Is it possible for an object movinh;:t7jh mx-lry6hfy 2g with a constant speed to accelerate? Explain2yj-h:xh7y6; lrhmft .

  Consider a particle moving with constant speed such that its accelera o2 2 j7t5 6/d2iucdbxhlxj9option of constant p2xx2/u6 boh97 tdjo 2i l5jcdmagnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. Compare the diregfx +rov5-7yq- t0vk pction of the ob-5 pv 0t+k-vforq7g yxject's velocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction ofx29 oy*fxrz.s )ak2bf the acceleration r.yf af9o2kxb)x 2s*zis

  Consider a particle moving with constant speed such that its acceleration of )/ b,25-xscvtuq;errk s+ vrhu2 yxj, constant magnitude is always perpendicular to its veloc,sx xh rvbeu)j5+krqtrsy/ v22cu;,-ity.

  What type of acceleration does an object moving with constant sper7u+6g5 oedh yn4ofr 229sg cjed in a circular p orh9 7s4gg56denyc rj2 u+of2ath experience?

  What force is needed to make an objecto0 2b wlhk9o ca0xzwz2w*qm hu++rg): move in a circle?

  When an object experzy f7+/ vj;p.11bc y:l vbqgudis:di8iences uniform circular motion, the direction of the net force il+ y:8vub :;icij/1gbypfsz1 7. dvdqs

  A roller coaster car;fsdbh bc0vb9a6 ni; * is on a track 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, what6ba f0*b s9;bdn ;cvih is the minimum value for its centripetal acceleration at this point?

  A roller coaster car (mass pkui/2m6) 4x( pc*bnp y;dqae = M) is on 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 lo; cpxpyibm2/6p4nu*ka (deq)op, what is the minimum value for its speed at that point?

  A pilot executes a vo0ho kc/3j.cb ertical dive then follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forc0 jokc. hc3bo/e 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 w+7z4,sai7 s6ta y lrrradius $r$ 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. Then it goes )( q7xqiq+syb:pqv2yaround the same curve at half of the original speed. What is the centripetal for 2p (b +yxviqq7qyq:s)ce 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 ;,rtg/of, ,cl cjv8i zit goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it g,c ijz c,8v gtl/,o;froes around the second curve, compared to the first?

  A car of mass m goes around a banked curve of radiuo 8+oy h 8:-u0idcsk*jvmko. us r with speed v. If the road is frictionlesuskum:*ico88d v jo.y0 ok+h -s 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 are24m- ju7 nzondul;e6 c 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 smam;zc euu4 -djln7 on62ller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle inq .*cyexgp- acez53,r4 aoym: a turn on the Olympic bobsled track is not constant, but increases upward from the horizon-p.amze cry,o34g: y xcaeq5*tal. Coming 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 /+ ;,o-po czaqxs8aeag3dp/v around a circular path to have both centripetal an+cz,;3aopap/o/ e-q 8xvagdsd tangential acceleration?

  The gravitational force between two objects is proportionz 2.z ss8eq0(dq7shpy al to

  The gravitational force between two objects is inje x*wlb 5c9+dsa5 b:px6fv4oversely proportional to

  Two objects attract each other gravitationally.mwexk p y,d7i88.a-hl If the distance between their centers is cut in half, the gravitational f-87,ewkdx.8pi ha ylm orce

  Two objects, with masses 325pu40m4hijkwi 2zqgt f; hx$m_{1}$ 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 massea.0b+seyh)pd cpt-t*we8aziw6 re . / s $m_{1}$ 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 wi/)9qh, va j2yujo .ouniversal gravitation.

  Compared to its mass on the Earth, the mass of an objectl ob,8)hurus0.r *- :zdbrhao on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. An o kfmq3ak4,c c2bjec,a4f3qkkc m2ct 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 weigh3is*fr dux5x q34h1v4lnpn /xt

  A spaceship is travelg r;vv9;3 :uy*argaq oing to the Moon. At what point is it beyond the pull of Eart v9ruoqg;a*g3r:y v;ah's gravity?

  Suppose a satellite were orbiting the Earth just above tj3):d2ykj fz;tx:wrphe surface. What is its centripetal accelerax;wfkj:rzpdty : 2)3jtion?

