Is it possible for an object moving with a constant speed to accelerate? Exv.zbj /jt04dejp*v, tplaid/*0bj t .j,v4zpetv jn.

  Consider a particle moving with constant)(c :nzwh67*ikcf rxw speed such that its acceleration of constant magnitude is always perpendicular to its velocity*i c6zchk rnwf:(w7)x.

  An object moves in a circular path at a constant speed. Compare the direction onzzjq(, kt,n61q7x ia;f4jzof the object's velocity and acceleration vectorsi1z4o,z6axzj(kq;f qn , jnt7.

  When an object experiences uniform circul x)y(t/8 d mndd2/cdwl k7o-ehar motion, the direction of the accelerate mh/l/kd8oc )ty(w d2ddx-7n ion is

  Consider a particle moving with constant speed such that its acceleration pl )dy+uuy4f :7ug(+wrhfrajd7(o5 w of constan+r w5p(h)yo d4 ra7 w:yfj7df(ul+ugut magnitude is always perpendicular to its velocity.

  What type of acceleration does an ob(f;6xfyry :-ojcprd ol 2juw,v.m3 e8ject moving with constant speed in a circular path exper y mjp 2 6l,:wd.o(c rvjuo8yf;rf-3exience?

  What force is needed to make an object move in a ck5 hno7qtasb1gg w4) ul0w8) wircle?

  When an object experb:he +2ypq0+gq vs4 t,jkcic4fh n -y+iences uniform circular motion, the direction of the net force h4iyj p,ef4 ++nq:cq -y+c2s0kvh btgis

  A roller coaster car is on a track that forms a circulacshfjjb+e7h; qx e)9zn6e 9w/r loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimujb7ejh) fe 996/s x hq;zcenw+m value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular 7/z ;owtt;*3pwey zvnloop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at thtzt;np v*y73 ze/wo;we top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semicjcqf) (q-0gx-circular arc until it is going straight up. Just as the plane (q0g-)ccj qxf 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 r ;qxyq rbi ++ks6t .0jd1oh-zoadius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of 4;j p9s; j8du py7eozgradius 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 curve ozs;7j;jgupy de 8 p94for the second time, compared to the first time?

  A car goes around a curve of radius r at a constantwsw gfcb5-j9 j.x:epdy y812w .oy-dq speed v. Then it goes around a curve of radius 2p cwj y.:syfg1dd5 9eqy.wbxwo - 2-j8r 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 ;ldo*l5qz1 y*bw5e jj idm;vh.f 6ax+radius r with speed v. If the road is frictionless due to ice, the car can still negotiat155iolv .wy;6* xhzqe*lfmj bddj ; +ae the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same anglfc) pwpz5l /ng.mn.5is 69 lqle, 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 thfclw. 96.nz)p/pi5smq gl5nl e safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constantk85c hn +1g,u 8 yda.zmaq7+cuvptq/n, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower comingd+ n/yhkn8v5zamuquc a+q .g7tp,c 81 out of the turn. Why do they do this?

  Is it possible for an objefn2lqci w .yd.oj94:g xt) ;uoct moving around a circular path to have both centripetal and tanc:;9) fdyoj.g .ox2 tlun i4qwgential acceleration?

  The gravitational force between two objects is proportionalm fx,v.4 8wnav68xtu p to

  The gravitational force b cc6im0 u+2h/ ewhtwk y)6dr+fetween two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distjgj4(spkl, 1xbz(g ,m5k eih6 i v5da0ance between their centers546b (jv km(sp5iad zh l,ei,gkxg0j1 is cut in half, the gravitational force

  Two objects, with mazmj b(7iy o)t;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 masse7 ivw*) e a7ihgi,xp3bs $m_{1}$ 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 zcqql/9rv :l*f xi*u:gravitation.

  Compared to its mass on the Earth, the mass of an object on thdk0j /3 aa7.f/ubqctde Moon is

  The acceleration of gravity on thjx.n7.3nca7tdm vjt uc s)r *6e Moon is one-sixth what it is on Earth. An object of mas6anj 7n)ruc t*.3dvt s7mjx.cs
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, t -jyosdxefyly6 whdwrq9 2f,19 g 35+ahe rocket's weight

  A spaceship is traveling to the Moon. At whaqwbs .8(n;qfqphs.3 ag7md- tt point is it beyond the pull of Earth's gm7 s;bt (agqqp8sw.q3. fd- nhravity?

  Suppose a satellite were orbiting the Ea.u5,/xslkdin+ 8 auoy rth just above the surface. What is its +uxsnau doik5y./,l8 centripetal acceleration?

