Is it possible for an object movi *yfow+h +)tetng with a constant speed to accelerate? Explain+ttf e*)ow hy+.

  Consider a particle moving with constant speed such that its accelerati7erl n*;b cs/uon of constantl;n*7/cub re s magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant ssej /.gjqz:-4ah,w 3q)x xz kepeed. Compare the direction of the q,ae)zzxjqjx.ke w- 4h :g3s/ object's velocity and acceleration vectors.

  When an object experienhb+su mx+6nl;ces uniform circular motion, the direction of the acceleration xbm6+;l+usnh is

  Consider a particle moving with constant spmawvi* (;.d hkvjf0 , +wsxl(teed such that its acceleration of constan; *hs+wt jwd.(vmf0 axk,l(v it magnitude is always perpendicular to its velocity.

  What type of acceleration does an obp7k tw ,(6cfovq) qoz.6zyb( i 2h6gvfject moving with constant speed in a circular pvv.627( b)zp6c6o(ykwfh to f igqz,qath experience?

  What force is needed to t+ x pi* a ;s;,bnbpjeh,8k-vlmake an object move in a circle?

  When an object experiences uniform circular motion, the diren; cx i9rq)mlhf8 6x,yction of the net force ishl; yq9,)mxx6 nc i8rf

  A roller coaster car is on a track that forms a circular loop in the vertopgbuir, h8kmft01g 6/el (:aical 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 accelera/gma 6g8t1 ,:f ioehlu 0rb(pktion at this point?

  A roller coaster car (mass = M) is on a track that forms a circular loop (ratzanh r: 2h/b/(g,6xir hid3 adius = r) in the vertical plane. If z:hatxb,a// dgirh n6i rh(23the car is to just maintain contact with the track at the top of the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circularq pkpm1n 76i5 m2(prxd arc until it is going straight up. Just as the plane is at its lowest point, the force on hi i6(mrd n 275kppqxm1pm 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 cuwi x6ap4vfss1p8jv2;5 4 maoqrve of radius $r$ 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 govtxe6tois9j na8x:i . 158nojes around the same curve at half of the original speed. What is the centripetal force on the car as it goes arou ox8sxt:n 8.io51tnj6j9 eiva nd the curve for the second time, compared to the first time?

  A car goes around a curvejro*b*zj lm,xep zu+)(uc gc1 f* 8 re8a6w/jl of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on thezc/jflruep6* o8)c am+uxrlwz* 8e( jgb j *1, 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. If the roh5fp7co j94fps.k .nhyn*s n 9ad is frictionless due to ice, the car can still negotiate the curve if the horizontal cfpp9.nchn*sf.n 95yh s 4kj7o omponent of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on b+;hc 1bl0/s .dzldfx) mbnu0a 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 smal ulf)bdnx +./bl10d ;sbm h0czler radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the 0-bnm *mzl5 ifOlympic bobsled track is not constant, but increases upward from the horizontal. Coming arou 5zi-*n0 fmbmlnd 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 and0;5wx mz(p s pqb5;kd object moving around a circular path to have both centripetal and tangential accelera (p0zd5qwdpk x msb5;;tion?

  The gravitational force betwee01h)1gg xsheln two objects is proportional to

  The gravitational force between two objects is inversely proportionhfd/e :/lofg, al to

  Two objects attract eacv9888 qzkgms mh other gravitationally. If the distance between their centers is cut in half, the gravita88sm qkgzmv89tional force

  Two objects, with masses zynel 73u.6fk yr 7,fy$m_{1}$ 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 massex cna0g 7p2fx2s $m_{1}$ 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 univercem54mo *ch-ssal gravitation.

  Compared to its mass on (1 p/dmvb 6taqthe Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it+ wetp 8i5yre0 is on Earth. An objecer pw0+85i ytet of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surface,p2(xsiv3 qng 7 the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pullv *a:fz -cv4uf of Earth's gravf*-z uvvfac: 4ity?

  Suppose a satellite were orbiting the Eny + pjkqpq) 2t6wa5:parth just above the surface. What is its centrik+pn5wtyqp:j 2p)6q apetal acceleration?

  A hypothetical planet 7ug,q4w am ky7has a mass of half that of the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the wk 7,amug4 yq7planet 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 on Earth. Thezl 5tof,,5r5dyml j.9 qei0bb radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to l0im.5 zb,9 rq o55edjlbf,tythe Earth's?