  A hypothetical planet has a mass of half that of the Earth and a radius of twic mz ev6qmj(2nd::q3nje that of the Earth. What is the acceleration due to gravity on the planet in terms qnj: q26en3 jz dmm:v(of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. Tu(od mfbyc-p ;o,i5p 2he radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth' pm ;u5pfy2c(do -o,bis?

  Two planets have the same surface gravity, but planet B has twice the rknqe7 cphtgcg2 :;xzd/ 7jz +r1py o18adius of planet A. If planet A has mass m, what is the q 2dro :gj7cp/yzegxz+knp7 1 c1;ht8 mass of planet B?

  Two planets have the as2scj/jtb +, same surface gravity, but planet B has twice the mass of planet A. If planet A has jst jacs/b2,+ radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular 2qw* .dm3x:kak5 mwcgorbit (radius r) about a spherical planet (mass M). Which expression gives this satell5 c *k3:.qgdwamwkxm 2ite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the same8f4*) a*tjxy7h dxv t-b8yx fj orbit. Compare the two satellite's spe8f fbtjyjx )xyt 7h*4- 8ad*vxeds.

  A person is standing on a scale in an elevator accelerating downward. ntwgh*a8838qdgu *dxj ;j:ubCompare the readiu3djg8utb ;qn 8ajh*8:w*d gxng on the scale to the person's true weight.

  Who was the first person to realize that the planet*u:evfu+8/o br lyqc8 s move in elliptical paths ar8f/+q o 8urlec:* yuvbound the Sun?

  The speed of Halley's Comet, while traveling in its ellipti 6s6u,lwmi u7fcal orbit around the mu si7 uwl,f66Sun,

  Let the average orbital radius of a planet 3knm7ph u3h6 uo0c2yfbe R. Let the orbital period be T. What quantity is constant for all planets orbiting the S3f 6uh3hmp2yn uko c70un?

  A planet is discovered to orbit around a star in the galaxy Andromeda, withfr36x;i oz:kc the same orbital diameter as the Earth around our Sun. If that s6 fxzr;i3okc:tar 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 dw6 ..j-yifkqa efined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from q a6i.fj. -wkythe Sun?

State Kepler's laws.9o7w gocsnt)t+q)wfmw. 4t h0

  List the four fundamental 823. dmrax91a/ vcsskr d9 ubsforces in nature.

  An object moves with a constant speed of 30 m/s on a59jiq cy m9yrs 4kf9b5lvejg2d7+m :g circular track of radius 150 m. What is the acceleration of the ob 954jdj:lyi7 f egs2+5myg9k 9mbvrqcject?

  The maximum speed around a level+ a:i *1 ,s c5n:jw/szjt.0zf6qinmawa ok n5x curve is 30.0 km/h. What is the maximum speed around a curve with tw:n5+*f /s wwaxman :.1ikct5ij 6szqjz oan0,ice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a qr.e7mwb- rz5 bicycle wheel of diameter 70 cm when the bike is movizqe-b 7 5rmw.rng 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.20 rgpz n2kh;y1g+*4dsuncz k 9(0 m from the axis. What is the centrid;41uk9knsg(h*+z g2cny pr zpetal acceleration?

  How many revolutions pya mpvlhz+2h0zqg/ ) -er minute must a circular, rotating space station of radius 1000 m rotate to produce an artificial gh2z0l-yhpqzm ) g+v/a ravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.5 ;mny5p*4p,k z:kc(cjba w t+gkmpyk(,+ pmat:4*;cwg j cb znk5/h. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the er5.rs+ma 4:-jvgva fuyd3 hc +nd of a 1.0-m string. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 35mr y .4-5v:a +3dvhgusjcar+f 0 N. What is the maximum speed of the mass if the string is not to break?

  A stone, of mass m, is attached to rtf rz11vy* 7bq6ojx.a+scg-a strong string and whirled in a vertical circle of radius r. At the eg+b117sxrtzj-ov.ry c*f a q6 xact 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 a y:)be(yk 5b hpp t+c0ge:gtn8ttached to a strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in the strinc5t ebptk:npb(eh y g+80y:)gg 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 4gmfmwvo 91*;sis k5 ,ur when pulling out of the dive. What is the radius of curvature of the loop in which i* ,;1o9 5wfsrvs mkmuthe plane is flying?

  A pilot makes an outside vertic rh0xow/ 2xa1v3y-ouial loop (in which 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 w xy-ovwho1ux02ia3 r/ith only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is about seven times his weight. What is t:yy1+e.c k xfthe minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at ay:1kxcf. +tey speed of 250 m/s?