  A hypothetical planet has a mass of half that of thf8 8mdl4xbu qong) )b.e Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet ioq m84n 8lx)g)bd b.ufn terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. T+ uq51v 2ggau4.3pck8w jjekthe radius of the Moon is one-fourth that of the Earth. What is the Mjvu2 +tuj5qkck3 4g.aw1ep8 goon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the radius of jvndu-ioy:6)o2 a5 r oplanet A. If planet A has mass m, what is the m aoodr6j -)nuoi5y: v2ass of planet B?

  Two planets have the same surface gravity, but 2w ne +n;hgr7z yze nf:k2,jii lc;7r4planet B has twice the mass of planet A. If planet A has radius r, what is the radius,jhfrrl :2+e;we4zg2 i yzn7 7 cnikn; of planet B?

  Consider a small satellite moving in a circular orbit (ra ctb x:39uic: )jo/s.x,u ibpndius r) about a spherical planet (mass M). Which exp.icut p,c xxji3bo:b /ns9:)uression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and r6ub,. r jqpzyyj 05q/potates in the same orbit. Compare the ,q6rjypbj0 qz/. pu y5two satellite's speeds.

  A person is standing on a scale in an elevcsy;k58x3dv5w ; zf hkator accelerating downward. Compare the reading on the scale to the p 3kf5 w8cxsv;zkydh5; erson's true weight.

  Who was the first person to realize that the planets move in elliptical :2y* (lgwwhu 9gc +yr,h1 otexpaths arouu(ht2 o gle+hy,ywgwcx*1r9: nd the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit aroig erbh-s3 ;p m3jp xc2*1)y9jfsxy0iund the Su - ip ;fbcx3m3x*sg19r0) h ypyejj2sin,

  Let the average orbital y-zz5 ei1ib 7 e98vmh1ca.lzaradius of a planet be R. Let the orbital period be T. What quantity is const z a1b.1ez 9iye5 -cz8iav7hmlant for all planets orbiting the Sun?

  A planet is discovered to orbit aroud1eybtaw 7n.i-8yq ( p ),pjlf:mup .nnd 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 revolution of that new planet be, pa,(ful7qije1y8dpmtn.y p)n :w -.b compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "a9 ,v 0rdmau24opudb f:gg6 /fqstronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the as ufpavgd 6rqom/b,d0f u:g942teroid's average distance from the Sun?

State Kepler's laws.smt o953dyw rz r6ajjcj.-:d2

  List the four fundamental forces in nq ymgf -la4 )9:mpf.cwk/rj 4mature.

  An object moves with a constant speed of 30 m/s on a circular track of radius no rg y8(7li,x(i:o5d(xc jbo150 m. What is the acceleration of tloyo,:xo8xgc j5n i(r(7i(bd he object?

  The maximum speed around a level curve is 30.0 kmckkt. o6r/,ah 0c;/cq ax+myj/h. What is the maximum speed around a curve with twice the radius? (Assume all other6 hmract c/kx,./cyo0jqa;k + factors remain unchanged.)

  What is the centripetal accele0jz687:fyrnywu- g 0hs 2)c4hso pyoxration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s? x 02o0urgfh csy4sy)hn8:7z- 6 pyowj

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the k0qcxhj /bq *o vk76q:pkv jq.zh1*3jaxis. What is the centripetal acceleraj*zhvvqx 7.qk:kjkq 01* qobj6 / hp3ction?

  How many revolutions per minute must a circular, rotat 7v/md00+;tgb 2qdpmbjkr ,tting space station of radius 1000 m rotate to produce an artificial gravitykptmd/g jv2r,0 t;0+ mqdbbt7 of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 dsq sj yf+6,cjpn 081vkg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetal force on the motorsqfypcdj0s j+n8 1,v6cycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The sysua)e)y h, n6gttem is whirled in a horizontalu6ag,nyh)t )e 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 attachg8c co8map (z99j scw1ed to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3cjpg1 a(9m8zc9w c8so 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 in a),3zfv fy*gaa vertical circle of radius r. At the exact bottom of the path the tension in the string is 3 times th,a v*3)zgay ffe stone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/6fds sx7d)y :vj ouo1/vd9+bdfr2 c 2os experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyiv:1ud9o 7vrscyf2 6sb/d+do) xfd o2j ng?

  A pilot makes an outside vertical loop (in which the+ljaw c7qv6iw9wnt4*gdo 9+q 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 7jwdi +t9w6w aqv+lq *c9 gn4ohe going?