  Two planets have the same surface gravity, but planet B has twi ecp;vhrlqhg9 2.6s. -w:uf a1kotf5k ce the radius of planet A. If pla ta:f uhkwesv;6..gq-2o hlkrf1 9p5 cnet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but plane we/no/gcz/c ,t B has twice the mass of planet A. If planet Az noew/,c/ cg/ has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about d:ro.ikyl 7, ca spherical planet (mass M). Which expression gives this satellite's orbital velocity r:iy7k,cl.do?

  Satellite A has twice the mass of satellite B, and rotates:a.j1,- dvdwj5 t6y:qmq ow ow in the same orbit. Comp:1:a qjwt dy.omjo5q-w d ,vw6are the two satellite's speeds.

  A person is standing on a scale in an ele 1x61by g2tx1ik5wp bmvator accelerating downward. Compare the reading on 2myp1tx16 bg1ik xwb5 the scale to the person's true weight.

  Who was the first person to realize that the p (c)o sd ndfzn.p;d37ylanets move in elliptical paths ar.yc )d;s37zdonpd n( found the Sun?

  The speed of Halley's Comet, while tra:+zi*/ nraby/9.q:dui fftiaveling in its elliptical orbit around the Sunyirau/i9.f*i:a :/bdq + ft zn,

  Let the average orbital radius of a planet be R. Let the orbital pd e8ce :tj;8tqeriod be T. What quantity is constant f8qecd et8t;: jor all planets orbiting the Sun?

  A planet is discovered to orbit aroe uk9dct xt6ci19*ls+und a star in the galaxy Andromeda, with the same orbital diameter as the Earth around our ut9k6i1 +*ecdxc lt9s Sun. If that star 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 defined as one "astronuwx-mdd -u, )bomical unit" (AU)., d-u-bmd) uwx An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws. cb9sn. na()bd

  List the four fundamental forces i(h k ud;pt 8pn7io/am:n nature.

  An object moves with a constant spet- ob/2 at3orb:do/gxed of 30 m/s on a circular track of radius 150 m. What is the accelerationd: x g/trba3t o2o-/ob of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the malok,e2hw/ cy0ximum speed around a curve with twice the yh,2wo0 l/ce kradius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter ofx3b*f:+wf94sqts ajb a bicycle wheel of diameter 70 cm when the bike is moving 84 q:f*ss9ftbw + xja3b.0 m/s?

  A point on a wheel rotating at 5.00 rev/s i5 n1 m*(h oqitbfb7lu0s located 0.200 m from the axis. What is the centripetal 7uimb*tbhf0n15o ( q lacceleration?

  How many revolutions per minute must a ci,* qz/wdm l3dfrcular, rotating space station of radius 1000 m rotate to pd lwdf m*/,q3zroduce 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 at 96.ycl)hc4tdd j n.xi8). 5 km/h. What is th8 jli ).hc.xy)dtdn4ce centripetal force on the motorcycle?

  A 0.50-kg mass is attached to the end t1qmm: bz:-mb pqa n:kb391 jqof a 1.0-m string. The system is whirled in atmpm-b z qjbqnba 9::m1 1kq:3 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 string anho3u.ic) ,fev d whirled in a vertical circle of radius r. At the exact topuo 3cfevi.h ,) 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 attached to a strong string and whirled in a dqpf7kck+lso:0:x 7 zvertical circle of radius r. At the exact bo0+:sp7kz:kfo q xc7 dlttom 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 pulling -,wptcp/) ovj out of the dive. What is the radius of curvature of the loop in whicocw tv,-/p)pjh the plane is flying?

  A pilot makes an outside vertical loop (in which the center of p -mzy(i-7 w.ehw pme/kl99ykthe loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his se7 yw/hp-mz( w.9yik 9pemel-k at 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 wei0sj* sl a;mn4yy5zm4ught. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed o*m lmusa4zysj05 4y ;nf 250 m/s?

  A car traveling 20 m/s rounds a 9 futoz8igq:hyl0a(2 n 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a szot0gfy h ( l82a9uiq:econd 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 ra7-m+madqxv/ g dius 50 m with a speed of 20 m/s. The centripetal forcgm-x/ dm7aq+ve provided 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 m at a speed of 14 m/s. What yh, +:faxk be66jl2*rgjdp 5ymust be the minimum coefficient of friction between the tires and the road for the car to m hf+2dl:6j6byap *5jy,kr egxake the turn?

