Is it possible for an object moving with a constant speed to acce4kz,4ukihn q*lerate? Explai4i4uknk,h qz* n.

  Consider a particle moving with constant speed such that its acceleratio-;xo 4pdx4gf s1r+mbd n of constant magnitude is always perpenomp g; 4d1sxrdfb +4x-dicular to its velocity.

  An object moves in az z a t8yc5urpdq)xhk+:)9 -id circular path at a constant speed. Compare the direction of the object's velocity and accele9z+kci)8 5 -qrtd y)uxpd:a zhration vectors.

  When an object experiez/ plpkh5bpd: j2h9 /ww* +hi2hvys:d nces uniform circular motion, the direction of the acceleration is j/hh w2:ikp9:wl*zs/hhy2+5dvp bd p

  Consider a particle st/m -)wt9db20ewrmpmoving with constant speed such that its acceleration of constant magnitude is alwayp t09d2e/b-) mmtrw wss perpendicular to its velocity.

  What type of acceleration does an object moving with constant spim lfv 7-j0zm*y;-; txclr,y ueed in a circular path e- *7yzjvm t ulrf0x;;-yc,iml xperience?

  What force is needed to make an object move in aj6;jir xy ;(dk5f+imr0ot 4ff circle?

  When an object experiences unif. jstqmx u331j7vgq+ vorm circular motion, the direction of the net forcsg qv3.utjx1 j73mv+ qe is

  A roller coaster car fzb.bvo7o 7hfob84 r:is on a track that forms a circular loop in the vertical plane. If the car ishobv.7 7b b8:o ff4zor 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 hq* yby5 yo)5rm8n7laon 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, ol5)aryy8hm*nb7 q5y what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular 7ohv yyoux3lllhh)(f i a2rcwx:zl6,u .-/b /arc until it is going straillrhuza7 f,()i3.obl vhw-y lhuc:o/6x2y/ x ght up. Just as the 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 ray44x5, raq gxedius $r$ 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 con(gto0qy 3c) ovk rujta45 lq0*stant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes arountj*cu4r35a0g qkotq y0)vl (od the curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a consa+qdq+ nejquec5 /26ltant 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 around the second curve,aqdq/ e2+lc+ 6qun e5j compared to the first?

  A car of mass m goes around a banked curve of:bm.; 7o fn jpc-y4mjz radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the hor b4cjo;jzn:yfm m -p.7izontal 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 at the same ang7g lvyi,(7f s2 s3kfy7.stik rle, but one has twice the radius of the other. The safe speed (no friction needed to stay on the run) for the smaller radius curvekyfyfig,(77svk2 7ir 3ss tl. is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on thtoow r9w)x0 +,f6ytpve Olympic bobsled track is not constant, but increases upward from the horizontal. Comin9 vxp+,otr )oyww 6t0fg 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 centpc tolk5 0xn+r5.ds o9ripetal and tangential accelxs 09p5o. +n tr5okdlceration?

  The gravitational force between two objects ise*(xi 7 t0cbbee1le a 9du9a/e proportional to

  The gravitational force between twx7c r/hc q ptu 4do(gl346guj7o objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their9g:, q:wc*zck )fr4e hr3piib1 :tpma centers is cut 1: kp*a3 z)ref :gqicbwm4 :,i h9rctpin half, the gravitational force

  Two objects, with masi dv+/qoto .i2,raw,xf e:j 1rses $m_{1}$ 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(o baxdo;fsu4p . cb2/(h zk9xes $m_{1}$ 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 gravitay;fd*f dd2 tf.tion.

  Compared to its mass on the Earth, the mass of an object on*a,l / telytd0tz/har1 ii0n / the Moon is

  The acceleration of gravity on the Moon is one-sixth what i*: :hblnut)dl rag)j1t is on Earth. An object of mubn)gdr*:)lhta l:1 j ass
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 weid)mg5/ zz9vwppec.r( ght

  A spaceship is trave y(8+mp:at boqling to the Moon. At what point is it beyond the pull of Earth's graviyobm tp qa(:+8ty?

  Suppose a satellite were orbiting the Earth just above the surface. Whatd0+qw5n xh xm1 is its centripetal accex0w51+mdq xh nleration?

  A hypothetical planet has a mass of half that of the Earth and a radius of ter6.qf oq5 k ;w6ac2xiwice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the ox qaw2;ic6r e5q. kf6acceleration due to gravity at the Earth?

