Is it possible for an object moving with a constant speed to accelerate? Exb *z()qcotg 8uake5+dplain g*t(co+ z k5q8dbaeu).

  Consider a particle moving with consfx: my)r73re ntant speed such that its acceleration of constant magnituderx 7er3:)my nf is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Comp p*qian*bu0y ui 0c)n nahu4/(y3ibn,are the direction of the object's velocity and accelerati) nny0pb/*naq30 hu n uaub*i,4(iciyon vectors.

  When an object experiy-m j+ucvpzk t05 l5l b:- 6yqzj;ahh6ences uniform circular motion, the direction of the acceleration byam5:j+lpc-5l60q ; zzykh 6uvj -htis

  Consider a particle moving with constant speed such that its acceleration o99eigx 4steg 2bli8le-0b w2mf constant magnit29b9gwx i tebls 4 ei8l-ge20mude is always perpendicular to its velocity.

  What type of acceleration does an ob oz8p6p9t4g*qrw f+flknv6w *ject moving with constant speed in a circular pathq6*vno8ww f+p*tp rk 6lzf4g9 experience?

  What force is needed to make an object move c* k 3;l2pwp0yiwn0s lin a circle?

  When an object experien+.o(nyfyj/ y yces uniform circular motion, the direction of the net force fy(yy/+oj ny. is

  A roller coaster car is on a trac)nc fdb6tu/2idj+ oc:i :(fj uk 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 isfdicu +f /::d2ijjuo)c (tbn6 the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (raf7h+ )lc3eynqd z5xry lxi./ (dius = r) in the vertical plane. If the car is to just maintain contact with the track aqy357. cxf +z)/ ldrlin xyhe(t the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a seno8rptfb + yg57zvn,7il 9 ds-mi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forr97+8s ib 5zgvton7 py-d,nlfce 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 radi)2kvy(;iofm (5/ p2dc-dfvmaril 9wlus $r$ 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. Thv qkxt0ku;i /k5t lu(8en 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 cuu8i0xk;(t/ktvq u5k l rve for the second time, compared to the first time?

  A car goes around a curve of rad.zb* 9q*mq exlius r at a constant speed v. Then it goes around a curve ofx9* b*e lmzqq. radius 2r 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 radius r with speed v. If the roz;2+p k-jggviuq/tp1/, qcjd ad 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 magn,pz/k2j+qg1jug -c/qpvit d;itude to

  Two horizontal curves on a bobsled run are banked at the same angle, but onfqscp 4 lgn(-i crh)qk8-gb 38e has twice the radius of the othlcp8g-f8nk) qc br-h ig4( 3sqer. 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 larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant, bu4tcq nq:y x0tpy ,*pr:t increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "clim p rtq:p4*,y ytn0c:xqb 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 woo2 8(xks r:s)xbm0qnu;k *p have both centripetal a:xks)pmw n8ok 2xb* sqor(;u0nd tangential acceleration?

  The gravitational force between two objects is proportional tk njoo*t/2g y(eephblu88 d2 3o

  The gravitational force between two objects is inversely proportional v2m7l he-6d7tafacx/: qf ih 4to

  Two objects attract each other gravitationally. If the distl*f q4ys5i* j:yep ,zjance between their centers is cut in hqj5l s4ezy,yji *fp:*alf, the gravitational force

  Two objects, with masse4an zu:a::o kms $m_{1}$ 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 massesu288xg* .u aj2yef bymcql09 c $m_{1}$ 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 grgp qb:g ( )xily,a(d0wavitation.

  Compared to its mass on the Earth, thw22a x oyalzrl tfc337*n5z,s e mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is ljbwi -ap:w i4/7 3mwdon Earth. An object of m- djp:mw/i wl7w3ib4a ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocdz*irj y1m b)o v+v2,dket's weight

  A spaceship is traveling to the Moon. At what point is i wlnr6cz1:+oxt beyond the pull of Earth's g6 cor +z1xlnw:ravity?

  Suppose a satellite were orbiting the Earth juk nyl() -,3ms augez8qst above the surface. What is its centripetal acceleration?,u(ml3-y 8 )eagnkqsz

  A hypothetical planet has a mass of half that of the E6gnl/ yq:xdu: arth and a radius of twice that of the Earth. What is the accele:g6:/ luy dnxqration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Mo-fjkxk mdoysdv ,bxh1c902 2+on is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the E1+s2 mcx2- o09xjkb yhf,ddkv arth. What is the Moon's mass compared to the Earth's?

