Is it possible for an object movingab/-f 1exm* ep8 irh3e with a constant speed to accelerate? Explainmhe rf i*eb-a8x 1p3e/.

  Consider a particle moving with constant speed such that its acceleratio:7n8y xig if h:vcu:y.n of constant magnitude ish yvcn7if :yxi:g8u.: always perpendicular to its velocity.

  An object moves in a- jepayixw8g-;ho9 ,d o1tid/ circular path at a constant speed. Compare the direction of the- txd,8o dpw;-iia yo/ j9ehg1 object's velocity and acceleration vectors.

  When an object experiences uniform circu 0at*ix5z3we5a lsw--vqdwo 4lar motion, the direction of the acceleratied3xzoav* iw50swa4qlw- 5 t-on is

  Consider a particle moving wit :p/vby ch tq4c0yfz/4h constant speed such that its acceleration of constant magnitude is always perpendicular to its velocic4/c yq 0 vpht:b/f4yzty.

  What type of acceleration does an object moving with constant speed in a circulc10j4q-*jnzof hft qs4ch: 5aar pathq0* n44hfqth jzs co5: f1c-ja experience?

  What force is needed to make an object/iwf ac,nf:s3cja5 )y move in a circle?

  When an object experiences unifoc da8,zy5o- oj b/: ikcq,9tijrm circular motion, the direction of the net force i,oyd t98 cczj-o/k,:qabij 5is

  A roller coaster car i s xz:8awlb/,xs on a track that forms a circular loop in the vertical plane. If the car is to just mai8zs /x :xabw,lntain 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 td1)m8my* 1wb.pho e3lewy)iw hat forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the mbyw3p mw lhydi1*))8.wee1otop of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it zbaa 0+v.+ ux3yya4ph is going straight up. Just as ybvuh3a4. x z+ aap0+ythe 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 radius )wtdi; i/cj(d $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of rada3xw2x mhw c+9ius r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centrixh+2xwm9aw c 3petal 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 8b kiqeu7r.dxx n*x7( v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetalxxr7k7n(.qbudi*8 ex 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 va *iw3 ul pgfjjqit68+a.g2c(. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force oq g (gtl6u3a 8f ij2c+wipja*.n the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run ar0tc :.xsjh0 0 rpstib9e banked at the same angle, but one has twice the ra 9bhx 0s sr:ji00tp.tcdius 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 larger radius curve?

  The banking angle in a turn on the Olympic bobsled track is not constant,,te:( 0c c,emlbbxljp1p; dp) but increases upward from the horizontal. Coming around a turn, the bobsled team will ip0d;1mecx le bcb):l(pj, tp,ntentionally "climb the wall," then go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving arounrbu)1bydmcxg 3/7 w 9od a circular path to have both centripetal and tangential acceleration7cd 3yu1w gob)9x/ rmb?

  The gravitational force between two obj*rz , stn;iq(nay e8:rects is proportional to

  The gravitational force between two objects is inverseyh0 oq- ma:u5vly proportional to

  Two objects attract each other gravitationally. If the distance betwee56d0 ikqiu : sh 1wh+j/)sxlkfn their centers is cut in half, the gravitat5d0kksi +sjlq) 6/uh w:1fihxional force

  Two objects, with mask9hdxhyx4 hn gv-i+ srl9:9h.ses $m_{1}$ 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 ma dqhs6ql+rby-38q 9 casses $m_{1}$ 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 univers: ca1rxgk ff; bo1+.lfal gravitation.

  Compared to its mass on the Earth,b t q8/vz/lb1e the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it ir- -0nd1u/ w lfbpucw2nnox,os/ rn0 *s on Earth. An object o10rfc *2wo-wxo /nu/ 0rnnd ,us-nlbp f mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface, the royb3a1y6 k0g0ptmbz t4cket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the puhvmd,+e3s q r)ll of Eartvm+q) ,es dr3hh's gravity?

  Suppose a satellite were orbiting the Eart cvhqoq/u+z 95h just above the surface. What is its centripet 5oqv9/hq z+cual acceleration?

  A hypothetical planet has a mass of half that of the Earth and a radius kwh 49ri8)rscof twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the accelerw)crs8kh94 riation due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on zpbw(h ;:s; jsEarth. The rh sbs:z(p; ;wjadius of the Moon 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 plana jdmia-e u+i 0ee,())nu k2qy,x;nhss48 ppcet B has twice the radius of planet A. If planet A has mass m, what is the mass of8 h pees yca kjsinpa2d),q,)n-04;(+xiue um planet B?

