Is it possible for an object moviy,a*id6l), 96 8rfzrhyh ph i1wbpp5ang with a constant speed to accelerate? Explai9wh zp,a rir6fbhy p6) pyda5i*8h 1l,n.

  Consider a particle moving with constant speed such that its acceleration o. swe:z5ge/ t6sm) +(ibc opzff constant magnitude is always perpendicular to its velocits6) im+g: eze (zb/.5fso twcpy.

  An object moves in a circular path at a const4 4wf j4vzcvk1 bmr.)nant speed. Compare the direction of the objnvf4v krzc 44w)1.mjbect's velocity and acceleration vectors.

  When an object experiences uniform circular motion,6u ao5)-f ga98vji zmf the direction of the acceleratiga6 -9jfzv)muo 85iafon is

  Consider a particle moving with constant speed such that its acceleration br:a;ie6,1 3fkxyj txof constant magnitude is always perpendicul:;3 e1a6,rtkyxxbifj ar to its velocity.

  What type of acceleration does an object moving 8iv t5n5wl;dllh;9r 5q iyr .zu87bv qwith constant speed in a circular pathhdzr9q t .r8i8yq lb5uv7;ln;wv5il5 experience?

  What force is needed to make an object move in a circle?1pb67z f i.c-h1 mxyu 42kaa hk8)rwsi h4ev;o

  When an object experiences uniform circular motion, the direction of the net for xisrl6;,g b/ibv1a+m ce/;abg, 6r+s1 bi lximv is

  A roller coaster car is on a track that forms a circular loop in the vertical7 l6wnhk o*qz 4;zo.e rezt6s5 plane. If the car is to just maintain contact with trackzs ew. 5z 76;lno hzer4tq6o*k 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 owl gca14q3tu 0 ckse5)n 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, wha 0e1 l4qksccwu )a35gtt is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc6uji jvv8l71pjx;mb-kw55owg 4q u(u until it is going straight up. Just as the plane is at i8uq7jwvpj g6 w1i ;-k 4louxv5 5mj(ubts 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 radiuhjqxv y4* g/eg04fj8qs $r$ 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 go2mouvzxm 6k lf 8l94j4.5koboes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second timj .4 ou9olz456xlkv82of kbmme, compared to the first time?

  A car goes around a curve of radiusalj8c8. zidu++ h,i3ull(. l 6alyepe 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 a (e,u.z8e l.3 6ahuiai+8 +cljlllpydround the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. v c/f 50bx v +/dlrvj )hp7:f3dwrq.lgIf the road is frictionless due to icep)l0w q5f/vxfbrlh/v 3j+ .crv7ddg : , 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 to

  Two horizontal curves on +tnqnyl)6m5it7 h(ev a 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 curve is v. What is the safe speed on the lq+6h7ntn t 5eyv) m(ilarger radius curve?

  The banking angle in a turn on the Olympic bobsled m.fxad .l df67track is not constant, but increases upward dfa.l m76fdx.from the horizontal. Coming around a 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 moving around a circular path to have both adu:* jqtb83dcentripetal and tangentialbad:3qj 8 *tdu acceleration?

  The gravitational force between two objects )g/*-lenbddl is proportional to

  The gravitational force between two objects is inversely proportiona*,b+c aib blv( ljz4 8x1efbx/l to

  Two objects attract each other gravitationally. If the distance baz rj wn/oiceqn3+; -0etween their centers is cut in half, the gr0caejiqn;w/ on + -z3ravitational force

  Two objects, with masses -/snm6pz a9rq h5 c3as$m_{1}$ 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 mass rm g1//aw+rkees $m_{1}$ 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 gravitp)r ty3zj t- 4vpm..a vw-j/jlation.

  Compared to its mass on the Earth, the mass of an object on the Moonh diyn.rsd9r)h ).lb62yu7 gc is

  The acceleration of gravity on the Moon is one-sixth what fw s;:v/1xss (8cyhc3yxl -nlit is on Earth. An object of mas-:y l xny1 s( s3csfvwhc/l8;xs
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket'se:c,rj h:q sc. weight

  A spaceship is traveling to the Moon. At what point is it bexb*37 lb g )n:ch+rf7)q1rlhflaacf(yond the pull of Earth's l*f +acg:f3 r17hcn7lbqf)(r a)hl xbgravity?

  Suppose a satellite were orbiting the Earth just abovev6/t *ohgmh s3hdrfk.z95a:v the surface. What is its centripetal acthkg6zv so h*fh:d9r.a/5m 3v celeration?

