Is it possible for an object moving with x(+ r-x3avgr c /j)ickutr-.z a constant speed to accelerate? Explai .tu)(r -ikg +axxr-j3vr/zc cn.

  Consider a particle moving with e:::8v pebr 1xxn2oktconstant speed such that its acceleration of constant magnitude is always perpendi: e:x8 xpo1br2:ntvke cular to its velocity.

  An object moves in a circular path at a constant speed. Compare the direction o mkri w (,rnx2, 7:s8fezjb)rjb.dd)kf the object's srz2( ejd.mjr7)bkx:f i8b,wr),k dnvelocity and acceleration vectors.

  When an object experiences uniform circular motion, the direction of the5+gesrm k (;cccay44j acceleration +gr4a (jc; cyse 4m5kcis

  Consider a particle moving with constant speed bk5p7 cw5reod czq *0j2up41s9irpt1such that its acceleration of constant magnitude is always perpendicular to* j0wzpok92 5ip1q7c srrc41p ubd e5t its velocity.

  What type of acceleration ebs x hwtfs )/5)yr- zgh2)vn;does an object moving with constant speed in a circular wyth/)nbsr x5vse2 )fh z;g)-path experience?

  What force is needed to make an object move i 3ahjm oi++an9n a circle?

  When an object experiences uniform circu e9(z(z 4vt3kahiocti.up d p617mlf6 lar motion, the direction of the net force ishp o1m6ei(v z3utpd.f z9k46l (7ti ca

  A roller coaster car is on a track that forms a circular ln koi;:9 iba4/kmhlm8oop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at thi 9nmk 4iba:8hk om;/lis point?

  A roller coaster car (mass = M) is on a track that forms a circ3 vxa94/xmepd v b.n3g*aypb*ular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the trace4*/ nbvpad gy*33mxapv.b9xk at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive th;l::y4n f kkynif 246dz dcw,ben follows a semi-circular arc until it is going straight up. Just as the plane is at its lowest point, the forc i,2ddf:zn;:lf 4bywn4 6ykkce 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 ral zj: a mj ug9xedy8 .cskav4ys4g923)dius $r$ at a constant speed $v$. What is the direction of the net force on the car?

  A car goes around a curve of ra3h0q9hd(kux i ;edbz4dius r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the cend ez;40hxk(3uh9 db qitripetal 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 spee fm27ridy;i(itb1n( gd 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 n if1bgy;2r(i itd( 7mthe second curve, compared to the first?

  A car of mass m goes around a bank9/zs+ *(jjhb ch5quy sed curve of radius r with speed v. If the road is frictionless due to ice, 59(sy+qzb u/h*c hjs jthe 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 bobsle9hhn(uyidz.)h p).lhp d 4au: d 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 puhhu. n 9pd 4)y(ad :.zilh)hradius 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 conyo b6(l-sz+zqi6m di 2stant, but increases upward from the horizontal. Coming around a turn,mzi-i6by 6z sl2q+d(o 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 l;6r syiuv ; ,q 6d4z/rkuu,ofcentripetal and tand6yiq ;6;f l uzuurv s,k4or/,gential acceleration?

  The gravitational force between two objects is prop *ofvq b,xz32bortional to

  The gravitational force between two objects is inversely proportjj(a*c 7)fexrpv 3m2l tun- l-d 0sa7yional to

  Two objects attract each other grav9yquuu55npa s7n 95t ywdvu.(itationally. If the distance between their centers is cut in half, the gravitatip95auud .vn7nytqu59s wu(5 yonal force

  Two objects, with masse7dqyw o,in80y16gm dzvc2/ fo s $m_{1}$ 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 masst66( vk bdm .gb7 /ok5cyiyt8hes $m_{1}$ 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 univ15* j0 lujvhahersal gravitation.

  Compared to its mass on thewx)wt s*sqpbb(0,k a2 Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Earthb6 wvupep9vg5s(+9h v. An object of mass(e5 6p9w+v9uhs vpg bv
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's sur5+8ijgz cfu rjj+3z6g face, the rocket's weight

  A spaceship is traveling to the Mv g+iy qu -d06 :dfjma5wjid((oon. At what point is it beyond the pull of Eafiaj+d -dyv(0 m:5( g6ijdwuqrth's gravity?

  Suppose a satellite were orbiting the Earth just above the surface. Wj: t9ib*,dbsphat is its centri: i,*bpbt sdj9petal acceleration?

  A hypothetical planet has a massj dt30y5yhu1w of half that of the Earth and a radius of twice that of the Earth. What i jyt531yd 0whus the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon is one-sixth what it is o - xihyu+s1++btq3ps3sr*: mxgcrd*vn Earth. The radius of the Moon is one-fourth that of the Earth. What is the My:u +bpm d1-3s c qxr+ivrg+3*th*xss oon's mass compared to the Earth's?

