Is it possible for an object moving wih572n5cor8ebuwh ,k gth a constant speed to accelerate? Explai2n hc ,hbuer875kow5 gn.

  Consider a particle moving with constant speed such that its accek pw7j5um tsmi 590;wnleration of consta nkw i9;sm55 wp0t7mjunt magnitude is always perpendicular to its velocity.

  An object moves in a circular path at.vz/l -f8izbq* k ,dqc a constant speed. Compare the direction of the object's vev*i/ c8,qzz .fdlkqb -locity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of thf 0/b5vddy7o y)hqn91:i0z sxo5ouon e accelera o50xsuno/):vh yz 7bdo0nfi5 od19qytion is

  Consider a particle movingi1;1* xh x2 nrvree/lcy 5oo0x with constant speed such that its acceleration of constant magnitude is alwayxln 0o1cxr5ye*e2v1h oxr; i/s perpendicular to its velocity.

  What type of accelerjt)ib84imcpzz9o 20 mation does an object moving with constant speed in a circular path exp p4oi9zi08)cb2m mjz terience?

  What force is needed to make an object move in qj;a; 3s +9sn4gh:yr b) pflhdlp;m0sa circle?

  When an object experiences uniform circular motion, the directionsoy*z3 z;g u)g of the net forc3zg;yu g)zos*e is

  A roller coaster car is on a track that forms a circular loop in the verticalr(, e3y:pzq:zako sc / plane. If theqpz r,ce/k:(: a3sy zo car is to just maintain 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) is on a track that forms a circular loop (r6rvpm6, pjwu hr8v8t 0o)m )xvadius = r) in the vertical plane. vh8m0p 8r jumtvv6pw6)o),xr 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 that point?

  A pilot executes a vertical dive then follows a semi-cir37l8ov kn)px ecular arc until it is going straight up. Just as the plane is at its lowest poin n3x8v)loke7p 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 of radiuk*w* r4ru;ph eb y:kr qb-b 4h(g+/vyxs $r$ 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. 8n.jf3i/ vwc1k6sv jv Then it goes around the same curve at half of tnci/ vvv6j.13wkf j s8he 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 radius r at a constant speed v. Then 6raj , mkc+m6wit goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it gr m66wc mj,ak+oes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of r 1yfj.en p reu2kx).9l/y9jf radius r with speed v. If the road is frictikef/e .nx.2)fjul91pyy rr9j onless 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 to

  Two horizontal curves on a bobsled run are banked kuf /wm24-+j(ee rimgat the same angle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for j -imu4 gm (+ewref2/kthe smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a thak3opmu/ hl++) c8w murn on the Olympic bobsled track 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 the turn. Why d/wc )m+uohh3alk+8m p o they do this?

  Is it possible for an objt+vptnl 1/h y(ect moving around a circular path to have both centripetal tny/(tp 1 lvh+and tangential acceleration?

  The gravitational force between two objects is proportionvz2u.sfm 7wedj hfv18i,iif h)w*01 jal to

  The gravitational force between two objects i2puio:prus / 0dz4:lo)ml- hd98sgt cbw- m :os inversely proportional to

  Two objects attract el xupfi/ 2*k-zach other gravitationally. If the distance between their centers is cut in half, the uk*- 2xl /ifzpgravitational force

  Two objects, with maso9q02wsg d+t y. pfpu:p8lv,zses $m_{1}$ 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 masses w)ri r/ xotkr/wcv; (;$m_{1}$ 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 of3l pp qj0*hs8r 57q2o jal*daq universal gravitation.

  Compared to its mass on the Earth, the mass dq a4ptwn *3/nof an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth wha(fmjc2q qo-mgfj * :a g,4m-pat it is on Earth. An ob,o(*24af afmpmcmjg:qqgj--ject of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the rocket's wesh(v4gc k.or 8 bre:e n2wq5,e(alc(cight

  A spaceship is traveling toycqj +8mhjt.t35pr5 4ud pq 9k the Moon. At what point is it beyond the pull of Earthct 953jq 4rdmt. 8jph uy5+qpk's gravity?

  Suppose a satellite were orbiting the Earth 5 xy2s/l ,2wz5q nn2noan l4ruct(m(rjust above the surface. What is its cqmsl ,(5nzur2ncwxt2no(2/5r4n yl aentripetal acceleration?