  A hypothetical planet has a mass of half that of the Earth anuyi/0 /kvm)y2 vo6oux d a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of 0v u)vk6oyou /i/xym2g, the acceleration due to gravity at the Earth?

  The acceleration of gravity(ac fy2o1w4 gs on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that off wy2s1oa4cg( the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the sv )nryuni9e6 k: zg1i7ame surface gravity, but planet B has twice the radius of pla z nn:7)19 6iveykgiurnet A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gradem ,1a p1aqg,w d9b5f1nq6wnvity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius of161a p5d,b 1wmwd naeqgqn9f, planet B?

  Consider a small satellite moving in a circular orbit (rad ad+4e- b -i-hii0bzfiius r) about a spherical planet (mass M). Which e-i fzi ie abi+d0--h4bxpression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotat/7nutu m/ ze upf.,l(ges in the same orbit. Cof,u zu(.7tmn/ /ulg epmpare the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Cl+ ;wb51ff j,7g p/vj/tsyl iqompare the reading on the scale to the person's tw,b sf5jipyf17l/v /lg q;tj +rue weight.

  Who was the first person to realize that the planetjye*0 s3n8ji x *f9yj-rsml3cs move in elliptical paths around t*f3 s s jl-e*ijmr9xj38y0ynche Sun?

  The speed of Halley's Comet, while traveling in its ellipticalcmz2 r 7+r2xg1 pwzzt: orbit around the Su z:zzcr2x +pmgt17w 2rn,

  Let the average orbital radius pv .ec7ftz-dkii - k(,p/c6l)z qjpr3of a planet be R. Let the orbital period be T. What quantity is constant for all.r fqcz-jd3/) kl ik,ietp6c-(7vpzp planets orbiting the Sun?

  A planet is discovered ty+ ulki6/;mvpb;wp ; af 89ozmo orbit around 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 revv;u/9 ;ap +p 6l8owbizkmf ;myolution 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 "astronomical , kct 1eet;+w4c0btja unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distkj,1tb cwe04tect+;a ance from the Sun?

State Kepler's laws.8ryxtvh6nf;9qj9gr-t ay)*2) x-x n+o zd hpr

  List the four fundamental forces a0qma kv-k h bjaq*dq90cs28bg87(gza 1 cxx.in nature.

  An object moves with a constant speed of 30ms,ew9qss 1z2bg r:0 x m/s on a circular track of radius 150 m. What is the acceleration of em 9xsz:s1 ,b2qw0grsthe object?

  The maximum speed around a level curve is 30.0 kktf: xujun(:84k; lmam/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.k; j48 kxuut:l(nafm:)

  What is the centripetal acceleration of a point on the perimeter of:w1ipqji kqg * u41;zf a bicycle wheel of diameter 70 cm when the bike is movikqiqj 11pw*f4g :zu i;ng 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ax2 as,3o3l+1bfc kiptk is. What is thek a2, ps 1iob+ft3k3lc centripetal acceleration?

  How many revolutions per minute must a circular, rotating space(21wvnun7fr tw 0,bqx station of radius 1000 m rotate to produce an xv1(0wuw2nr q,t7n bfartificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.lt).egjt bql+k:kk2c *.i h y35 km/h. What is the centripetal force ont3tg.lc kbh l 2*. kqj)yek+:i the motorcycle?

  A 0.50-kg mass is attached to the end of :+vbcvwc7aj g fo 7oa.tqg06- u;qj5wa 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 strina5vw .7c-u7 :oto qaq w bjfcv6gj0g;+g is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a veri6m 2s/qs l*+ hxjg3bbtical 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 axib h *s m3/qbj+6gl2st this point is given by

  A stone, of mass m, is attached to abuze /(.kcnbd5gl(,hd2 v1ca strong string and whirled in a vertical circle of radius r. At the exact bottom o( (,h1d.ul 5v ekbzgcdna2b /cf 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 jet plane flying 600 m/s experiences an acceleratio 37a/c+x *f7um l i-hqo0xgqssn of 4g when pulling out of the dive. What is the radh+- 0xci/ 7a7gs xu* mqlq3osfius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the center of the loop is a+gju9( cwg4paxbw88 beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-h ax88+wwjabc 9ggp4(ualf of his normal weight. How fast is he going?