  A car is moving with a constant speed v /c*iv7 py 4zgexcdgy2z 8acdn(/za8 +around a level curve. The coefficient of friction between the tires andpc(/ 8dz47gyzadig ya2/8e +n*zc cvx 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 bobsled to nerj :7w r)7sdyhgotiate a 100-m radius turn rjd yrwh7)s:7at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a .es* i0yeto yt2l6 t1hbobsled 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 10 v uzpn9hjdph.-nhb19z0;.n l0 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m,t7xgh hxktk57a dmlv 58)l 7z is 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 unifo1lgc ;2 + cnxze;t;/ nz0knozg x*:;eb udahi,rmly in a horizontal circle of radiuel zbx;zn2gc dx/+*c0tin;e ; ;uhan,: zg1kos 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 accelerates a61xd08z b dmxbf64dpct a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of 8z4c1 0d db6f6dpmbx xradius 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 of a pc1xj: 9 ;bk3xr- oaijjtd1rq0roton 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 7.4 +yvm2f vgmj0-kg person standing on the Earth, due to the Moon? The mass of the Mo mj.f2vmgy v+4on 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.jr 1xihay 5n9hg5l g,ps;s* 5f If the masses are moved to half of their initial distance, what is s5hlrph,1g x5say *fjn;5 9ig the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what di oe9nrdsy tlk onl*u6u8(:, e7i(i 3ye zt3oi6stance from the Earth will theerol 6( (tods8l inou:t,i *6yniu9 7ezk3y3e 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 is 10a55qnc)naqj2y3 y tm 5)ofevw;cmf$7.4 \times 10^{22} \; kg$ 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-wal js5 ,cs1;,xzsyq 481dt ; hocxrundn(k" at a distance above the Earth equal to the radius of thdd;syc48(rnhs x5 1,z1tno, scx uj; qe Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will 5a (tx1vgsdf.the acceleration of s1 t(fxg5 .vdagravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 time09vc(jdbpd ,eaxi9y0 s the radius of Mars. The acceleration of gravity of the satellite, as compared to the cvi0(e90 jbd9ya xd, pacceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planxvft/wd)r :-g /.s/- zg z biydw.-rtuet's center, the acceleration of gravity d r .y.gw- tbfsd/ -/x-wt/:vz rzui)gis $32 \; m/s^2$. 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 radiut+/pmx3q+wmz2 b) *rykg y/ /jfwft.ls r. If the object is raised to a height of 3r ab+lzw/*/ k3g.2 tw/fxt yrbfjpm+) myqove the Earth's surface, what is its weight?

  By how many newtons does the weight of uxwju) -; 3czja 100-kg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Eartxjw )u;-3jczuh is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is at a point 3r above tk8hpsd cq19qn7zd:xuq0 82m lhe Earth's surface. What is the satellite's 2c0n 1dmx89ukd zql7 q8phqs:weight?

  A spherically symmetric planet has four times the Earth's mass8s8 /wmn. lz+d foetwa ya,31l and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it w +moaty/,fw8n.8l d3za sw1le eigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same linehvzgg, +te;lj3i9y9rdl7cny :cd-z4 , with the Earth between the Moon and the Sun. The Moon has aeln ;yrg9djid ,z:yvzc43lgt-c79 h+ 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 transportedmwpfoojnzkz8mu( (n7- +l. qc 2 god69 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 t8k8*f ul wv x 1oowg:wvy8x8)zhe Earth (i.e., it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the Earth isw o xwvk8o8:8y uvwxzlf8)*1g $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., itfk .wk 5;avsa vjp0dl:1so65s just skims the surface of the Earth). How long does it take to make one revolution5adwflasp v;s6s5kv 0:jk1o . around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km abov o;p:o -.t3a tw*epsove the surface of the Earth. It is observe * :veptao;pto3s wo-.d 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 orbital diameter of 6og1e+a 5fgn e$1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the planet with a r5g)9pkz tr,eiadius 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 hj(0bx 46u pjbuas orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orb0 juxp6 u(b4jbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is e+ . /ers asei)p0/x55bomtr vn .oaw/$7.78 \times 10^{11} \; m$ 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 1cq9i ,pfw. 4 ok5kuf9h2 years to orbit the Sun once. What is the average distance from Jupiter to the Sun? (Twucok ,kf9hp9. i4 qf5he distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)