  Two planets have the same surfagifo1tiz:nde.+t r/j l 4c ju 1ck5,/rce gravity, but planet B has twice the radius of planet A. If planet A has mass mn z.fj:cir c/el1tj/15guitr +ko ,4d, what is the mass of planet B?

  Two planets have the same surface go*xzuts , .;q2ktcob : fbac+*ravity, but planet B has twice the mass of planet A. If planet A has radius r, what is the radius :tzbqfs.acct;ok2, uo+*x *b of planet B?

  Consider a small satellite moving e4a :zr7 bf0uein a circular orbit (radius r) about a spherical planet (mass M). Which expression give0: f ear4zeub7s this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates v ak99qz6nn6e in the same orbit. Compare the two satellite's speeds99z6ne 6nkavq.

  A person is standing on a scale in an elevator accel7 um-hv*x(uow ,c9 y46+ikz8u 5jm 0ubzkgxdwerating downward. Compare the reading on the scale to the person'80 u+z,(kdv65 m9muwzixoyw-u4 xbcu hjgk* 7 s true weight.

  Who was the first person to realize that the planets move in ellipto 9 yx ee4(6ax5sutnb72h jsp7ical paths around thn59bh jpsux74txs ye(o6 e a27e Sun?

  The speed of Halley's Comet, while traveling in its ellipticanj,qldpwhqh:8g6 qilbs - -,0l orbit around the S-nqpw:q,ih qhsl d-6l0 b8g j,un,

  Let the average orbi fm-;a4yf3zhy tal radius of a planet be R. Let the orbital period be T. What quantity is constant for all planffz yyma h43;-ets orbiting the Sun?

  A planet is discovered to orbitz x3)8xgcodku7* . xpc 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 3kozdcucxp ).*x7gx8of revolution of that new planet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Suc*;dxe jum6,ulolglybac) em; - e* n.yf04;q n is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average d ,d ecfymj*e*a60cl bl.;ol-;gqu 4me xnyu ;)istance from the Sun?

State Kepler's laws. 5ggmw1vu*xl(+h o i u,bnki+)

  List the four fundamental forces(p g p0 to3u/8qqfkbj) in nature.

  An object moves with a constant speed of 30 m/s on a circu6tsgqxr7ee2 i- qqwc/ hd/*b uxq+cq: 6xz)k *lar track of radius 150 667 i/qxczkxq*c*/qeg s)u -2xdwqth qber+:m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h. What hj5cwn 48* igjis the maximum speed around a curve with twice the radius? (Assume all othern84*jjhi w5gc factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a0t*g8n cc9 6 i:etbmhz2s8vsa bicycle wheel of diameter 70 cm when the bike is :in*zhtbag c9mv80 2st86cse moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is locatedy, 0maiqq;a0ccc gl s9r,r-6u 0.200 m from the axis. What is the centr 0-,au0qcs,gmcc9 q ra6rly; iipetal acceleration?

  How many revolutions per minute o szcis+*9 k:*ac.hlhmust a circular, rotating space station of radius 1000 m rotaa +chhkczs9s il:o*. *te to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn or9tm7hk(o chh 7:j9fat 96.5 km/h. :7oh9t9com(j hfh 7 rk What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m string. The system i3pn1:ob:l g 0w2b)s txn5y yuns whirled in a horizontal circular path. If the maximum tension that the string can wb nsuw)y0y32:o:bnn1 lgt5xpithstand 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 anceyewu ws3wq484fi/z5-m b 2h d 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 weighw83f hm4 qs/e 4-zb2i5eycwuwt. The stone's speed at this point is given by

  A stone, of mass m, is attached to a strong string and whi)0-ytqloabn 9q dql32rled in a vertical circle 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 bt q n32d9)ol aqby-0lqy

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulliup.n+x2bdu n3f s.jxew-i5 y jspc-/,ng out of the dive. What is the radius.b3-u+isd jy-p cx/ jen25.xs,n fwpu of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertic/s*zk j/clzb6v6f x e d1z1nn:d)r8p hal loop (in which the center of the loop is beneath him) of radius 3200 m. At t pd/jhz n1c6l:v* bex/n r)zfz61sk8 dhe 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 weight. What isjl8e,ekn +/.1k;hz ked l,n co the minimum radius of curvature that a,l/l+jo, c h keke;1nzekd.n8 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 h;gp8 qx3xt: * dh2 fjayaus3; pwgns43:-uab 80-m radius horizontal curve with the tires on the verge of slipping. Hp8bxgt2dx;puj-;g3nqahsy3 4f* h: ws:u a a3ow 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 2:(zq;dh s8tfq4hb ;az0 m/s. The centripetal force provided by frict sahqq(zb;fz;h td4:8ion is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 5* d/ik9ezwq4p0 m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the p/ i4e qk9w*zdroad for the car to make the turn?

