Is it possible for an object moving with a constant spqcb d.ds+73n ieed to accelerate? Explaic.is+q bnd37dn.

  Consider a particle moving with constant speed such that its acceleration of coa5s.8d r8 8b rpx:zse tzcm.x:nstant ma8cx::.zr.stdp8ebxm8 s ra5zgnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Comparebei -iygr o ,zlwe0,7zvmf3.* the direction of the object's velocity and037,,zzifble.m- vi gro y*we acceleration vectors.

  When an object experiences uniform circular motion, the directio/ucf i03,e .b6bsboso n of the acceleration i b/s ,f.ei obcbu30s6os

  Consider a particle moving with.nje9t9 qst ;z2j q-un constant speed such that its acceleration of constant magnitude is always perpendicular s99nqq-je.n2 tju; ztto its velocity.

  What type of acceleration dfgtacz1de m*hu)*vb wbc .*. :oes an object moving with constant speed in a circula)*.tbguw:cefamh*v* 1d .z bcr path experience?

  What force is needed to make an object move in a circle? fg*wnbrzz,; ho(n,. w

  When an object experiences uniform circular motion,m hzmtu5z 41cwsjz 0wjgx)b e0 4xd;.0 the direction of the net for5x10j4 .tz bm4z 0w)wjz0cmdesghux ;ce is

  A roller coaster car is on a track that forms a circular loop in the vertica+nbelm) venb*r 6h7 7rl plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centrine h6l7b+b 7evrmn )*rpetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a ci yu10-vz9 dnqprcular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the trackvqzy10du-p n 9 at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive tsqo v8w).ss ;tol) xh.hen follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest poinsol .w ssqt)8ho;).xv t, 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 o - 2vdtl usz//cew(;ar;w4mx)6qfemqf 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 r at a constant speed v. Then it goes ar axlwha, /s.ec7csl+4ound the same curve at half of the original sasl/axceh,l4w .+ 7scpeed. What is the centripetal force 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. Then it goes arounvm 7huy:erw+xe 9i+ 5fd a curve of radius 2ryurhi+9 e7+mfwe: 5 vx 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 ofzdfp42vb h: ddg:hfmtsw6a u7:ki d9 4fut166 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 k:id6 za6td274ff 1u 6vhmh94dftg wsbdu p::from the road is equal in magnitude to

  Two horizontal curves on ar+)d+tm pzni1n rk+ n*ey0d(7; sx e bb5xakt- bobsled run are banked at the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius cb75n+r -drm tn i+ nzkxd(t;pey+sex bka1*0 )urve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the O od/ 58o*pbmstlympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, 5 *stp /o8bomdthe 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 centrvakf1erz,( /ao 4i;ify6*p zeipetal and tak,*46raz/; ep1 evifi ozyf(angential acceleration?

  The gravitational forc*t ld0dw*ux3k e between two objects is proportional to

  The gravitational force betwe-k/m w vsu4-glen two objects is inversely proportional to

  Two objects attract each otherg4a n77w.mwgk gravitationally. If the distance between their centers is cut in haw4g.7w 7 mkgnalf, the gravitational force

  Two objects, with may br-o m;iha:7sses $m_{1}$ 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 ma +p.ch)r ,ga(e qcc+gisses $m_{1}$ 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 univebp98n h 7n dp)*d2xutuiliz01rsal gravitation.

  Compared to its mass on the Earth, the mass of an objecrk)j4p 5cvei(uh k 7. ehlikbn6877kat on the Moon is

  The acceleration of gravity *kv07qqi 4dl don the Moon is one-sixth what it is on Earth. An object l* kq dq0dv74iof mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocketb-*u.2 zkaigg b4cu0,xdqu qyc--( 0ag kb-qa's weight

  A spaceship is traveling to the Moon. At what poi0c0m 7/nlwba8 :dmq:tfzl x;xnt is it beyond the pull of Earth's gnlftd /wxmq0 : 0lzb a8x;c:7mravity?

  Suppose a satellite were orbiting the Earth just hxf0,r95kt,h2gl j6 nob8(qop pou. k above the surface. What is its86qkb5ghpfl( rhxj o,.oko 2, u9pt n0 centripetal acceleration?