  Two planets have the sam2scnxe n3;;xgs t zc ;onu+s-0e surface gravity, but planet B has twice the radius of planet A. If planet A has mass m, what nsxs z u30en 2t+s;;x;gnc-ocis the mass of planet B?

  Two planets have the same surface grav/nmn kje(c/-yity, but planet B has twice the mass of planet A. If planet A/ (k mcen/j-ny has radius r, what is the radius of planet B?

  Consider a small satellite moviqfa.n+vl, 77nfslspj 9ap8:h mk 1 ry5) rhb9wng in a circular orbit (radius r) about a spherical planet (mass M). Which expression gives tpr+f,9 jh 1m7 8.9lfnabws nyp57lq )vhkr:ashis satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and 9,9nqfik -ds5c ;ptln rotates in the same orbit. Compafnl,n59q cik ds; 9t-pre the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Compare t2hyfqawx ,3*tle6t t5he readit,qah ftlw6x3te 2*y 5ng on the scale to the person's true weight.

  Who was the first person to realize that the planets movyv3e,0l28jp rkbb2 c)rh bc5 ue in elliptical paths arblvrkb3b cyecr 8u252h pj, )0ound the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit arounl3b2nnarv rs,g + ;6bhd the Sun,+hgnr63bn ;ars,l b 2v

  Let the average orbital radius of a planet be R. Let the old(v y +(p4vlsrbital period be T. What quantity is constant for all planets orbiting the S lvs4yd vp+(l(un?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with thh60ll mmh 70s;bvu6rye same orbital d ;6 l07rmy6l0v mhsuhbiameter 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 period?

  The average distance from the Earth to the Sun is defined as one "astrozw/pg6k055j7wzv7i v c e+k umnomical unit" (AU). An asteroid orbits thekjczvwwv07i7zkm ep6 ug5 5/+ Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.q*b93c0p zn /aiurad4

  List the four fundamental for2 0a humy+m6xgces in nature.

  An object moves with a consta n)tdikr -y0u*nt speed of 30 m/s on a circular track of radius 150 m. What is the acceleratiou*- 0 dnykitr)n of the object?

  The maximum speed around a level curve is 30.0 km/h. 9q 8f;*.erb rr-bmcmg,1rteh What is the maximum speed around a curve wit;mr qeg8.trb,e cf*h1rr9 bm- h twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a7ap udq7n;5 lz bicycle wheel of diameter 70 cm whel 7pd5a;uq7z nn the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locawfq h b 5)cd(:m00h4o hlh vtqa+-kwv,ted 0.200 m from the axis. Whathaqc d- v w q+)hbh(0 hotm:4kv5fw0,l is the centripetal acceleration?

  How many revolutions per minute must a circular, rotatiy+e9a 0 rqf l3xunj6m+ng space station of radius 10030f9e6+ jul+mxqnra y0 m rotate to produce an artificial 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 d v/weg: zuqz n+:h;r-96.5 km/h. What is the centripetaldzvuh qe: r+zg-;/w:n force on the motorcycle?

  A 0.50-kg mass is attached to the enfk*ys)vcgv1 le,bf0 ,d of a 1.0-m string. The system is whirled ikbycg ef* s,f,1l)0vvn 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 not to break?

  A stone, of mass m, is attac f1gbeco,4v83*jwo dwvz ry*o- -ul 3nhed to a strong string and whirled in a vertical circle of radius r. At the exact top of the pathnwv3jbdl* c*8-oo4ey w, f 1zo 3gr-uv 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 attach hc-kc 7p2c0ghed 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 thhgpc7 c c2k-0his point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out ob.i k,kjdd4)h )1n:wqi:d dlff the dive. What is the radius of curvature of the loop in which thkh)wd .n:1 4b,djdii k:l)qf de plane is flying?

  A pilot makes an outside vert sjnf7 rq;)fo.g:-u twnf.6opical loop (in which the center of the loop is beneath him) of raq.fpwtgu j) fs; -6n7o: fnor.dius 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 going?

  The maximum force a pilot can stt uxpl x+6ny(vw/ b,7cand is about seven times his weight. What is the mini/xw(c n6bx7 +pu ,vltymum radius of curvature that a jet plane'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 hvczt :z3 ahw0;cvdpqe,4r c02orizontal 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 2ah ztrw30:vcc0,z e v4p;dqctires and each road surface.)