  The maximum force a pilot can saiv( ia+5j1 pe(1 cvsktand is about seven 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 speed of (ac ai 51pve(j1vksi+250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve wi..1 cgbn +kox*gu90qae o (qolth the tires on the verge of slipping. How fast can this car round aexno.u1 g9 (+aclqkboo0* .q g second curve of radius 320 m? (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius 50 m with a speed oq+l4os y 6vcl :9btd;*zst0imu5romf0/0cl zf 20 m/s. The centripetal force provideby0scoms0lzuc*mtr+ l:td94 oz i5 q;6l0/f v d 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 1 ;almwsvem2 )f)/buy14 m/s. What must be the minimum coefficient of friction between the tires and the fmy lbw1s mv) 2a)e/u;road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The0 elw,gson+ 0c coefficient of friction between the tires and the road is 0.40 0 ,ogw+lnecs0. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking anglepvl 7q q,t3s,8oe 7hjkfif 97v is required for an Olympic bobsled to negotiate a 100-m radius turni,vpj eq8q377 ftvkh9sof,l7 at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on mbg7 nl6oiv5bew+o 2e:0jhm) a 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 ra )7x56 ukugqradius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedzvw *ag5j * rh(qveph/z8j:hjy9- 5rc 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 in a horizonta u9cvhws gv24p,f +dw8-ze1lll circle of radius 0.59dsgl+p-ch8 f uvzw1le vw24 ,00
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 v7 xwq7rv4sk1)s1c 7gl rtry;at a uniform rate to a speed ol7 ;y7s)xksv4r1v crqwg71r tf 45 m/s in 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 consists of a proton +2tqew-x y *lmof 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, d9y hs8vijapff24 a 7q;ue to the Moon? j sf;7af2qvi phy48a9 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 masses is Ft,zg 0x3+f3n:1ag2czore spa . If the masses are moved to half of their initial distance, what is the gravitational attractive fo:r nacz0o23 3fex t+z1g, aspgrce?

  For a spacecraft going from the Eartuyi)m3kd.cee(/ 6 btb j1r9(aexfum 6h toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cancxme.3bu f/6jiuc( b e r6d)te9a1y(mkel?
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 istu4:ifud0, r p $7.4 \times 10^{22} \; kg$ 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-walkln lv- ;c*mawn5kn02c" at a distance above the Earth equal to the radius of the Earth. Whatcnk lw nm-lan*520;vc is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface wimd6 f3-c;ye1* vy7ibu7j0wtqh an wol*5;nxc ll the acceleration of graviteic6;uan y7bhw1tdofnvm5 j 7 ;x-ywlq* c* 03y be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface e,f5tc wy, cud/qual to 3 times the radius of Mars y,f/w t,dc5cu. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 1400ej*/r-v ru rt; sfxf;10 km from some planet's center, the acceleration of gravity is e; fux-t 1r;* r/jfsvr$32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 N kjj4 d4* xzxx1j uy6 bls/56vton the surface of the Earth. The Earth has radius r. If the object is rax* dkujjjy l 4/t xsxz56v46b1ised 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 4y7,og:obd z;rj7vjlhe goes from sea level to an altitude of 5000 m? (The mrvo,4o7 7bz:ly; djgjean 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 above the E ffjgb 9x2,y6jarth's surface. What is tjyj b2ffgx96 ,he satellite's weight?

  A spherically symmetri.kr lhcx fe 3,;be;:vec 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 th:blvfr;cehe3 e,;k. xe Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Motz4t(b(jm qt9 on, Earth, and Sun all lie on the same line, with the Earth betwe(9jt(zm qtt b4en 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 transporgu cw kg q8*a6ti0m6,1+ bwhvco+7tm bted 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 Earth6c.osdp35w(2h cdwvq (i.e., it just skims the surface of the Earth). What is the speed of the sqwocc2dd v.(p 36swh5atellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orb.cv1 uk l9z /xa4oh-ffit about the Earth (i.e., it just skims the surface of the Earth). How long does it take thvl4o/ kafuzf1 x.9- co 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 k.1l:p .goc fspm above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean ra: 1lpo..gpcf sdius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has 7 fx-be-wxmofc*n j*xc28b+ z 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 orbits the planet with a radi l1dbz.q ;th jf5 b* f:xcjlsp5ro7h,-us 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 orbitz;yb 7zduzrk (xh9w6 a;gxo04al radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take 9huob ;rzg ;z60w(kxdx y z7a4moon B to complete an orbit?

  The planet Jupiter is /lpvm1dpj*e05p s0 f sve:,hz$7.78 \times 10^{11} \; m$ 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 ip i f kw/a6*s,ini6ci0s the average distance from Jupiter to the Sun? (The distance from the Earth tn,kic0i/swi p a6i*6f o the Sun is $1.5 \times 10^{11} \; m$.)