Is it possible for an object moving with a constant speed to acczr+ .y i+ j(hv9vo:fgkelerate? Explain.v+zfkh.j(r9gvo +:i y

  Consider a particle moving with constant speed such that its acceleration of co.a7:b qwcb8u2x0 ke jynstant magnitude is always perpeb27w:axbq.0 cu ej8 ykndicular to its velocity.

  An object moves in a circular path at a constant speed. Compare7.q xr+ v(gkz* c2h;ob stq p*jb5c9kl the direction of the object's velocity and accele7bg2pk+rxs.l h9;ojq q*b t(c*kzvc 5ration vectors.

  When an object experiences uniform circular motiqmw/: bc yfl -tw33g;+i. hqlgon, the direction of the acceleratiw3 imhcbqw3+ .-;y/g:tfl gqlon is

  Consider a particle moving with constant speed such that its dv ;zt6zl l wz69a:fh0acceleration of constant magnitude is always per:v9tza ;fz6 h w60dllzpendicular to its velocity.

  What type of acceleration does an ixj 2 h(kgpb5;object moving with constant speed in a circular path expe; pg2jkh (xbi5rience?

  What force is needed to make an obp *bvnaju +42lject move in a circle?

  When an object experiences uniform circular motion -6gle, rmqrd( *hor6b4ut j)s, the direction of the net force i(e 6hoqt 6s gu*jrmr) -,4drlbs

  A roller coaster car is on a trag-.g5 +juexi2efo.z t,c o n7al1ian. ck that forms a circular loop in the vertical plane. If the car is to just mt 5j2uoe g gae+xfc,al. 1no.in7-.ziaintain 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) jz 4jlk69sy4hj/z5l p is on a track that forms a circular loop (radius = r) 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 tha9jljjp4hzy4 l6kz5 s/t point?

  A pilot executes a vertical dive then follows a semi-circular arc untgq0xyc3d kb )t66 pq2lil it is going straight up. Just as the plane is at its low0 qkp3g)y6l6b2tqc xd est 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 radwpf*wyl7ho1 d8z 6,t+(gl8liy yppf*ius $r$ 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. T)m t um+t:nzrjoe6v9. hen it goes around the same curmz :.6 ounvjt9et+)rmve at half of the original speed. 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 radiu7 pd.xw er5s9es r at a constant speed v. Then it goes around a 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?.e5d 9wsxr7ep

  A car of mass m goes around a ba:l6zwaap/ i /tdtv/+enl ln ;0nked 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 normal force on the car from the road is equal in magnitude tv/:nla 0/ltn e/p z;it wda+l6o

  Two horizontal curves on a bobsled run are banked at the same angle, but one h )qhv x tfldsqq ,ey d,np7 wc+txb73zn0j7.:+as twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller rq )vz +nt,:ltxy +fcdp.wq7e,s0773dqxhjbn adius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled trjozc;hijhr7 : u7muy5c*2 6mf n,g:ci ack is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower coming out of jizm:; h65fg j ,:7h ucc *u7conmyi2rthe turn. Why do they do this?

  Is it possible for an object moviypin*64z l)a-u-1f( cbc *hx1 vbnimyng around a circular path to have both centripetal and ta4-1zny acbb1- nv iy)mfhxu*i*(6lpcngential acceleration?

  The gravitational force betw+hkd;/0z bo)aj)bnsn; lf:ai *. ahyas)ue ;teen two objects is proportional to

  The gravitational force between two 9rbs (r3gd+ incm:bn wi8*y.hobjects is inversely proportional to

  Two objects attract each other gravitationally.muf(a,7 jftr3(8 mk rd0mp0em If the distance between their centemdrj8(ua7k mfmf0 3e(tpr m0 ,rs is cut in half, the gravitational force

  Two objects, with makgkdgjuqn cw:/9ic + 4;-nrc0sses $m_{1}$ 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 mag v3a3bgc-vu 5sses $m_{1}$ 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 gravitatio8.yn8 98btucy,c5eavz4c vgin.

  Compared to its mass onyk/(w()svjiz;os i * k the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon iso2zqkthdz 3mp+ g8)f- one-sixth what it is on Earth. An object of maz dhz8 t+ 3mfkg2-oqp)ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earthp2:d*vuw5 7lyag dybdm p20a3 's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point (xgycf1 *v7zu cselps)s .lg;/ 5r2dyis it beyond the pull of Earth's gravi /dv2;)r.cusxeglyl sc5p f ys*g7z (1ty?

  Suppose a satellite were orbiting the Earth just above the sur2bqa:zstsb h a,/ 54ijbj :,qrface. What is its centripeta q:tr bj,q/ ss42zh5jbi ab:,al acceleration?