  A hypothetical planet has) xvm/ozv9tbm v3s3nhvcca/ 4op,66m a mass of half that of the Earth and a radius of twice that of the Earth. What is the amc,vmx6tmop v 6)/bonzh 43c3vas v/ 9cceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on thsn5ukj+)(t4 guy vrt0e Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's)+ ust5n4(uvtr gk jy0?

  Two planets have the same surface gravity, but pla) c e7diyt.6)dsde8 xbnet B has twice the radius of planet A. If planet A has mass m, what is the mass of planet B?ddd7e)ey sb8 6 )icx.t

  Two planets have the same surface gravity, but planet B has twice the2. w+gv q-diij0 ;o -pyh7rfca mass of planet A. If planet A has radius r, what is the radius of plv gwh;-yqi72+jadf0 ico .pr-anet B?

  Consider a small satellite moving in a circular orbit (radi-6 o *we0ypmaxf n0* ac;ofk,qus r) about a spherical planet (mass M). Which expression gives this satellitew f y-0 ;am,x0ekfp6oncqoa* *'s orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the sam kg oa2j-fxu0/d 3foc9e orbit. Compare the two satellofg/09a3kc- 2jd f uoxite's speeds.

  A person is standing on a scale in an elevator acaif a, oex/g/+)uda4*geod r)celerating downward. Compare the reading on the scaoa*g// dfor4e)u adga+ )e ,ixle to the person's true weight.

  Who was the first person to realize that the planets move iq(o+oynka e8 1n elliptical paths ar8(k +o n1yqeaoound the Sun?

  The speed of Halley's1ej+au3 a( v(l)acf yx Comet, while traveling in its elliptical orbit around the Sun)a f+lyu 3(aavxecj( 1,

  Let the average orbital radiux: vnsqk t*(.a74 gepbs of a planet be R. Let the orbital period be T. What quantity is constant for all4 (*gxqa7t:nk e. pbvs planets orbiting the Sun?

  A planet is discovered to orbit around a star pn4vijdb0 9i5 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 revolution of that new plane 0np 4j5i9bdvit be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is defined as one "astronomica :( em:. aq7d8kydytgnl unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distancgytd ( .7e :kady:m8qne from the Sun?

State Kepler's laws.h xmh17ua7sl e8j/t kz/pvy25vk) gu/

  List the four fundamental forces inc)ihz;aa) ftc*83 jsg nature.

  An object moves with a constant speed of 30 m/s on a circular track of rbbk3*k(dlh 4j5sz y. sadius 150 m. What is the accelekylbszks d4 .*bh (35jration of the object?

  The maximum speed around a level curve is 30.0 km/h. What ish,aj(t c;0qwi( g5y vq the maximum speed around a curve wit0cia hvwg; 5t(q,jy(qh twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicyctw;qhz; *h43ko8 qhuk le wheel of dhw8qz 3uoh k4*kq ;;thiameter 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 axis. * .7knz oc qjkj08f4jwho 8a.sWhat is the centrkwak4 .8o . z*nj87jqos0fchjipetal acceleration?

  How many revolutions per minute must a cimo fwes147ei- rcular, rotating space station of radiuso1sife4-em w 7 1000 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 25k- 9bxhcz co-90 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centrc9cx -zhok -9bipetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system is whirlhnofa a p-ay9xi1)*/ ced in a horizontal circular path. If1 9)xh-fy nc*a /ioapa 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 attached to a strong string and whirled in a vertik a 0 kf7das:vd-+tqy9cal circldkf9sk0va ay+ :7dq- te 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 at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a vertical c+lt xsg*x)/na ircle of radius r. At the exact bottom sxt) axnl/*+ gof 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 experier.:hfc4pp, o+ c6xkqt- ,ukpmnces an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loop in which the plane is flyinptfp -4xpurc+ :k6,coqh k,m .g?

  A pilot makes an outside vertical loop (in whichtp,7.g +i gzbu 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 ft. 7,uzib+ggpast is he going?

  The maximum force a pilot can stand is about seven times his wel )(3lzrd:buxl( ge4jight. What is the minimum radius of curvature that a jet plane's pilxr(j3zllgle4(d u:) bot, 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 horizonn3 lwikngoz855+r,wy tal curve with the tires on the verge of slipping. How fast can this car round a second curve 8zkr+iwyn,o lwn5 53gof 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 speedrw x6rk8awrx 3melmtm;4ng39 3ebr )7 of 20 m/s. The centripetal force provided 3rgr4amrxb l3w ;3n)w9rmexm6k 7e8 tby friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve )n)g n yj5qgc9osbs z9h*.4umac3us4of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road 3b az.*sch5s9nq9 ymg) 4ucsjogn)4 ufor the car to make the turn?