  The acceleration of gravity on .ygw:f uep-u) b2:z.t6zn ,m1auff dqthe Moon is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What mu.::)fdbfu6p uq,efy2a1-gnz .w z t is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twijm5p,., +-ghpg g iai1t8/lm36g gegcv(klnm ce the radius of planet A. If planet A has mass m, what is the lc5mphmkgil.g( e3p,8 1j/agvnigm + gt6g -,mass of planet B?

  Two planets have the same surf88 wyfq :a:xx5-5pv+qteay0gl u b: deace gravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius ox5-p :qd:au0e:b +yetaq 8y58gfx vwl f planet B?

  Consider a small satellite moving in a circular orbit (radius reztqjel / +k)6 l,yw;2gz:oro) about a spherical planet 62j lterw/:,;oez q )k ygl+zo(mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same b sek65uwf9 7sv1jcm :orbit. Compare the two satellite's speedsm 5sjeu19ksv: f6 cbw7.

  A person is standing on a scale in an elefdg-9m;xjfc o 19lck14njz +w vator accelerating downward. Compare the reac+x1kdjnfw9c l;- of4zg9j m1ding on the scale to the person's true weight.

  Who was the first person to realize that the planets m)xp6vaj87xsm c lkmq /h7bfgnifoxa- +p04,) ove in elliptical paths around the Sun?akp fqix)/6)xc vs-4 7fmamj+b gp7oxhl n80,

  The speed of Halley's Comet, while traveling atd7kea.b5:k in its elliptical orbit around the S de a7.kbkt:5aun,

  Let the average orbital radius of a planet be R. Let the orbitahilm5 *g:-3hof snla/l period be T. What quantity is constant for all planetsgfiohash l 3ln5/:-*m orbiting the Sun?

  A planet is discovered to orbit ac6- ah aecft-,round 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, whaht- ac6-c,fe at will the period of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance f b9 k0hrspv+g(rom the Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is thes (k+r9vg0pbh asteroid's average distance from the Sun?

State Kepler's laws.iv (x lqt4z;.y

  List the four fundamental forces in natureyusb a8* xpxo7:cylm5s,,0 aj.

  An object moves with 15ds:z*f neez a constant speed of 30 m/s on a circular track of radius 150 m. zf1*e5n :sdz e What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 . /)di( nfcud7z9jcvf km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain un(j ddnc9f7i u)v f./czchanged.)

  What is the centripetal accejli6g2 jfq8l9 leration of a point on the perimeter of a bicycle wheel of diameter 70 cm j69lfjiqgl2 8when the bike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s isn3t9(0kene, qx gca3gv+a e:w located 0.200 m from the axis. What isnaw:kq, 0ge ceg t93n(e+a3 xv the centripetal acceleration?

  How many revolutions per minute mus vlu*(7 ie.qset a circular, rotating space station of radius 1000 m rotate to produce an artificiallu(eev*. si q7 gravity of $9.80 \; m/s^2$?

  A motorcycle has a masot1wukgk0j p)),(hslavu99 ms of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centrip)wa01ghlums9 u) ,tpj(9 vko ketal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system8e1m ps n7/g/fsm8wqs is whirled in a horizontal circular path. If the maximum tension that the sfss mgs /8e/w 8q1np7mtring 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, iomyqn9; 9; mmts attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weighmtmnm;q ;oy9 9t. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirs5gpzu, r2w*:mt:mj;tp(tr v led in a vertical circle of radius r. At the evr r5ms 2p:w(p,t:g* u m;zttjxact 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 experieb d, 0lcjz 50v1xozvo/l*rv0bnces an acceleration of 4g when pulling out of the 0zob0b1 ,v/ z50r*d vlovcljx dive. What is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in which thaz 7b.7wkiw/ imx8q 5ee center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his bi/mak7 8ie7wq. 5xzwseat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is ab/ 5c0hyd*lpprout seven times his weight. What is thec y*l5d0rpp/h minimum 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 radmve/inr n*0z 3ius 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 coef30n* mzvne/i rficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve ohz2n6pm l9u g8 )s2vzjf radius 50 m with a speed of 20 m/s. The centripetal force provided by frictio8 hjug2zvpm9n l 6zs)2n is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flt5pnc 7 j4st1r6y sj2xwkk+i)at curve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of friction betwjk7 2tstrj)+1kwn4 ip65y xs ceen the tires and the road for the car to make the turn?