  A hypothetical planebs ehms0))3d tt has a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to grh st3bs0 md)e)avity 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 wh- z7kt3vlew72 ur(x ovat it is on Earth. The radius of the Mo3lt xreo27kuv (w v7-zon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice u ylzia8 /b9)tih)yu7 the radius of planet A. If planet A has mass m, what is iy /i)ul9yt a h8bz7u)the mass of planet B?

  Two planets have the same surface gravity, but planet cl1; l7gxqwh:vf:fi:p-xe y/jg, ;prB has twice the mass of planet A. If planet A has radius r, what is; q7f:xx1ghfp,ye-v;rcl/ :w i:j lpg the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) aboui *gu j, 0ou8 gn2lhxij6o7 6cjgv,y/ut a spherical planet (mass M). Which exp* g jg ,uu0giy2o/ujh nc,o68l jx6i7vression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in thep zi.vy zu7(v9 same orbit. Compare the two satell9vp z.(vzy7iu ite's speeds.

  A person is standing on a scale in an elevator accelerating downwardg(0 *n zb6:rh ntwi;sewu/no 3. Compare the readin6:n t0er(wnw*ion/ g3uzh;bs g on the scale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical pk pzl) l8s:e6sij+ok6aths around tkpslkjz+ i6)esl8o: 6he Sun?

  The speed of Halley's Comev,wd j3*q;)sz -8y/kaa4p d nd9xjpkw k 11ubgt, while traveling in its elliptical orbit around the vydpkgdp,q kaw*3j)1s a jwz9d;b4n x/8ku1-Sun,

  Let the average orbital radius of a planet be R. Letc 1d2rfx9ib;dqmw / o0 the orbital period be T. What quantity ; b1x9if 0md2w r/cqodis constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andr(gaa)ph0pk.qw h0t4 zomeda, with the same orbital diameter as the Earth around our Sun. If that star has 4 times the mass of oura(w.tha phzg q00 kp4) 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 "astr+7u;o 9 fh22wo q97t s bnc3snlw/hoxgonomical unit" (AU). An asteroid orbits the Sun in one-third of a/ fo9n7us+b9l 2scw3xhh2t g7ooq; nw year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ji5qfg;t*. ub

  List the four fundamental forces y*fzf reh+rlfj;mv+,hdy51 4/d 7e qoin nature.

  An object moves with a constant speed of 30 m/s on a circulocs92k :ok b(eaci,sc/ 1d p;aar track of radius 150 m. What is the aco1p /kco sbc:ci2,de9akas(; celeration of the object?

  The maximum speed around a levr)i0yg- f1zb+ )* wv3f rqcwkvel curve is 30.0 km/h. What is the maximum speed around a curve wi03f -bw 1+ irz kqvvfr)g*)wcyth twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a pointl4u , 7 rrb tugolu+l:m65kt3xyz*, qk on the perimeter of a bicycle wheel of4uur,byx7:k6 utt* rq,+5g3lllomz k diameter 70 cm when the bike is moving 8.0 m/s?

  A point on a wheel rotating at s-az lpw( *it(5.00 rev/s is located 0.200 m from the axis. What is the centrip zwtpila (-s*(etal acceleration?

  How many revolutions per minute must a circular, rotating spacg18v-q sepq86s4)vi9+ go,hl ldsoi ne station of radius 1000 m rotate to produce an artigdq- ss)8 oi i+qvgl46po v89sl1n,heficial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It mooz6rq -awztpz 8/o7n4+ ks 1p;o1tl goes around a 13.7 m radius turn at 96.5 km/h. Whaaz47 kl oqoz+8p1tr/-n1moz ot6 p ws;t is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to tvex w*/cw5)fihe 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 speed of the mass if the string is x*f/c iwv) 5ewnot to break?

  A stone, of mass m, is attached to a strong string and whirled in0v)w:ml -oji q7,hg gg a vertical circle of radius r. At the exact top of the path the tewig 0v7h:lgg j,qmo )-nsion 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 attached to a strong stri38vat g,e db5jt3 za-png 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 j8 -aad5tv3t3ezpb ,gstone's weight. The stone's speed at this point is given by

  A jet plane flying 600 m/s experiences an accelerat6sfcdl5edxn e9tpw oi x h ,/.+3i)-qcion of 4g when pulling out of the dive. What is the radius of curvature l6)-,.id+o9ec/wpe fcdqx thn x5 3siof the loop in which the plane is flying?

  A pilot makes an outside vfltsf9(+ +di sertical 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 weight. How fast is he goingt(l+f+ fi9ssd?