  A car is moving with a constant speed v around a leve5aypay)p d* *kl curve. The coefficient of friction between the tires and the road is 0.40. What is the * adpyp) yak5*minimum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympicuji9k hq5.ja.ubktb: 1m)i 0yj/ q k(f bobsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ii:hq 1 yk.9mb)kfk.b(5/qt ui ajjju0gnore friction.)

  A horizontal curve on a bobsg6nxnvjl3 41 jled 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 i7ptnfoeip4 ( + rm68 a1gyl;rof radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is * c,9e2empuz+n;b cc ibanked 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 horizlhojxu i0 s):+ontal circle of radius 0.50sh+0)ljx i uo:0
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 uniforg8s6s5m yn0 znm rate to a speed of 45 m/s in 15 s, moving nn s6sy0gm8 5zon 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 of mas q j8ip-jyeh70s $1.67 \times 10^{-27} \; kg$ 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 h1 wpyw ;. * /9zz2hiuqm6hvudforce on a 70-kg person standing on the Earth, due to ;vu 9uz*w/hywqphzm6. 2di1 hthe 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 force betbbme-bae. s/6l2.8 p-zo89wuf movbkween two masses is F. If the masses are moved to half of their initipb2kvsu-m8 6l/9fw o.ee8bobaz -. mbal distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, atav wbb ,egtptg n49nd;fa( -,8 what distance from the Earth will the gravitational forces due to thgwg;an4pt bnf8vd,-e,t ab(9e 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 is xn b+r ,a2/e,uug8jzb$7.4 \times 10^{22} \; kg$ 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" atc*bh4oijzv 3. a distance above the Earth equal to the radius of the Earth. What is her acjvi.b4z 3c*ohceleration due to gravity?

  The radius of the Earth is R. At gq6mo/-c3v 92fvdgw owhat distance above the Earth's surface will the acceleration of gramqvfdo 2v/ oc-9g wg36vity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abola+v-cox, 0cgm g-1rxve its surface equal to 3 times the radius of Mars. The acceleration of gravity og,a 1lo+ cc r-gx0xvm-f 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 ceicho m1wtsyn34b/b1 qb d: 45rnter, the acceleration of gravity /n4m sh 54tdob: y13cbbqr1 iwis $32 \; m/s^2$. 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 rth w.n, qoah 5e((vw/s. If the object is rai(vhwo/qs(we,ah n. 5tsed 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 n3 *s122borh er3/kk +fbjs 0ivtn(gmchange when he goes from sea level to an altitude of 5000 m? (The mean radius of the Ears+(*13bb ivr2nfkt/ onj3 r0 seh2 gmkth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of maqum9-wux0c) p ss 100 kg is at a point 3r above the Earth's su0puqc)9-w xm urface. What is the satellite's weight?

  A spherically symmetric planet has four timevnvyh2 58 -uacs the Earth's mass and twice its radius. If a an8chv yu5-2v jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moonf9t tq;pe e8 8q /c74wiarrdg.(xsxb4, Earth, and Sun all lie on the same line, with the Earth between the Moon and the Sun. The s (xxedqc;r/4g7.ba rw fit948qe8 t pMoon 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 ,wk f b1uxx 17s.nvwk2is 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 low circp 57j k:oc7s1/csrifjular orbit about the Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radiuscp7ji15o: f/sr ksjc7 of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth0awzxnm*-0dsb *89 e vc mkja7hd5,ven+se o: (i.e., it just skims the surface of the Eare0c e7n a9s*bd:sjek5,o*8 dn0 xz v+ -wmhavmth). How long does 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+/w(tv ;nnq t 2 azkm,4)/0xl9yaltwlm xe9t j 230 km above the surface of the Earth. It is observed to have a period of 89 min. What ismwnj (02 k)tt+ 9 atx/w9/vmq , llx4lteanyz; 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 diameteiv 8; yqyh2dzzz8y:q*1 kng ;xr 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 np ;(v,j+p golu(lg7o orbits 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 o:lu, scp4bj1qg pxn,6 rbital radius 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 completebug clx,4s,n:16j qp p an orbit?

  The planet Jupiter is x(m:2h/u zayb5+;oiqqu:e us $7.78 \times 10^{11} \; m$ 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 ijp ,iv+2qjz e)s the average distance from Jupiter to the Sun?,ezjqi+ jp2)v (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)