Is it possible for an object moving 8g,:h 2 89mrevhjslbrwith a constant speed to accelerate? Explai er h8:r2bmjg,hl 8vs9n.

  Consider a particle moving with constant speed such t3txrb w )z,(oyhat its acceleration of constant magnitude is always perpendicular t(r b3), tozywxo its velocity.

  An object moves in a circular path at a consuj+f d/9cc)3e e z;e i+z97hojj9wkq wtant speed. Compare the direction of the object's velocity and aq9cee9u;c3wzo+jh 9zwd/j+k)e7 j fi cceleration vectors.

  When an object experiences uniform circular motion, thq1e* 4jc5d6dykyu 5pt4sjyy5e direction of the acceleratiqyy54u41 t*c sp edy 5k6yj5djon is

  Consider a particle moving with constant speed such that its acagwk*,q,z5 nk3rjd- o celeration of constant magnitude is always perpendicukr-k3 g*qw,,azd5j nolar to its velocity.

  What type of acceleration does an object moving with const d-dbr ,/ )ddu:mz7muxx(;wz ki4br8gant speed in a circular path exp,bz7)d:w4uigzk 8;- urd(mx /ddx bmrerience?

  What force is needed to mqf)t)6,f 7ycrgkt g4u ake an object move in a circle?

  When an object experiences -c a+d,mvw*auib )r0zvze mq079f 8byuniform circular motion, the direction of the net forcibuw- q ad) mcmzze8raf0v 0 79b+*yv,e is

  A roller coaster car is on a v,av*p)i f sc+track that forms a circular loop in the vertical plane. If the car ip)i *afc svv,+s 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 on a track that forms a circular loop (rzlm+z 5 h n+6icat2jj5jnw-f.adius = 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 valuemifzj j+2wz a +nj lc55.n-ht6 for its speed at that point?

  A pilot executes a vertical dive then follows a semsl,qs .6 tnwrn87w8rji-circular arc until it is going straight up. Just as the plane is at its lo86lwjrnsr ,.t8 swq n7west 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 radia.taal hr 57x2 ,vc0bkzt-(l vus $r$ 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 at0j30, fjgx rgd a constant speed v. Then it goes around gdj,j30 rfg0xthe same curve at half 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 y0hf a88y+-xzch bj ) 8ephhk,goes around a curve of radius 2r at speed 2v. What is the centripakxh0bhheyh,pyjc zf8 8+ )-8etal 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. ea xp*w .gqh51c3r2wbIf the road is frictionless due to ice, the car can still negotiate the curve if the hora1rw*3.x52 phgebqcw izontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run arelr71xl-adhy k)th4.6i ol +kw banked at the same angle, but one has twice the radius of the other. The ok 4khwtx 6.hyl+1l7 la d)-irsafe speed (no friction needed to stay on the run) for the smaller radius curve is v. What is the safe speed on the larger radius curve?

  The banking angle in a turn on the Oc9zbi+,u /+h9 :ef;/gmsr dos1qe/e jphv0 pjlympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb the wall," then go lower c +u/+;,jp19 0qoeez bvcs/isjmpheg/f:9rdh oming out of the turn. Why do they do this?

  Is it possible for an object moving around a circular path to ha;d8 otx )fj xnv3c+*rwve both centripetal andftx3dn+; 8wr*xvj) oc tangential acceleration?

  The gravitational force between two objects is prlu5iil l0 u q,)h;sfq 4g8u(mpoportional to

  The gravitational force between two objecvka zxf) t*-(oh1ga)g ts is inversely proportional to

  Two objects attract each other gravitationally. If the distance between 2*4byog.qh)v k(b .muqkoco k.8 hyp7 their centers is cut in half, the gravitatio*omqp8uy2g.b yvb( q okkhk.) 47c h.onal force

  Two objects, with massft a n-:4t5lqres $m_{1}$ 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 ma o z68o5g6nnwusses $m_{1}$ 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 universa; kamr8wefb/+l gravitation.

  Compared to its mass on the Ea 7wx yjk-:tm-hrth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is onemfp,f kny-1t6 -sixth what it is on Earth. An object of m1ymnf,fkt -p6ass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's sur8fpdk8xm)s*(wfyd ,dface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it beyond the pull gvkm,;), tu4ctub x* ss*g 9dfof Earth'tg*f ,xtbgu sck; *49s),vmdus gravity?