  The maximum force a pilot can stand is about seven times cb g;qwjj 9kl fhi8)l./ f9ln.his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical div l/gfc wijbfklj98ln)q; .h9 .e, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal ce ir mgejrf- /( n;9cx5ndzt4(urve with the tires 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 ti95rdgrfi4ce;nemz jx(t- n/( res and each road surface.)

  A car is negotiating a flat curvsb+e9+p i 7emqe of radius 50 m with a speed of 20 m/s. The centripetal force provided by fr bq7+mp9eei s+iction 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. What mutn7eat 4 joiq 3q9q -c0owilld*lv5-1st be the mini9i qttnq7 wdc ol4j-*aq0lo1l5ei 3v-mum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. ag 2ad/r,mxx00wfdi1The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve gxfda2r/ x1 mw0adi,0if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate t:)lje de4z5mku /t(h a 100-m radius turn at kz4/uj t:dlt (em)he535 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled xy(w+/skl78xc, jfaf ,hy 0kd 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 gfr0/se**+n0 h sdhbg9k wgxug3m u67at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i 1g- x-gg c7vhg8./ixjyygi6bs banked 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 revolving unild6,xq p/ r6p+v;/;dsvojny gformly in a horizontal circle of radius 0dvv,dsnpjrq;;66/o+ x gp l /y.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 piuyj pq2.jl*4jt area, a race car accelerates 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 value in 2yj jq.4jup*l 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 -q1 zxc+b xk7cof 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, d8jevoi 5eel2 fpu0 ;t7ue to the Moon? The mass of the Moo 0p8 u7fe2eiov;ljte5n is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force betwu 53u 3wbxcgv kj77go j**,1w/v gdgzbeen two masses is F. If the masses are moved to half of their ink*7/ g w jc*jgb1 zowug,gdbu5v 7x3v3itial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distxpkmyeoih * 0fv7*wyn7.9c:kance from the Earth wi:w7k xch9 *p7.*ni0eyokfym vll 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 4s)i. pw p4 )hkic6wuyis $7.4 \times 10^{22} \; kg$ 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 Earth2:a y0 itd80fft iqe1i equal to the radius of the Earth. What is her acceleration due to0ift ft1q0ad8 iie2y: gravity?

  The radius of the Earth is R. At what distance above q:ussp w wdt13 uir4.-the Earth's surface will the acceleratiopu r1: tudw-ws43si. qn of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 t1i;+u8.y bw9(f oxgo fp f:umkimes the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on ui.m9p bwo+ff k;xogy 8(f :1uthe surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gravitxp e1,fm6 h1 y*bi,/ aw0pmzvwy isxm w*vb pwmeip/yh,f, 16a1 z0 $32 \; m/s^2$. 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 Ea ozixh;ew-- l6rth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface, whato i;wxze-6-h l is its weight?

  By how many newtons does the weight of a 100-kg pev18, 1ck tjmuqrson change when he goes from sea18j ktqm,u1 vc 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 mass 103wwswrb5,ac yp3 g g+ n:b7mr)0 kg is at a point 3r above the Earth's surface. What is the satellite's weighy), gw37sc rm+wagr3:n5wbpb t?

  A spherically symmetric planet ha3ad+fo 4p, 4b-w7iubnohth a;s 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 would it weigh on the s;wobh47 u3 4+,n fahioa-dtpburface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same lini nh6e32u.4sqr 5r knve, with the Earth between the Moon and then.5h v3 uirsre2qn6 k4 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 th n9o8dkl)w lp:e 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 lo613jh0 soi(cz yj6yh2 xqr2 c)9 beyfuw circular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius 6 hfc qey)royi1y 0xjucjz6s322h9b(of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit aboukng9 v, 6( sr+0vq pkbl--qcipt the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one repkvr(k 0+vc -ilg -6p,nbq 9sqvolution 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 Eaiqv 7cc a3qi:me)a1lef5 +o.e rth. It is observed to have a pe:me.li +q e1 a73cofeqivc 5)ariod of 89 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 Jupiter, has an orbital diameter x *kvksc-qk .,fac x7fftcwjd38.lb o:;7c+ eof $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a radiumu7p bznk5so ,q2( s:gs of $422 \times 10^{3} \; km$ and a period of
1.77 days. What is the mass of Jupiter?

  Two moons orbit a plane22;hcqbwho t x994 .pjo1v ymit in nearly 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 l;2my.itx4 v21 q j oh9cohbwp9ong does it take moon B to complete an orbit?

  The planet Jupiter is 1- bwwkplea ,/$7.78 \times 10^{11} \; m$ 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 Jn-2cj -d c+2-gnixkqnupiter 12 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance from the Earth to the Sunn d+c2 -ikgnxnq-2cj- is $1.5 \times 10^{11} \; m$.)