  A hypothetical planet has a mass of half t0j, sntkv +*uohat of the Earth and a radius of twice th, o*0+nvkt ujsat of the Earth. What is the acceleration due to gravity on the planet in 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. The r +f/r 77 0k uumg:ca(wpovnb/cadius of the Moon is one-fourth that of the Earth. What is +(cm uacu/7wbo/kgr p vn7f: 0the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice9bdb/4ep vc 5frm7o 8j the radius of planet A. If planet A has mass m,5 b9d7pob8 vmc4/rjef what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mavceppp6 fz *(3ss of planet A. If plfpzv 6pc ep3(*anet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbk5m oy1i z7fs;u t+q2;;ijd oqit (radius r) about a spherical planet (mass M). fqi z;dqytm+ ;s157k;i ojo2u Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the s pw.xt+k8dl;eeaf 5/,5dgtld ame orbit. Compare the two satellite's spe 5ll txae;k. g5f ddt/,ep8wd+eds.

  A person is standing on a sca amc b b;xgq753 ju,gj4xfj5c(le in an elevator accelerating downward. Compare the reading on the scale tj(g7g5bxj3jfcbq mu;x a 4,5co the person's true weight.

  Who was the first person to realize that the planets move in elliptica; 8h .izxfphsqtz1niz)8 / cg-l paths aro-)c zxn8.qhpz g; zst1ifh/8 iund the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit k:+y6dkh hj44b9ifjh around the Su9hibjjy+h6 4kd 4f :hkn,

  Let the average orbit./e:8hn2;. o h4onrjf s7exak9jhb ipal radius of a planet be R. Let the orbital period be T. What quantity is constant for all p9r8k2op:;xjbjinhe e nhfo7s ha. /4. lanets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Androkb1f 8/wbtv 1lmeda, 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, compared to the Earth's orbital/vw t1kf81 bbl period?

  The average distance from the Earth to the Sun ip(; yj6 vxwe 8kkmk;)ms defined as one "astronomical unit" (AU). An asteroid orbits the Sun ikky;m)e8(px6w ;j mkvn one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.8xg60hkt70fu;81zhpakcr a s

  List the four fundamental forces in nac67 xpto62zxh qc 2 2lg14jtvvture.

  An object moves with a constant speed of 3bt +dkynk- *h+0 m/s on a circular track of radius 150 m. What is the acceleratio yh-tnk*k+ bd+n of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the ma0ry97ch.ytmim5o idzll72o ( 2 ut(rzximum speed around a curve wio7z0 oycr mz im2.(7(ilr9h5l2 ttdyu th twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter qbxk e :f8b,n7u:7 bgcof a bicycle wheel of diameter 70 :b8n7,7eub cbfq:gkx cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axh co2)e je)rvn1 p8os0is. What is the centripsc no0oj21 )v ehre8p)etal acceleration?

  How many revolutions per minu q3x*fn-*sh l*r -2 h+tq3ldgsyulul.l5i up8te must a circular, rotating space station of radius 10xi-ul*3tfl s5gh.l*8qlsrpq3*ln u +2 d yhu-00 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mpg1;sk6qqmkk1 n+i+lp: z8xg ass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. Whatmsp 116+:n;8 gl+pxigqz kk kq is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The systemfoqcc h + r5)j fna.)yvj5*dm, is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 350 N. What is the maximum s or h)),qf 55+*djjmccavfny.peed of the mass if the string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a ver; (6 pf-v-mbct2ug k y:phmnjty/ (ew5tical circle of radbc(5 p-;p mgkytt j:u fy2- 6n/wv(emhius 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 this point is given by

  A stone, of mass m, is attachedomujj ,c-a 3cch0.nnfjt 19e6 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 pj,31 9 tu-najfcce.0ho6 mncjoint is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out ososajsuys48*9 ;nb t6f the dive. What is the radius of curvature of the loop in which the p unyjs bos;ts *sa9648lane is flying?

  A pilot makes an outside vertical lh z36e9hfx mx:oop (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 36hhx m9ezf:x seat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about se(z6bi .:xr spqvzy g-6ven times his weight. What is the minimum radius of curvature that a jet plr .g:s(vpqyiz6z - 6xbane'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 ti )2tzm hgc;uql 55yw5rres 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 tire 5 t5)yhqzl;c wmg52urs and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The celz5dh,pz. zg betb91ye k+52mntripetal force provided by friction 15 hzyt5zez gd,bkm+2 l.pbe 9is $1.2 \times 10^{4} \; N$. 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 m tockjqdmk6zjrqdnm6d: ,9f /)4 y h/.ust be the min qk)j/nr,:jmz9qdfhc4/ 6 ydtm6ko .dimum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant s 34xetl+wmde4 peed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the car is to stay on thlm +ex4t4dew3e road?

