Is it possible for an object movi4l, kp3 ((qy0;yq vqivdxn*hvng with a constant speed to accelerate? Explaiqkh3y vqv,* l4(vpi(dq ;xyn0n.

  Consider a particle moving with cm)s6;k u9q :tkz.k obdonstant speed such that its acceleration of constanktmk us q9oz d.b;:)k6t magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Comn -r hb1 i)4tw3p)f rxkjo4hbj yl;h,2pare the direction of the object's vei 3 ;y4f4-ljr bno1bwhk,htjrx) p)h 2locity and acceleration vectors.

  When an object experiences uniform circular motion, the dir:3c 2jpog. chh :raic+ection of the acceleration isra 2o p:ic3.cgjhc+:h

  Consider a particle moving with const d .,1cf0d8sua gcwz2want speed such that its acceleration of constant magnitude is always perpendicular to its2auwsz1d,0c w.g 8cfd velocity.

  What type of acceleration does an object moving a;6(,bbydtn j nvyj0 *qzrn29a 5 mcy6with constant speed in a circular path exp cjbjd9;qaz v 2ybn5n6 ay*r0,n(yt6 merience?

  What force is needed to make an object move in a zptfu.+gg9-j circle?

  When an object experiences uniform circular motion, the dirdkhc2ul*i* bs3w mc1qfx2.v, ection of the net force h.2m,k*sq* 1di f 3c x2wcbvluis

  A roller coaster car i py*;8n/rm2uzv.zc c hs kcs+5s on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the nrk /cz2z5usypc*vc;8. +shm minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that formh)j or wpnvp/me1u(92s a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of th)(our/ ppmwv9h2 n je1e loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a 2gxowap 20 n9isemi-circular arc until it is going straight up. J w0i2xa n29gpoust as the 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 radiu-vg+z6cex8 xbp l,qsidv 6, j*s $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of radi 1wmqr,h6)k ihus r at a constant speed v. Then it goes around the same curve at half of the original speed. What is t6h 1iw k,mhr)qhe 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 aro+bu-mu x.gf;(k9 es lpsai88ound a curve of radius 2r at speed 2v. What is the centripetal force on ts 98u-blxm kaos . egp;(+fui8he car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r-ip tng6os6cp 41kve , with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of 14nko pevt- pi 6scg,6the 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 angle, but one h(ktymt62hr1k vys 6:has twice the radius of the other. The safe speedrth6(k 6 1 ysyhmvtk2: (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 bobs7qjmpzr80( oyled track is not constant, but increases upward from the horizontal. Coming around a8m0 q7y zrpjo( 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 movingw7vh ,qu5:egw around a circular path to have both centripetal wg,wqe7:hu v5and tangential acceleration?

  The gravitational force between two objects is proportional tomw.5 yymcnrol n5vg kk;. hsb;t* :5f-n3d3dp

  The gravitational force bey).zu mq;pnn.uz.. s*eluh j7 tween two objects is inversely proportional to

  Two objects attract each other gravitationally. If the distanceybcz,4ps5l g / between their cz5gs plc4by /,enters is cut in half, the gravitational force

  Two objects, with masses nv6ad vg -*gbbb-+w(y(4syks$m_{1}$ 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 massexpbf lv-j: csle (f.9/c yq2g:s $m_{1}$ 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 univerebkv9e/9i; mcsal gravitation.

  Compared to its mass on the Earth, the mass of an object on the Mooy((4qootrcxxp1 s6d 0bu/h u/n is

  The acceleration of gravity on the Moon is12q0q;ibmj xo os fz14 one-sixth what it is on Earth. An obo ;0q bz11ofi 2sx4jqmject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the4c)k6c (c0sr6d t/ 3 xybhmlpz Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the p7 o1wicr.. wtbull of Earth's gravity?brc..iw w7 ot1

  Suppose a satellite were orbiting dv7f0c3b x,y); gulwcthe Earth just above the surface. What is its centrip 0;,vfw)3ylcucg d7bx etal acceleration?

  A hypothetical planet has a mass ofgeyu*g4c597 sh;iqqj/mp h6 p half that of the Earth and a radius of twice that of the Earth. What is t5qy9h4 p*ic h7pjqg s;6g/ umehe 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 isuby( 4j z;chy6 on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass b(jyuh4z 6;yc compared to the Earth's?

