mn -e.im3c2gopyh85al to

  The gravitational force between two objects is inv ui1ufe 0d+4 vhbw vh9bgnedu-fl 3532ersely proportional to

  Two objects attract each other gravitationally. If the distancevdm2k)wom(iz m: 1b5f ,n mdm. between their centers is cut in half, the graviti.m : m)z n(dvom51 b,kmfmwd2ational force

  Two objects, with masseoy8xg8( 5a8 cbvjq1dps $m_{1}$ 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 masso7 bn2dw /oe(nes $m_{1}$ 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 gravitatzrst 2l2 ohc2h0ag wxtzoa /:659j r(jion.

  Compared to its mass on the Earth, the mass-btbp5(+1m ahd 5ec nn of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Eay ni/rm 2gt.9krth. An objeir ./9ynk 2mgtct of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth'sg qy2l5bez oy .e-t0-b surface, the rocket's weight

  A spaceship is traveling;7f f1a;iw 1jzoyrfe) to the Moon. At what point is it beyond the pull of Earth's7; 1ezfra ;yf)o1jifw gravity?

  Suppose a satellite were orbiting the Earth jn-6t i k iej32jel7.hhust above the surface. What is its centripetal acceli-jk7.2 6nihj3 tehel eration?

  A hypothetical planet has a mass1eyu6q 29 qtxs5c,co *,vfyce 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 in9 so u,eey xcy61ccq25*, qvtf terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on3:sra6 sn2y)ev ifjx- the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's m3xf 6 ny:2s)ajer-i vsass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has75p9y(rjioa t9 s 4gas twice the radius of planet A. If planeoyj5t(spr9 9i a74a gst A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of alu8mbc jqrgdc * .nn9ni f5g)u4-hz:-c mt.;plan-da j 5c;mhgb *gu..:unm8nt)9cc zfi-n4rqlet A. If planet A has radius r, what is the radius of planet B?

  Consider a small satelliteyev+k:vi 0.o8z,aaqhy* c81 ueasewh5ge1f( moving in a circular orbit (radius r) about a spherical planet (massi+ gawh 85v 1aq*yv: z8y,e0h sfa.o ce1ee(uk M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite amhw:tppy)l/n/9,f7 li ul5 k B, and rotates in the same orbit. C5lal/ l pphmkftw,7y)/n:u9i ompare the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compae ; ks;rczc l,b-bs9*ny5q-l qre t-zy,5;9 sbqqk-clleb n c s*;rhe reading on the scale to the person's true weight.

  Who was the first person to realize that th7)a-dyyq+ j +qyecxn7e planets move in elliptical paths around th +e7 xq+ycqyya7 j-d)ne Sun?

  The speed of Halley'susrq1t2jja .ji7n/8m Comet, while traveling in its elliptical orbit around the Sun, 7j 1asjjq uri2/n.8tm

  Let the average orbital radius of a planet be 6p0m5 fdjwb d.R. Let the orbital period be T. Wp6f w.0dm 5bjdhat quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the g 1qs zwt 1r 32qvftj*a,sb0bw*alaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass oww13bvatq,1 *fzr0 qs bs tj*2f 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 as one "astronomicawt3 77 ww2atqbl unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from thebw3 27aq w7wtt Sun?

State Kepler's laws.t a4v)kyu(zl1 d7udjh x9n6u;

  List the four fundamental forces inp7.z5qm t j-okd d);ty nature.

  An object moves with a constant speed of 30 m/s on a circular track of jzug st3l64;bradius 150 m. Wjug6;zbslt3 4hat is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the .swecjum;dm x - /05icmaximum speed around a curve with twice the radius? (Assume all other facu;e0cw/jmm dc 5 .xi-stors remain unchanged.)

  What is the centripetal accele0qdmvawnykek2)q 7ai1*g+x7 ration of a point on the perimeter of a bicycle wheei0+x7 d m)y2wgk* eavn7ak1 qql of diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotksw y: 6 5vg)bwm7cz9sating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal 6s)mcg7 wwsk:59 yvbz acceleration?

  How many revolutions per minute must a circular, rotating space station ofa/l d60gyeul* radiu/edg 6a*lu 0lys 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around awq1 8odwgs(,7o/lzkz 13.7 m radius turn at 96.5 km/h. What is the centripet(gos1wod kw8/q l, 7zzal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 88* wggffl6rw 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. What8glfrwg68 *fw is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong ekzmv09i+ :9kp(sd ievrx1n7 string and whirled 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 stone's speed at thisi( re:iz0 +vkdp199m vke nxs7 point is given by

  A stone, of mass m, is attached to a strong string and whirled in 4ohf9,bzda(cc 4eb j5a 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 ston5hbj,9e4cbzacd4 fo( e's speed at this point is given by

  A jet plane flying 600 m/s experiences an acceleration xh7f-dasmzxg r 86+ j8:1pezh of 4g when pulling out of the dive. What is the radius +8-fx z zhjmgph ra16xed8s7 :of curvature of the loop in which the plane is flying?

  A pilot makes an outsj k*rlloh) 0h)ide vertical 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 weloj))h h* 0lrkight. How fast is he going?

