Is it possible for an object moving with a constant speed to accelerate? Explyc *gb abl-aapshmyd1 /;3 ,5dain.;dsapc l/y 1g-yhb*aa53 bd,m

  Consider a particle moving witk. 2q qo54zough constant speed such that its acceleration of constant magnitude is always perpendicula. zu5ooqg42k qr to its velocity.

  An object moves in a circular path at a constr5hd6vw d(r)want speed. Compare the direction oh6 wdrr( dw5)vf the object's velocity and acceleration vectors.

  When an object experiences uniform i nf :oglo8;,.q* )cadcr k7)j pnk7ddcircular motion, the direction of the accele ).;onrcd,fkik 7lgan:o8d pq djc7)*ration is

  Consider a particle movi mjsslnr j495;ng with constant speed such that its acceleration of constant magnitude is always perpendicular to imlssnj 49;rj5ts velocity.

  What type of acceleration does an object m- c)f 63zd dyw:ou5fbcoving with constant speed in a circular-ybw: z foud3dc)65 fc path experience?

  What force is needed to make an object move in a )c b37tu dblgr.-sae.circle?

  When an object experihhdl apoa(5n3 tb:q r( :.tnz)ences uniform circular motion, the direction of the net forcea(q:hrz3 t n:ntdha (p. bol)5 is

  A roller coaster car is on a track that forms a circular loop in the j7qch ,j zytn+.l1+yu1spnp 1vertical plane. If the car is to just maintain contc,s1+n1p+nltjh. p 1 uz7jqyyact 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 thcr3g85 iyd uti /;yw-: m,lashat 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, what is the minimum value for i u8t5 -,h;dacrsmi/ l:w3ygiyts speed at that point?

  A pilot executes a vertical dive then followsc zjby8h x8 8hs7zb6c) a semi-circular arc until it is going straight up. Just as the plane is8js7y b68 )zxczbh h8c 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 0c*a1,kfy: bak o. m io,bpc9mradius $r$ 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. The5fbe/ -ug.85 gocv1(sstljus n it goes around the same curve at half ./e1s 8bucvjt5 fgou -lgss 5(of the 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 it goes ar8nm;jmbl/ i9 bd 5zp(t tnc*i4ound a curve of radius 2r at dzjbcmi948 *5n l;i/tn(b mptspeed 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. vfx :8x1lb co2 If the road is frictionless due to ice, thec1bvl2o8xx : f 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 26ojqz u*,b gron 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 ugbr 6qo *zj2,speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled trf; +b,bih s mr mzp(,g2o 33gkzmx-2epack is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," thfbio hmm zm,3p-zgkps rx2+(eb;3 g,2en go lower coming out of the turn. Why do they do this?

  Is it possible for an object moving around a circulao;v o81msx9cr,,e hbcr path to have both centripetal and tangential accelec 9e;crs1m,bvox o8h,ration?

  The gravitational force between two objectrutv. qj, 0h 1sd )a3r-zzbt,cs is proportional to

  The gravitational force between two obn;omc-cya 5p 0jects is inversely proportional to

  Two objects attract each other gravitationally. If the dtj 71dqu e4r f10yq*c+4fitulistance between their centers 0fj741cqquf1y iert *4+ tul dis cut in half, the gravitational force

  Two objects, with mass4lp +io2qj xp,es $m_{1}$ 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 massesijsk;4 i4 /5 sl rrw/d+q;hobw $m_{1}$ 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 obmi3 ;i.nyax lj.n6)r f universal gravitation.

  Compared to its mass on the Earth, the mass of an obj/s tufg57:ryk ect on the Moon is

  The acceleration of gravity on f8v21 4xf;)wvife k fathe Moon is one-sixth what it is on Earth. An objec)4w ;f8vk ffixefa21vt 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 rockexbub:-ha 2 )oe t5;sjct's weight

  A spaceship is traveling to yel +4ur6lsj 8the Moon. At what point is it beyond the pull of Earth's gravity?+8l e rlsyuj64

  Suppose a satellite were orbiting the Earth just above the surface. What is 84lgsu.pk kz 3its centripetalk34.us kpl8zg acceleration?