  A car is moving with a constant speed v around a level )kq i:w q4mrb3bh9 b c3zdq0u6pi(z3 rcurve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve i :3)49r3i3irkb qwb(qp0mdu z cq6 zhbf the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate a,.c-gdsyixe ,.a3 +o klqb6er 100-m radius turn at 35 m/s without skik,.q y+ d.elrigc6e-,3as oxb dding? (Ignore friction.)

  A horizontal curve on a bobsled ru*ofjgts5 o.g7n 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 anir t;(rbk hb h-*6b/trg9- lkmgle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banjp0flwho,5;ifmoq ph :bc 8 pp;ds- qj-0o8.tked 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 u1 tgvl+j0q a)p;(btf yniformly in a horizontal circle of radius 0.q b ptv+;f) 0gtjly(a1500
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 thx;3(pycziqb, f r0c0kv fao2 8e 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 a32f0 y cc,oq;pz08brxik( f vm. (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 prot4dmgck x10ao/on 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 gravitationa)816 k(m pbfaz,pw5 die s)+ v0xssodol force on a 70-kg person standing on the Earth, due to the Mo(wz) svp)d+f,8k6m5x ops d01aeobsion? 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. Ifnevh2j(lh n748kx9jj(c a* re the masses are moved to jhxeh9*nc( 8(4nrkave 2l 7jjhalf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, atv-bv 89q(- x: xbixdtw)7gxls what distance from the Earth will the gravitational forces due to the Sutb-xv x9vs -xw8bd( xq7)ilg :n 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 Mooniyvgn- m*3ew*z v6d 6a 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 5c ku:.bb h 0p1+ytkm ,ee.khmfor a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her accekk u yhtmbb+ ,5m.k1e 0ce:h.pleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will x ht hul,y6fn2)sj:5ethe acceleration of lhe)n x6:,ty2jfu 5sh gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equaljs:36aou. xq4 /i 2g)wzw3+wuvjw g sd to 3 times the u :24wugx6 vzw/dg3s + owsi3j )q.awjradius of Mars. 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 planet's center, the acnkxm/,(nd:g j celeration of gravity igk,(d /nmn: xjs $32 \; m/s^2$. 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. agxp-au ;o; :az.xe, yd)) r4hbwx)igIf the object is rbhgi zauy,xo .)dar)g 4;)ap xwe; x-:aised 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 he gojri u:-(clkr-+v0 nj ces from sea level to an altitude of 5000 m? (The m0-nc+kur (ij -j:lcr vean 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 th1 t21if z. u42v hko6omdav5mue Earth's surface. Whdut vk5vm26f2aimzo 4 o1h1u. at is the satellite's weight?

  A spherically symmetric planet has four times the Eartxad;eh 5,:y, yvoao)i h's mass and twice its radius. If a jar of peanut butter weighs 12 N on t;:,)hy5a oxy,iadvo ehe surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, w ekx)3xvqvczg4 8um-okp7 js 21d z-7tith the Earth between the Moon and the Sun. The M)kxek cgp71tzvj qm-d3 u47ovx8-z2 soon 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,)e lnj*-0e2tfwz qwd5cp.lg 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 circular orbit about the Ea8f4 +eo aw 6n-7.znr9 p kjml+:knezvyrth (i.e., it just skims the surface of the -elk 8nof + zv9:6 ej4akm+yp. 7znrnwEarth). 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 about the Earth (i.e., it just skims- /4vfzruby h1 the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius o/z1hbryv4f u -f the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km khenikq, x/3 t4r2 yb(ew( dqhda: )g1above the surface of the Earth. It is observed kxkhwd /(ianr2e 3, q( qtbh4 :yg1)deto 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 orbital b f// l(45 rrbqlnuls- /i5kjydiameter 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 plau9tm v3kv ,i+dnet 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 d-vml/l,ii-qw/dp :klv 4(pz circular orbits. Moon A has orbital radius r, and moon B has orbitp, ilpw-( 4/z-divm v dq/ll:kal radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter ibjsps rj417h 90 gxe8hz/0ms is $7.78 \times 10^{11} \; m$ 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 osc pdrp ;s35/a-pus l2nce. What is the average distance from Jupiter to a;u5l3d-s/ssrp 2pp cthe Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)