  A car is negotiating a flcq jbc3 viw9*8at curve of radius 50 m with a speed of 20 m/s. The centripetal forc *3w9ivcqcb8 je 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 14 m/s. What mdt+/lm)of 0m 3z5vx kkust be the minimum coefficient of friction between the tires and the road for the car to make the turx5ok m/mvklf td03)+ zn?

  A car is moving with a constant speed v around 2bisfb+z,ce5 ,v p 8jia level curve. The coefficient of friction between the tires andb5 v,+ 2cfzp,sbj 8eii the road is 0.40. What is the minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle gm- (z;u nlk+x*f -uxhis required for an Olympic bobsled to negotiate a 100-m rafm (- +*l;xuxghku-nz dius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked a(:2ux2edz4 m-y)jx u ro /;tpyrgo6t gt 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;;v yvfs*o.i6/, ifrz ,qjtb htk mu64 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 0;e)obtm nn2f$45^{\circ}$. 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 hor/ ujn,c0 fnq9kp84wjf uvuh- bo q);.bizontal circle of radius 0.5 /u)p0ku jfc,h9n.wu;4-vfq bjn o q8b00
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 a uniforyt 8ni(a ;dc9em 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 blan 8(et9 c;aidynks)
(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;j ux5l41ny6 awjq. em 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 o3m0 azw3a1hf/kzyps .n the Earth, due to the Moon? The mass of the Mo3mfsh 0 p.a/z zy31awkon 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 ip slm9n3 xaj2: -/xsbis F. If the masses are moved to half of their initial distance, what is the gravitational attractive forca-ns2 jml pi9x/3x s:be?

  For a spacecraft going from the Earth toward the Sun, at w.a q)w uuam;y7hat distance from the Earth will the gravitational forces due to the Sun and the Eawy 7)ua.uq;marth 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 s3yvz l+*wr r7 d6sfn2:zn do1is $7.4 \times 10^{22} \; kg$ 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 distalb fj b25e:)sxni0 pub:o7q6cnce above the Earth equal to the radius of the Earth. Whacnqpjo6:72 b:ixbu05)b fle st is her acceleration due to gravity?

  The radius of the Earth is R.+ru+;2lihra.lfz-0i egf v3xx f9j6 h At what distance above the Earth's surface will the accelerati ii69 je 0uxar2h;llf3 .+-+xvgfzhfron of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 thautt;7w:1q n+z4eefvdazj :; -i9 oeimes the radius of Marst:uaz a:94;izet en efv;q-+j17hwdo . 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 plyjl,zzz+vukf- d . qg*kw2y ;ub))z 7banet's center, the acceleration of gravity is g .y kyz b f-zu+l*)bk2w,zv)q;zd7ju$32 \; m/s^2$. 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.dr)aj,w3 5og6b gq58,f waeor If the object is raised to a height of 3r above the Earth's surface, wr go w6rdga,w35j,)5b 8aeo qfhat is its weight?

  By how many newtons does the weight of a 100-kg person change when he gciz7 m k1kdji,rn 43ow0fol44oes from sea level to an altitude of 5000 m? (The mean radius of tm,0r ko wj14kfziod3l7cn4 4ihe Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r.t gkd8 r vef kz63+)u7velob;* A satellite of mass 100 kg is at a point 3r above the Earth'vrvde*oe;6z3 ul7k8+ g) bkft s surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its +fdggh 7sven;+( :akyradius. If a jar of peanut butter weighs 12 N on the surface of the Earthg es+ vand7 :+(;gfkyh, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the nh;w9 .it2p(yq io6slsame line, with the Earth between the Moon and the Sun. The Moon hay9ph6 (2wqi;nil o.sts 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 ttdcjs2t3hkx ;9 m y1,kbiub; 6o 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 orbit0rv- -qeka (jn7ebu t0 about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The meanjk--e(q7nb0rav te 0 u radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it juu9 834uguk+mced7abg st skims the surface of the Earth). How long does it take to make one revolution aro9k37 ugm 8 uegubdca+4und 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 sgmw;llw t,sx.f7-p30u-y q 5 q sb2lrxvf5t2yurface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The meaq-xf lpsmt r;.x30yl-2q7vw 55swltub 2,gfyn radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diametq1r7xn- 5 ro aanvrzhsod 1m8*24vb- ker 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 d2 l77r ztaz(pwith 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 m*g .45hnr2ky g )bdp+rx a:jgorbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to comg g*an+b :gkyxrm52p4r) .jdhplete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is 3z(xf. + * gcpcfidb-b$7.78 \times 10^{11} \; m$ 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 thead+m* qi+f)ut average dismtdfq+*a )+ui tance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)