  A hypothetical planet has a mass of half that of the . 6crvg;0bh ueEarth and a radius of twice that of the Earth. What is the accel6h.0;eb grv uceration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of govzeqcca 41ht 9:y( 3cravity on the Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. (v9qcz13et c coha4:y What is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has tw0,)qlsb3e + qpyzd1ds ice the radius of planet A. If pla1 dsqlpbdqe0 3y)s+z ,net A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice t:-*d 7bfb6) ku becezloj +zj3he mass of plan7lcjue*+3k feobb-j :d)z zb6et A. If planet A has radius r, what is the radius of planet B?

  Consider a small satellite mov/yy nfb *a98dr3y vmc8ing in a circular orbit (radius r) about a spherical planet (mass M)nyyydcm9rv / *af838b. Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and *zy l-r0+afqt rotates in the same orbit. Compare the two say- 0 f*qtl+rzatellite's speeds.

  A person is standing on a scale in an elevatov(*2dnozy le 7 4r,s.xrb-bc vr accelerating downward. Compare the reading on the scale to the person's true -r 4vrv 7ol*dbeznc2s y.b(x,weight.

  Who was the first person to c-bp wk c3n1g*l4nhs: f-z;-wbzvk1;pkb l5m realize that the planets move in elliptical paths around thesh bf34bppgv; nbkzn5 1w - -lkw czl:-1kc;m* Sun?

  The speed of Halley's Comet, while traveling in its elliptical orbit ae u kmm772af1wround the Sunm 2 weu71fakm7,

  Let the average orbital radius of a planet be R. Let the s. v filye)*s6orbital period be T. What quantityvl s6.i*yfe) s is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, witagp/k 8ot*fj6 (uo;mc h 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 planet be*cjuag/; 6 (pmo8 fkto, compared to the Earth's orbital period?

  The average distance from the Earthn8k(pne ek,0k to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in ok,k k pne8ne0(ne-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.frl)w t.(lt 9b+:oa dp

  List the four fundamentaletfv)ki ftoi w8;x5i8)n84yf forces in nature.

  An object moves with a constant speed of 30 m/s on a circular track of radiunr7 4- 9tfjvjs9fr7vas 150 m. What is the acceleration of the obj-vr99f77na4jv rt j sfect?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum 74vv(gnmts6 h1vf,k ge7bx- nspeed around a curve with twice themk n (bg64-evt 1vvhn7gxf, s7 radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a poe0hp7rf)/j5 milm q1 iint on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 7/q5 0m pf)elim ijrh18.0 m/s?

  A point on a wheel r25 / )vwds 4v+ettbaucmetw*2otating at 5.00 rev/s is located 0.200 m from the axis. What itctu)2vt2dmseww e v /* 4+5abs the centripetal acceleration?

  How many revolutions pe/(4:zm*: aoh mto gwrcr minute must a circular, rotating space station of radius 1000 m rotate to produce an artift/*4mcz:rwa( hm: og oicial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 1*ktvrhyxl ( p b4k8v* 3xio(:g3.7 m radius turn at 96.5 km/h. What is the centripetal force on th8p ogkv:3 *kvhibx t*r(4(yl xe motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The 2ct2)fv2r 4nhyl bn.9.jmjzw system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 35.2)jfb2n ly vh.m9w4 znt2rc j0 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 vertc80wx3mk0 a6vn4iu ko:v0cot ical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's we6 0m4wvno0kv k co:a3tcux8i0ight. 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 ci9 -vtz6 uwrtk 7dmb;1ionj,h5 rcb19t dn -ovj6,5;mwuthzi r7kle 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 this point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pultfzx:j1; 8 +45eccmm fp kgqb7a8gz o5ling out of the k5c x+mgtb8f: cz1o5j7 azpmqf ;e48gdive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which the cente vkkprydmx sw +85(d:3lor31er of the loop is beneath him) of radius 3200 m. At (3e r xv o+5ykwd:13k lpr8smdthe 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 stand is about seven times his ubsh f /ey-1lfxm /z* /psboz9w))4kfjws;t.weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dpw/9y b s/kuf1).) m j z4*h/sstlzeobfwx- ;five, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve withrc7 )iu,ivlt v: 2x(yli(0xjs the tires on the(j2vr,u:s )x7y0iv cli(ilxt 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.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The ct:/; ro7l olpbg/+a:bic 5t rcentripetal force providedo7:cbbl /p+o;gar:irl/t5t c by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve a1tu9*s2zrn:(/e:kmkor -b pd mwg8cof radius 50 m at a speed of 14 m/s. What must be the minm 9:rpn(rbs8:z-duce wt/2ok k* ga1m imum coefficient of friction between the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level curve. The ht0i9hq nz do,q:;fa,+ rs8co coefficient of friction between the tires and the road is 0.40. What is the minim;tf0+qio,89h:d nca,hszq orum radius of the curve if the car is to stay on the road?