  A car traveling 20 m/s round, e nt8:0fvmcik8l sx9s an 80-m radius horizontal curve with the tires on k:le8 vt0in9sfc ,8xmthe 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.nmj1+7.uifshmy jl .8 a9c4yz The centri9 u.jf.iaj1 4+ ycmmzl7 hs8ynpetal force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cmq y*f ;n63*frq2jy-umz 1ya eurve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of fricti-q* *njmez63qy m;2 fauyyf1ron 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 curveejaf8m 8+/ks5ub f w6y. The coefficient of friction between the tires and the road is 0.40. What is the minbf k8w/ejsy amu58f6+imum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Olympic bobsled to negotiate6 -pv*sau k/th7 (lltv3fiw5f a 100-m radius turn at 35 m/s without /v3tu7hiasf(5 6kl*f -tl wpv skidding? (Ignore friction.)

  A horizontal curve on a bobsled run j wt*l 4w.5masitd h-)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 oy sez;z1vi 73af radius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m qfe snk rf *1,vewp/ 0mm.87ibis 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)mqr5bbome/w0 v)bl. horizontal circlebbo5)b . l/m0me) wvrq of radius 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 area, a race car accelerater*zdp)xa ss7m yeb;4j f7e, 2rs 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 numericea* yb7p; ,fz4e 7rsjdsxrm)2 al 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 consist2vzq pa2 (f+a1vyp ,;xs /d2xtz4 uiubs of 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 ppfn d1r7fyh/o 1y +-kxerson standing on the Earth, due to the Moon? The mass of then1o fy 1h+xpydrkf/-7 Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractine5dr d:/)x kw5r(d ye6 q:pdqve force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational akn6rq eqddd: 5ewdp/)x5 y:r(ttractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from t*iga*i v6nn0 :kyowo+ he Earth will the gravitational forces due toino k0i *6*oa:n+gwv y 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 im: c wchnghh3xn xbe,-, :.o;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 ah,66q/f4e m6ly3cvnx a+keeq distance above the Earth equal to the radius of th3a e,m6qhek 4cy+eq/fv6lx6ne Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will ta, f5 zgggt7s5he acceleration ts5fz7 5ga, ggof gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surfa4 ek))j(x sgprce equal to 3 times the radius of Mars. The acceleration of j)kr4 e xg)p(sgravity 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 acceleration of grap(;pxs ) baun3m6-.-0ux6wbmacy kr qvityw.xp0)k xsbbr-36m(q a6yn u-apu; c m 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 the surface of the Earth. The Earth has (i*xbk3t df;qbh* g) l.7tzqbradius r. If t 3qbxfzk 7d b.bt;g**(hl iqt)he object is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight o*iq*fh.()yxml,v3 x n (bbnqa*1 nedof a 100-kg person change when he goes from sea level to an altitude of 5000 mdx nx1ofn i( *,3av (my* )q*lnebqhb.? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A 7fnz v0n( xd)fwish5) satellite of mass 100 kg is at a point 3r above the Eav f(ish7w dz0nn5))xfrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass and twice its 0d.5q y u.rep(tk .sujradius. If a jar of peanut butter weite .u k0yusq(..5rdp jghs 12 N on the surface of the Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun al iol e;ua/s,r3l lie on the same line, with the Earth between the Moon and the Sun. The Moon has ar;auei, l3/so 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 tof2e8,co8 uy pq 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 7yzr -c6bcc1 borbit about the Earth (i.e., it just skims the surface of the Ea-cc1c7 y6rzb brth). 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 or2iv: p2 dez o4qaro,f7bit about the Earth (i.e., it just skims the surface of the Earth). How lp:i q7,zr24d2f o vaeoong 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 circula6ojc 85h vvm7ar orbit 230 km above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of 5o8vc6av mhj7 the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupiter, has an orbital diameter o2cmyr: odm);f4s lk wo/9 oc+kf $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the sq cj0/ujg66*bqw(q y5ziq5q 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 planettwb 9h9+hk vj/ *ns9yu in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days kjys+nvhh u99*/ w9 btto complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter issnaa9(3 ;qw ln $7.78 \times 10^{11} \; m$ 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 Jupiterjc7om(8n(v9l 0a vrvi 12 years to orbit the Sun once. What is the average dvm(j0c98liv nr7( av oistance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)