  Two planets have the same surface gravity, bwk w04.tj qq: mjqhvagv 5:b7.ut planet B has twice the radius of planet A. If planet A has mass m, what is the mjt v .7q:a mwj .vkbq0h5qw4:gass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass6 6rv;/ummpad 7md8 xd of planet A. If planet A has radius r, what is the radius of planetv7xd/6d ;6maum drp m8 B?

  Consider a small satellite moving in a ci6u 0 0umiyoet+klg5 +e 1qo f4/lnxd)grcular orbit (radius r) about a spherical planet (mass M). Which expression gives this satellite's orbital velocg/t 4xeung)dq0 +me ok1lo0i y5+uf 6lity?

  Satellite A has twice the mass of satellite B, andjvs1 obw x1)n: rotates in the same orbit. Compare the ) svx:n1bwj o1two satellite's speeds.

  A person is standing onl3ull(zol*nx.6v r ;l a scale in an elevator accelerating downward. Compare the reading on the scale tnlzvl( lr3 xl6;lu .o*o the person's true weight.

  Who was the first person to realize that the plao:k-zdsgg ok42h5* ohnets move in elliptical paths around thoz5*k2d g4gskho o:-he Sun?

  The speed of Halley's Comet, whxjgq yx:f*1q9ile traveling in its elliptical orbit around the Su*q:1gyf j 9qxxn,

  Let the average orbital radius e* xen+s.w,1pvgm5 ca,bf /y qof a planet be R. Let the orbital period be T. What quantity is constant for all planets orbiting the Sun?+va5 feew my,/gbxqncs 1.p, *

  A planet is discovered to orbit around a styda xw/jks+aq27b im-r *i (y2ar 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 Su-2rx yji (a*qdkm 2wiya 7b/s+n, 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 *+09 (icap/dsit9eyse( pspr)e8 k wv"astronomical unit" (AU). An asteroid orbits the Sun(e */ aesp)98e+spcktdp v 9 iiwr(0ys in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. (l+s) mjof2jog.r:j d

  List the four fundamental 8.+pt;(zhnxao iz*dw forces in nature.

  An object moves with a constant speed of 30 m/s on a cir wd xh3d*k8lc2 f/wu ab::3 us k4vr9krknl4u1cular track of radius 150 m. What is the acceleration of the object?kxdw lfc:3w/491buvn83 k:d 2uuarl h ksr*4k

  The maximum speed around a level curve w m/(--bwwi nbis 30.0 km/h. What is the maximum speed around a curve with twice the radius? (As/w( -i -mwwbnbsume all other factors remain unchanged.)

  What is the centripetal acceleration ofzi6be 6wl599txr -ygt a point on the perimeter of a bicycle wheel of d6ry i6tg b5lzwt-xe99 iameter 70 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 8-xo2a3wi *b,kgsnwzb m7/ ajaxis. What is the centripetal acceleration 2w wnx*o3s7/j8baigam b-,kz?

  How many revolutions per minute m-*a(ty mn d9mkust a circular, rotating space station of radius 1000 m rotat(a mmy9n*-kdte to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mnv k/ bz9 i y arlvo,l485vm;bo8k,4d:vnsm :zass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is tkm9vdmv/:vb n,ok4 iba; l, sv485olry8: zznhe centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m strid1b8tivv7 f8,rv( jhw ng. 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 v1j 88(hb vrdf7vi,wt mass if the string is not to break?

  A stone, of mass m, ipa leix a i7p6+pv.dl*cd2i-3 s attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in .pxe2lipap6+ d3li7d a c-*i vthe 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 string and h)3kv:wf; +k w,;sto xojuc; lwhirled 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 atuwfhv t+ k,xs): j3ko;; olwc; this point is given by

  A jet plane flying 600 m/s experienc07nt(v(.o dwyra b .sden+t)pes an acceleration of 4g when pulling out of the dive. What is the radett s w(van. +0drp)n7 dy(bo.ius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the c4ez-p vi zj11qp)hb7uxb-; onenter of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with vu-nz;p)zeb1hi o4 qj1x-bp7 only one-half of his normal weight. How fast is he going?

  The maximum force a pilyir2/b 6gr a, xn:fce9ot can stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical div:bin6/r yfa2,xrceg 9e, can tolerate at a speed of 250 m/s?

  A car traveling 20 mf ox,gw76ax tj v;0pd5/s rounds an 80-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 each0d6pg vxf7;xjao w ,t5 road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20onu ov74ju-a ro-8e d-4i niu) m/s. The centripetiioae-47u) ooud j un4vn--8ral force 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 of oo xdapv98 :xl (h.r+m14 m/s. What must be the minimum coefficient of friction between the tires axa8odlv:r.xph 9+(o m nd the road for the car to make the turn?