  The maximum force a pilot can stand is about sezn/st2d9 -zmntfj n.- ven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a ss/nd9 2.z- jtnn-f zmtpeed of 250 m/s?

  A car traveling 20 m/s rounds an 80-pc * d0lxyu+i)m radius horizontal curve 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 tires and each road surface0)xcild *u+py .)

  A car is negotiating a flap:br +(jhm ,l1c -1* tdouxxogt curve of radius 50 m with a speed of 20 m/s. The centripetal force provided -,mold:1 (+uhbx jotpr1xg*c 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/fok 4(f; onxlxgzsc+6 si 2v.;:hl5x js. What must be t .l 5+:j2; k4 hl(ffvicsxxo6nxgs;zohe minimum 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 lev4p v-mgl)wv1gel curve. The coefficient of friction between the tires and the road is 0.4pg 1lvvw 4-gm)0. 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 i .g 1bm0a/1gllf*ittzq 9os.bhjg0.bobsled to negotiate a 100-m radius turn h0abl. g 10gfit/tg*s . j.zo9bql i1mat 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsbow :i1ib:l i7g/ tok-led 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 yx,+2yy py(uv7nn6 im7 zpd 0nda 3dh)m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80bzc 0;phc q+8 m(pq,jo)jh,kz m is 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 uniformlyz373asen; w rzgo9, h c0pqmbrp;i3f 3 in a horizontal circle of radius 0.egm f97npzis3,qbr;;ca 3 rphz03o3w 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, 2*8s ff pc(7a *zgmhoma 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 the blanks) om *28f(zg mpf hacs*7
(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 mass,45+2,fh no y qm:ze6pzfhi,f+ gmdim $1.67 \times 10^{-27} \; kg$ 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 gravitationgmc e h0sfv*r *29tuan:j4es3al force on a 70-kg person standing on the Earth, due to the Moon?m r 3se9j*s4v2nh t*gau:0c fe 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 between two mass4tnfac 6) g7ines is F. If the masses are moved to a)4nft6 n7g ichalf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from t :h/ ovrpgm o9c;dc0w+he Earth will the gravitodc 9/g:+o0 wcr vmph;ational 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 m4 xiv.r2;eg8(nckq0 /vkjv v 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 above the Earth equal t lm7zw1 9gcxd6q0iq/xo the radius of the Earth. What is herqz cxgw07d/m 19x6qli acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's sur nj,upg(h m;,*jt;h-m)g xa lfface will tn;hxgm)(j-*jtla u h g;p,m ,fhe acceleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distancer* 6e2 alp zw eg6fv9gu58dpqk-7r,ja above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compga8z ,6f 2p*r-v5p9ew7k rqe jl6g udaared 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 gravitypl,o ;xr+ jbe.yz/w)i+z/ pwl; j.)ryob,ixe is $32 \; m/s^2$. 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 thnbn3 ic5l b.4me Earth. The Earth has radius r. If the object is raised to a heightn4nc.b 3ml5ib of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of:0xgp o wot./b,q ,lnu a 100-kg person change when he goes from sea level to an altitude of:wnbp0 x. o /lt,ugoq, 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 po3.c: buahs8yyint 3r above the Earth's surface. Whabsyy8.:a u hc3t is the satellite's weight?

  A spherically symmetric planet has four times the Earth's marp v9v 58wji1kss 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 suvvw 8jr59ki 1prface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the sameuffe-u5pt in t49 b(7j line, with the Earth between the Moon and the Sun. Th9tn5ijbup f47t- uf (ee 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 the1hlru klv o:gsvo.rt +* r3257t7 hrti 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 m95j0k wh9h8ogyjv.1 7 *g9zayianak about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? m9ka8z. hj w k7o 9j5g1*anhy iga0vy9(The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the 8)jjo8lxr2a; -53am gixotcp Earth (i.e., it just skims the surface of the Earth). How long doesj5 2oi-8;m8 g aocr)3xjatxl p 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 /(ng t53,uy atrk5(stke,xrvkm above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Ea,(53rky gkxsa5 /, ttreunvt(rth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbit9mjpkwq;dhq4 .c3q e 5/1fxsmm )q(znal 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+;f k fgb3nmo7 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 has orbb a+re ;7h6ttsital radius r, and moon B has orbital radius 4r. Moon A takes 2es7ar h t6;t+b0 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 5jwdd1a)y1.9ulg njx4ed7 gp $7.78 \times 10^{11} \; m$ 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 thedu2 w b:kl)p:.rug lj7 average distance from Jupiter to the Sun? (The distance from the Earth to tdkglb)lwu u.27::rp jhe Sun is $1.5 \times 10^{11} \; m$.)