  Two planets have the same surface gravity, but planet B has twice the mass of 2eva fyq.;p( qplanet A. If planet A has radius r, what is the rad q2p;f( .avqyeius of planet B?

  Consider a small satellite moving in a circular orbit (radirc qdug 0wzqn( ( l1/qs06mp;zus r) about a spherical planet (mass M). Which expressm ((/qpsw1rnqc 0qz6g0 zdlu;ion gives this satellite's orbital velocity?

  Satellite A has twice the mass of s,edk njxi(9j;1 +c(win p1dvcatellite B, and rotates in the same orbit. Cvi,;dn9jn jx1(cp(+wk i ed1c ompare the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating downward. Comparei- 2cx ,7n)ls8)oq0s mpiza bh the reading on the z2a, h 08nob-7isc) ximqsp )lscale to the person's true weight.

  Who was the first person to realize that the planets move in elliptical )gdkn n.;,.kj t9rg obczx1n6paths aroundn.x 6n9g;.z bkdcgnjk)1rt ,o the Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit arx3 ht6e4 hu)mmy4isgwm v h7+2ound the S4mh3iw m4h7h2xuvm)ys gte6+un,

  Let the average orbital radius of a planet be R. Let the orbitalc;xf(e n 0 wzgv8)h7*0:znzyf+bpl wx period be T. What quantity is constant for all planets orb (0 pcz*nv:nwh+fgb; xeyzwzf0x8 l7)iting the Sun?

  A planet is discovered to ore) yk6nu0kgy; bx0z 1ibit 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 re0n k0eg 1x6y )zybku;ivolution of that new planet be, compared to the Earth's orbital period?

  The average distance from thenqhm; a/vj 1bw.c5 ,s0dmjsh 7mpva-) Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-/;wch)m -s 5nshbamap 1mvqj,.v7d0 jthird of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.ec9ec f+vroriu7 ( i 96c:,afg

  List the four fundamental forces in nat(73whnfz0zs gure.

  An object moves with a constant speed of 30 m/s on a circuudd/d0*5 a* x)w j0ihvvc1vmz lar track of radius 150 m. What is the a d *vwid*j50v)vauxczm01 hd /cceleration of the object?

  The maximum speed around a level curve is 3 *zbo3 lt8wuhaj* b1f10.0 km/h. What is the maximum speed around a curve with twice the rad113 fauto8l*bwhj z*b ius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a bicy xl 25hh/x7-bwyo: olkcle wheel of diameter 70 cm when the bike is mwlx yhkx-/ bh2:l oo57oving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis2h- bwc: 0w,th*bomsk . What is the cm2ww0hc *st,bh-ob : kentripetal acceleration?

  How many revolutions per minute must a circuv gl; +tm*qc0 :f)hryzlar, rotating space station of radius 1000 m rotate to produce an artificial +tq0 )m gzvrh;fy c*l:gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radi(-:skq ubxr j+cd*:n cus turn at 96.5 km/h. Wha :n+crb-*s:(uxj kq dct is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The syr/( v zom+*kn (lj z8r/phutn5stem is whirled in 8 k5+(ln/rj pzvh zmuo*/tnr (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 attached to a strong k dfqmu(d*(9.xhbcb1te) g h2string and whirled in a vertical circle of radius r. At the exact top of the )d(bfhu 9dqh(t .gbce x2k*1mpath 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 vertic j o4w3/v1debval circle of radius r. At t v3b/w4 ovej1dhe exact bottom 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 jet plane flying 600 m/s experiences an acceleration of 4g when pullingits+*b cva1ev jo yp75th v:50 out of the dive. What is the radius of curvature of the loop in which the plane is flyte0 tcbv ah 5pj+v1yio5sv*:7ing?

  A pilot makes an outside vertical loop (in which the centerepbm h3 9a.p9k 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 fa.mpe9hb3 a9kpst is he going?

  The maximum force a pilot can stand is abou 2 x7:mxcn2 f0e9ot3tiwfb3aqnq+2g et seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a23a 2mx0t9w2tif cxf 3eqb:e+ngo7n q vertical dive, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an n)hv) 8pmr7geakvb9bnqa 6z/ 7b6v d680-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 surface 7ap/nbmhrvk6edvbbz76a)9 q86v g)n.)

  A car is negotiating a flat curve of radius 50 m w3q tdjoj7xsz(v8es7 h6w4f5pith a speed of 20 m/s. The centripetal force providve38js7 tqj56woph f7d4 x( zsed 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 am,9--e5bc im p*.iaz3 xl whsm at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires andi easphi-b95l3 wma -c ,mz*.x the road for the car to make the turn?