  The maximum force a pilo*0zg45 pxmhoii qly +l5w/z )qt can stand is about seven times his weight. What is the minimum radius of curvature that a jh4 p/yq)lz+5ioq 0gwzm*lxi 5et 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 with the tires on(e.hewue(y,yenj 5 yi mdl,r.:a1 q.eyo:d )a the verge of slipping. How fast can this car round a second curve ofr( dniwj .qe,:de1:mla(oy.ua ,yeyy) e e5 .h radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curvehr-6wnlj*v ap v5l rg:wx0.*x of radius 50 m with a speed of 20 m/s. The centripetal force provxrnw*x: vp5wll .0gvja* r-h6ided 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 of 14 m/s. qscb, ,l iq u-++f1zpmd ;8lgxWhat must be the minimum coefficient of friction between th,q;g+x+pcms8f l,1dbliu qz-e tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The coefficien-/16w dgsh xzkc 98fcq4ett 5at of ff q169skt/ga thzx c5c4-de 8wriction between the tires and the 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 (.bmif6 *sgac- ipic3 bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore frictioci3 *mfbi-a(pgc6s i.n.)

  A horizontal curve on a bdj *ls7th,d 5a8h9rt /ttzm0bobsled 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, banked a*s.qjpzw np (evdq+ 74t an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is b;8,:kxuzhq taanked 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 st: yyk xn )-a.9wdv-qq /(xhimlring is revolving uniformly in a horizontal circle owl-y .qvxixk- h/:qma 9()yn df 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 inelv8ir1p (kz 0)+bmx g the pit area, a race car accelerates at a uniform rate to a speed of 45 m/s in 0(m pr1vbixz8g ) elk+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 consistqcc67qj( ey 9n-g2g jjs 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, due toh uf-vp /ko:. x:o;ool thepluhvo/o :k:- f o.;ox 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 attractive force be9hj 0ugn 91psetween two masses is F. If the masses are moved to half of their initial distans99pjeg01u hnce, what is the gravitational attractive force?

  For a spacecraft goinl +o vorru2h4::ivw ,d t5)flhg from the Earth toward the Sun, at what distance from the Earth will the gravitational forces du5 ov ulh)ilrw: 4+r ,f2:vodhte 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 8 9ph*0th*l+zpxrqgu;;wbim $7.4 \times 10^{22} \; kg$ 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 abcx5g75/ l;c,mu, k4m olgfjwdove the Earth equal to the radius of the Earth. What icl do5f,gu;/j4x 7mg mkw ,5lcs her acceleration due to gravity?

  The radius of the Earth is R. At what disg s-5wup y7f+vtance above the Earth's surface will the acceleratiov gpfu+y5sw 7-n of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abgb/,1 f;kb fh +5 yc+qseounm3ove its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to theme;yb/q1c,f5 h3f+kb+gsu n o acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center8 x pqsnhvh pn5f jwy -*2/vp :ogl,)af59ip.s, the acceleration of gravity a,o/n5-8jsf w9si)q5h pnv*gxh:2yp .lvf ppis $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N on the surface 63d:peqbpk;/ j pkvn+of the Earth. The Earth has radius r. If the object is 6n+ p3eqd ;k:ppvb/ kjraised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the sjl 1*zba6,tx weight of a 100-kg person change when he goes from sea level to an altitude of 5000 m? (The zs *lt bxa,j16mean 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 poin )(cvyj:;w;kicy+g zu t 3r above the Earth's surface. What is the satellite ykzc( +y):uwc;;j giv's weight?

  A spherically symmetric4mey(x0 lbvg+6yf1q kkn6;wmg9 p;dm planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much wq yb(fm;gvlg6kx01 p ;9ek ymm+46n dwould it weigh on the surface of this planet?

  During a lunar eclipse, th ;a 7o/z 00hd9vi ;qcqep3bosze Moon, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The Moon has a ma z/pe 9sqoi0hd;0oa7 cv3zb ;qss 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 transpormdy55p5u-/aden h/0q:.j azf/y ry egted 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 the Earth lhy a6 0xqem:t 8),drl(i.e., it just skims the r,)l8 ly0 xqdaht 6me:surface of 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 circular orbit abo9dai ).-hfsyvut the Earth (i.e., it just skims the surface of the Earth). How ly h)d9 s.iv-faong 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 the 5yjowo:4x8q tEarth. It is observed to have a period of 89 toj4ow 5y8:xq min. What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupi sfes(c +j/gl4ter, 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 orbimy c(:lc+ kh9:s1i qrats 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 ha+sjphw o1(g9 kqs6mdm- ,ldn 6s orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take m1-6(sjn9 dmqmgp hdsko+w,6l oon B to complete an orbit?

  The planet Jupiter is g)vl* riez - c1lthv/ 3ov.vs7$7.78 \times 10^{11} \; m$ 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 orbit5b5fu) zg,a af the Sun once. What is the average distance from Jupiter to the Sun? (The distance from tf u aab,5)fz5ghe Earth to the Sun is $1.5 \times 10^{11} \; m$.)