  A car is moving with a constant sp zc3+x:. frwew/ f d5s*n hqu;j/nq8hjeed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minijj n rwq+hf xe;/z3wd58:qcn.fsh / *umum radius of the curve if the car is to stay on the road?

  What minimum banking angle is requi* g q5m(4x.fwpkzm- cxa9+dbhred for an Olympic bobsled to negotiate a 100-m(m9 p*.mdq4+x5czhxg a fbk-w radius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked atk5tnsos7h fs 7mqjqu :2n(0(i 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 aniog9gezg8 ntc1u-9ah4 (c z9y9yn mx0yny.t / angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i/ q8 xg++tmb7hj r9pay p;g9tts 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 uniformly 6ws,eh,q: v+tlmzgifv c2k1,in a horizontal circle of radic 6evw:s q,,tlif 2zh+mgv1k, us 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 accelerates at tizl1/+q2 rcba uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (obc/1l+ qrizt 2nly 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 consists of a prot;fc- 51b; f nfdp3 bxa6-v -yt scqmimszb/x7*on 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 gravitatii 79i-izc r114t.r q2kscdrxponal force on a 70-kg person standing on the Earth, due to the Moon? The mcir1 ixrtr ksc-7. dq 29i41pzass 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 bly qbt;/lswc,/f;6ebetween two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attracti/s, ct6l;;yb ewq /fblve force?

  For a spacecraft going from the Earzlho0*hhhn: 3g shlv e) , 813eg2vybuth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cah8lo0hz g:vu*s 3)2h1blhyng ,3ve e hncel?
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 Moonc/cgecx g 6/v 2h*by39jr (lzx 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 ,s 3(nnql)9og*nrseadld1 o) Earth equal to the radius of the Earth. What is hsn)9 e o lnd o(nr1dsa,g*)ql3er acceleration due to gravity?

  The radius of the Earth is R.h uhm *2zmt0nm-e cv;6 At what distance above the Earth's surface will the acceleration of gravivmh 6-emzth*0 2cum; nty be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface 2mgbaa*ove2*w2 rsh9 equal to 3 times the rao*eh2aavg w*s2bm9 r 2dius of Mars. 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, thn/8xk hhzgrj)0y6k:j2ekrr z2s g,v: e acceleration of gravity )2g :ey,/zksrkn2hzj6r08r :g kvhxj 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 the Earth. The Earth has radius r. If m:l)d n/ko+ykbgk r,. the object ob)m,yk rgkk /d.n+l: is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change when he g,/ ew uyri(2cx .tb.dooes from sea level to an altitude of 5000 m? (The mean radius of tht.,/i eobucw.drx2 y (e Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kl /8iwpb 01 qeci4o,b 4i.swu;6b gnc6ec,k ckg is at a point 3r above the Earth's surface. What is the satellitlciu,,1o ie.n c6 i06bc w4c wkpe/bkg 4;sqb8e's weight?

  A spherically symmetric planet has fourdh:-g bh: (qqk times the Earth's mass and twice its radius. If a jar of peanut butter wh d(- :qhbgq:keighs 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, Earth, and Sun all lie on the same line, wit x8 ubzn di*,q0po;hc9h the Earth z,dq obu*0 p;xi8cnh 9between the Moon and the 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 the Mooneythg/ 4rz1ws e-za 21.
(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 aboe3j. qd5yt5cq -s5*jus/x qc lut the Earth (i.e., it just skims the surface of the Earth). What is the speed of the jc3 u5.e- xq5sc5t/qjqlyds*satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circulauh9 xcul(0 dov1ou6 hi q,w54br orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution 1 0i6vc 4qu bh,ouoxuhlw59 d(around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km aboveju lmo;e4), ip the surface of the Earth. It is observed to have a period of 89 min. What is thil4;,pmou j )ee mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an or dt9mmn1 /tp6cbital 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 orbiihj6thv7wp, yke*v 7 *ts 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 orbital ra-o3v cjpez bdzh 0+1d1dius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to- de+p03jz1b1 hzvdc o complete an orbit?

  The planet Jupiter ilq 8/ lrhz*8- z9zmjjes $7.78 \times 10^{11} \; m$ 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 dg ux;, h/h7sithe average distance from Jupiter to h sdhi;x/g,7u the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)