  A car is moving with a coniuf5*. o-mm4m *j mi x*xdw-onstant speed v around a level curve. The coefficient of friction between the tires ad*ox-u-im* m fm x5*jnw4moi.nd 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 is required for an Olympice +dnrosnhlg 1ox57h )(m8*js bobsled to negotiate a 100-m radius turn hs+*8es57 doo1 ngnhxr) (m ljat 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is banked atdizyut /i3n/-4 lmpr8 chzt;7 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 t we (6o)pl,arm, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m l4+qp/i7wrd4j:fdftr8(2xx yh f c4 sis 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 in a hor4/n ta )d6iqpbizontal circle of ra6aqn/p ibt)d4 dius 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 idw /9tthj/pbv/qu9 b+n the pit area, a 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 numttduj 9vbp qb/9 /+h/werical 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 kx/ i2ty jjjxv.9a06y 2yqis/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 on the Earth, due sw1qrps)x v8j)b6n fyyrur6 a-+7.wq to the Moon? The masss8qbv s)p-.+a wyn6)f jwr qrur1y6x7 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 id69 t8k 5 jarrr4vgq (w+gh5grs F. If the masses are m g46dhv5agr 8jr5(9t+wgrk qroved to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance mr8avhc 7 +to+b9et.4:kf nnkfrom the Earth will the gravitational forces due to the Sun anh4r8v:e.f tk+ a 7kcb+n9montd 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 iskmn- fyb4,a .pby6 dmz1e 0wl, $7.4 \times 10^{22} \; kg$ 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 p;j+:zj8isvg to the radius of the Earth. What is her acceleration due to gravityv;+8 gspizj:j?

  The radius of the Earth is R. At what distance ab)9jw1xf ez;,l yblz 4w(epux+z thh55ove the Earth's surface will the acceleration of 1 )+5; e5h jyueh xb(lwfw,zl4zz9pxtgravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal toa0w( ;r aoiv atd1z82k 3 times the radius of Mars. The acceleration of gravity of the sat2o0 tk;a (z1wd ariva8ellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some plgf)q3xwc uvm0 r6 44vfanet's center, the acceleration of gravity 3frmu qfvxc6) g44wv0 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 th;c5gnqka-0 gv fn-do;e surface of the Earth. The Earth has radius r. If the object is raised to ; 5gdn ;qk-acog nf-0va height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person c owhsos*)* ksgo/b4m. bz0zn1;.hq tchange when he goes from sea level to an altitude of 5000 m? (The me0 wt g oh1 b/*c 4)sbsmq;..k*ooznshzan 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 pv7f,b-n4/ lakyet e9 (tbn;jnx;5h sp1,v wx eoint 3r above the Ea1,7 f/;w,-vaelenthje4y bxb sk;(x5nt n9 pvrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times th7c*kh q 50;jgursai7 z ay8)eqe Earth's mass 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 r)yh 08i7a k; 5 j7sqa*czeqgusurface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the sam9rn /x6/i-sv dnzr+:ld a vxh0e line, with the Earth between the Moon and the Sun. The Moon hs/69+drdl 0nav -zhi rn/x: vxas 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 tra *xp5uvx sk,cd-u2 se5nsported 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 Earthr jm7:zdcua tu)*32ip (i.e., it just skims the surface of the Earth). What is the speed of tjuui7p)3 dr:mcazt *2 he satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Eap 2sxk ;oipx9hj8 1whxuy/ 5c(rth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius of the Earth is h58h2xc(x ki/wuyo;p 9sxp j 1$6.38 \times 10^{6} \; m$.)

  A satellite is in circularp5 l97i)0d2j ck4 /mmg7 w mudkxk/alg orbit 230 km above the surface of the Earth. It is observedk7c)m g au0i /jglxw 27dlmmd5 /pk94k to have a period of 89 min. What is 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 orbitabos) :p7r)w :3a(d .g werhmeil 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 pltnki(br a neu;o*f -e+a.slr,-(i2h aanet 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 radinwtw6v s-w2c0us r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How lo-2wvnc6ts0 ww ng does it take moon B to complete an orbit?

  The planet Jupiter is6a0;rnvfut q-dd(h dsq*8 m(n $7.78 \times 10^{11} \; m$ 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 the average yfyzp;ifig:;s +y0:cdistance from Jupiter to the fp zc i;y;:+igyf :0ysSun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)