  What minimum banking anglgwg+n*x os 7e5e is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s g nes57g o+*xwwithout skidding? (Ignore friction.)

  A horizontal curve on a bo+ jan8xvytb oam7m+ h(w3 2vw:bsled 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 radius 100 m, banked at an o)4rxhbh)e wgqq/ hv:8z)8oaangle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked bo(hwgp 7w,cn6lvj5 - 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.p:(n,6n6u ifd5ex *vn9jtjhk jf o+ m uniformly in a horizontal circle of radi ,pn hdjn6 *x6f .ukvne59imjo(f:t+jus 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 az w/-cz ih4ys/ :fk62lshmsi 2rea, a race car accelerates at a uniform rate to a speed of 45 m/s in 15 s, 2k i2h4/ sy6/ci z mlfh-:sszwmoving 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 oi0tj0 sk4m-mk3dlwaa w.x.s f.i5 oj+f 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 st*ge0 w oj3q7dwi,m v:canding on the Earth, due to the Mod3oemij7 v* :, gcw0wqon? 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 F. If the masseh+-of6ixg giu5 upto ()hg99es are moved to half of their initial disfi(ug )5htu po+o6ghg9eix 9- tance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the etf) yp(;bj5p+m- s.rv2qf rk Sun, at what distance from the Earth will the gravitational forces due rfvfs. e p)y2(mbk+p5q;r j -tto the 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 ccb3t dziinznnum+h381m75 uqf ;a ;* 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 Earth equal tok px/jlz e/zkw(k3dzh+w.8 j+ the radius of the dk8w+x k/3phz k w.j lz/je(+zEarth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance abofo i h..td u3w8jm4e7nve the Earth's surface will the acceleration of gra.m.8 wjn t43o7u fdihevity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance abovcb 9 7/mom(in a v486krhlriu7fl(a9ee its surface equal to 3 times the radius of Mars. The acceleration of gravity of the sat94 ifur 8avin6bk9l (oeac7l/ (mhrm7ellite, as compared to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's q/9lni(e3soj q-i 2odcenter, the acceleration of gravity i qo(iid 93qo jl/2sne-s $32 \; m/s^2$. What is the acceleration of gravity at a point 28000 km from the planet's center?

  An object weighs 432 Ns rhd2:g8w pir nn4 dh+fjbx:8i+kr(; on the surface of the Earth. The Earth has radius r. If the object is raised to a height ofh : r:(wpf+dnis+xbij82gk8nd 4hrr ; 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person chaeldqi* vsv q886+bfj-nge when he goes from sea level to an altitude of 5000 m? (The mean raqi flbv+ 8q s8-de*j6vdius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a poiv5k;z z+uq0tk nt 3r above the Earth's surface. What is the+z;zk 50k vqtu satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice 1lafi:kb1o )b its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the surface f1blbi:1k) aoof this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, wil- krg2b cem5+th the Earth between the Moon and the Sun. The Moon has a lb2rmk5g +c-e 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 transportt,+j 2arvikh67h y;c06f hxco ed 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 Earth (i.e., it just skims th7ag m5y as pavn;),,rwz8yl2ae surface of the Earpwm7 8a)rn,y,yg;5a laszv2ath). What is the speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit ab nhcjf)l 5 chsaups/np+z:2+ /out the Earth (i.e., it just skims the surface of the Earth). How long does it take to make one revolution around the Ea/c ns azhlfhu5n) +2+/pcp:sj rth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface 8gi:8vi l yq7474fxqmu: aj0qgx dsf(of the Earth. It is obsm u7v7ygf8 04xfg (d: aqqxj8:iisq4lerved 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 a. hso+-ov0iu 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 oo7nm(r6kg2 * c hj*)g het7xxg m0;xomf Jupiter 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 orbital rad iybn.ti. h 8 -j;iu9dwvz21abius r, and moon B has orbital radius 4r. Moo jiyiw .div- bhna.zu91bt;8 2n A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter isfiwzj78 n)- 2vwg+otc0hh5eq- /tom p $7.78 \times 10^{11} \; m$ 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 t4 zmf-)co(y jihe Sun once. What is the average distance from Jupiter to the Sun? (T(icmfjz4 o-)yhe distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)