  What minimum banking angl pek*,9zpc qul 4v0ax8e is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s wit,zc0qauxk ep8vl94* phout skidding? (Ignore friction.)

  A horizontal curve on aoii p7u;k0qn5 bobsled 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 at an angl7 f-:wjbl8 cjoe0wq3 -noh0gq cx.vb2e of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked aty8f ++j6phc vj $45^{\circ}$. 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 revdl8,q6,6upf9j caxc ml q ft2(olving uniformly in a horizontal circle of r c,lltm6, c6 uf p9q8fx(aqdj2adius 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 accelerat a;+1ixefxj:t vv ht0* npb1t.es at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fillnti1; t v p +x:1*fjxt.b0aveh 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 m:s9srkxuok u nbkk-+h)d.: 1nk d*an8ass $1.67 \times 10^{-27} \; kg$ 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 p5z dxc74m g0(lyqv) nbsb/y 8Earth, due to tb p78x lg 5(mvzb/d0)y4nqyc she 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 forcui+doit- ce;4 e between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive fe - iiod+t4c;uorce?

  For a spacecraft going from the Earth -m+dg0 d :gkwstoward the Sun, at what distance from the Earth will the grdd+s 0 w:km-ggavitational 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 u9.q 70z5 f c-/lt6wmcrjs7qdx/ iicn 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 ou 6q)b830gu 3f qffro.s;4xojism -f qzt for a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration due t 68) -fxbqq; ji z3 ffmoq0ufgssro3.4o gravity?

  The radius of the Eart t66d0llj tsj:h is R. At what distance above the Earth's surface will the accelerati:jdl 6l stt6j0on of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times y+lc u(6 tdf3vthe radius of Mvfut3+(d6ylc ars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of ixp(g38o b +wwgravity is wo+gb (i83w px$32 \; m/s^2$. 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. The Earth has 0v)sy7b ,wh8ce0zq jd radius r. If the object is raised to a height of 3r above the Ead)w q0eb0 c7 8ys,jzhvrth's surface, what is its weight?

  By how many newtons does the weight of ary8wa.eme;.*jn p (8gwls5xl wmm 2/f 100-kg person change when he goes from sea level to an altitude of 5000 m? (The / wn j5p.m(grl amfs.88;eml*x we y2wmean 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 ab5e3d*i1 cf *6 ++bvodjwgfiv rove the Earth's surface. W3j**c id+ gv fdie1w vf6obr5+hat is the satellite's weight?

  A spherically symmetric planet has four times the Earth ooiw3,hm:zf )'s mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how z)o,m:iwh3 of much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, w4 0o*ezxod1 qcith the Earth between the Moon and the Sun. Tdxc 10 oeo*zq4he 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 ;qcz :,ov)l) (k kljumis transported 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 loj qmv1f6.q( : hptae:mw circular orbit about the Earth (i.e., it just skims the surface of the Ear f(6m.aqtmqvej:1:p hth). 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 circular4rt .cusc9e y0 orbit about the Earth (i.e., it just skims the surface of the Earth). How long do0.eucy sr94 tces 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 circus 4 bo-a,c.t.x7ej+ff 9ec, moh 3isjular orbit 230 km above the surface of the Earth. It is obs m c,.aco-ojb9f.es+u4fihtx73jes ,erved to have a period 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 diametervrkqmsc;+ p *; 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 rado19fyo mpgwx(75pip(o);t m e 6jw4yhius 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 orbibxqb; kup.9p0 ts. Moon A has orbital radius r, and moon B has or;.x ubbpk p90qbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is pkw bg5q-k72x $7.78 \times 10^{11} \; m$ 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. What is the averagqq (1l k*dibq//wgafc+4ks+te distance from Jupiter to the Sun? (The distance from the Earth to the Sun is qk g /slf4q1w*tq b(ai/+k+cd$1.5 \times 10^{11} \; m$.)