  A car is moving with a constant speed v around a lei5t d*,/yg ud2d*bbtkvel curve. The coefficient of frg yudb/2*5i tddbk*, tiction between the tires and 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 Olympic bolcu u(,x71wwfbsled to negotiate a 100-m radius turn at 35 m/s without skidding? (Ignore friu w1f c(xul,7wction.)

  A horizontal curve on a bobsled run is banked ap6,hoxy6mu+cf pfr; : t 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) im9ax+ je6bv bj-4an, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m i1u dm wgq,)x7d7hkbo.s 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 horizontal 5 q0 r)u0adkosos* bger69:yccircle ofde r ucor0g0 osbs9a )56k*y:q 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 ac)+jw/nhmd kqhjs 11a 5celerates 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 numerical value in the m jq/+nhj1a)whk 5ds1 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 p jicor)1e-3hp roton 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 gravitationalck-c*ahh(;r q force on a 70-kg person standing on the Earth, due to the Moon? The (h h;ra*kqc-c 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 force0e9 q-;.2l ac7 hdunnti red3v between two masses is F. If the masses are moved to half of their initial distance, w2n3;i0etdv7 dru -hc9elq. anhat is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from t;en; e6g r87bow phoxo0y:tu:)fx vw /he Earth w0: :o xoex ey)pb;6n7gtuorwh; v/fw 8ill the gravitational forces due to 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 e57tsujot ,:fik9 :,hy7 zwo qis $7.4 \times 10^{22} \; kg$ 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" a8u+(7l,b4;g dzkc s yi0rfigk t a distance above the Earth equal to the radius of the Earth. What is her accelerationfz +i7 d,yc( 8li;g4 g0kuskbr due to gravity?

  The radius of the Ear)wn9ap5gefv-d 9:wu -k u9tq0v00efpq6 h ohhth is R. At what distance above the Earth's surface will the acceleration 9wfkv50qw )0-96hq-t9h uud: ofp0p ang veehof gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at 57slnsf, sh9 jp*z fa)q-gl2wa distance above its surface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the sjz s,n* 9)l5lq pswgff7 sh2-aurface of Mars, is

  At a distance of 14000 km from some planet's center, the accel5/f) t)2: ;n(rtktzvuvish4tdtsa, deration of gravitydt id;rk hnv5v( 2tz)/4)tsu:satf,t 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 radius r.ylzknlp o 9p;jiq7+dw ,d1q7 )iy: (xac6x u;e If the object is raised to a height of 3r az q)iioxppcllx,ky+7qj;u7w d:(6;a ned1 y9bove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 104mm- 7 4psrup/a zq suyi*v48i0-kg person change when he goes from sea level to u4 up7arpmmy*iz svq/is -4 48an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg 3p4nzgwb3qtd1 2/ x4yf:z w lsis at a point 3r above the Earth's surface.gb31xzqyf/: dtw s n44wzl2p3 What is the satellite's weight?

  A spherically symmetric planet has four times the Earth's mass nzy. 3) hvcce;lmh z/ /6fi u,rel27rzg8dgy+ 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;ihr 2.+ cy3) zny f,zg8l/eg czu6h/ev7dmrl the surface of this planet?

  During a lunar eclipser,fo n5u-du v/, the Moon, Earth, and Sun all lie on the same line, with the Earth between the ,/5udu-r fnovMoon and the Sun. The Moon 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 tru*7wsb5(hr h aansported 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., iti233e gs+boar just skims the surface or+sga3 be23iof the Earth). 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.eq pk8/w8gb;z gy3e;du zn5c a6., it just skims the surface of the Earth). How long does it take to make d36 e;qw8b/y5z8 znucp a;kggone revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 k.uya1z309,y a tr24dt 8qgj fsck+ bxnm above the surface of the Earth. It is observed to have a period of 89 min. What is the mass of the Earth? (The mean radiusy+4bzd ta3k,r txsjq 2g a81nu09.cfy of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Jupokfnv2u5xy(:l 8dh7 l iter, has an 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 of Jupiter orbits the planet with a r)a-x ymc1q:rnc v*7umadius 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 circulai 8i+djg /1smjr orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moonjm1i8si j /+gd A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is bie1 )if6va,abmtu -9$7.78 \times 10^{11} \; m$ 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 isn-izs,+ dn-au c(stm3af -mq ; the average distance fro-q n ,imu--ascd;fz+3 n(smatm Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)