  Suppose a satellite were orbiting the Earth just aboxbyque;s g2. ( osbn+o,qr)r- ve the surface. What is its centripetal accelerationqy g.s)o-nbru+x(se2 ,b;oqr ?

  A hypothetical planet has a mass of half that of the Ear62kd m/-m;r9 ylmmp8hjj. kqq305gh/ft nknt th and a radius of twice that of the Earth. What is the acceleration due to gravity on t/rqmjp6hhfm25/ n m-k nkmtt yg8;lk 90d3qj.he planet in terms of g, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Mopztj x4; +shr)on is one-sixth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. What is the Moon's mass compared to the Earth's? rpxs4jzt;+h)

  Two planets have the same surface gravity, but planet :vr6q7eruk, wk syjv.nog )89 B has twice the radius of planet A. If planet A has mass m, what is the mass of plk:euvnov sw8ky.7)r9rj 6g,q anet B?

  Two planets have the same surface gravity, but planet B has twice the , xf7+u tg-buzmass of planet A. If planet A ha zx,+tf-uug 7bs radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sphe8 ct*n5 ma 2i-o .aidr1zuod5hrical planet (mass M). Which expression gives this s h io*5cnao .mt-85z2d1raiu datellite's orbital velocity?

  Satellite A has twice the mass of safm1mmyp q:a.( tellite B, and rotates in the same orbit. Compare the two satellite's y( pmf.:1maqmspeeds.

  A person is standing on a scale in an elevator accelerating downward. Compar x)mt mi0:q; em-2ded 1 ktq5ms+pglw8e the reading on the scale tokd;:58m)q+ m-p2qeegmsi m0ltxwt1 d the person's true weight.

  Who was the first per)m3 nb yuf i3b(kyvd*4n9l1u rson to realize that the planets move in elliptical paths aroun391fub i3mduyr* yl(kvnnb) 4 d the Sun?

  The speed of Halley's Comet, while traveling in its elliptic,q1d p 1 etdy*ahukf0v06k(p pal orbit around the Sdp01vkk( yf upqp0t dh,6a*1eun,

  Let the average orbital radius of a planet be R. Let the orbit8n* .7h2 tdn6 jrewl3ji5knuwal period be T. What quantity is constant for all planets e .*23 wi5utdn jk8rnj nhwl67orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromo;iyolohf. ph mh .31(eda, with the syh3 .hmho li .op;f1(oame 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, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun is denbpbd37go (h( d7j px)fined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average di3bj x p(b)n7ogddh 7p(stance from the Sun?

State Kepler's laws.pk+xg,q3di;go z1q y5

  List the four fundamentadytt.ukd8lz1u.kmziz77*ryw *7,z cl forces in nature.

  An object moves with a constant speed of 30 m/s on a circular tr69o ; 2ccz6imvlsm,wi ack of radius 150 m. What is the accelerati6,zi2l96iccm;v m swoon of the object?

  The maximum speed around a level curve is 30.0 km/h. What is the maximum spk2edhym n6rp b780( uneed around a curve with twic02rb678(m npund yk ehe the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimeter of a br6cb gq8 p p33/hq* 6zhems9hvicycle wheel of diameter 70 cm when the bih3mhg * 6p/9zq 8pc6bhe3rs vqke is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/ ty8ly ctdux.k9c v(cgud:4+( s is located 0.200 m from the axis. What is the centripetal9+v:y8ygclut(4 . k(cx tuddc acceleration?

  How many revolutions per minute must a circular, rotating space station of qt;vr4t e+wuzf* kt9 c* ,kt0oradius 1000 m rotate to produce an artificial grar tzoe4c9,tk 0w k*+vuf*t qt;vity of $9.80 \; m/s^2$?

  A motorcycle has a mass o8, /: yl: (zs4fvvzp*ajidv chf 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h. What is the centripetzvcv:4 d i,say:f(z/v p*8jhl al force on the motorcycle?

  A 0.50-kg mass is attached to the en5nyi*t nl a0m1d 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 350 N. What is the maximum speed of the mass if the string is no n al*105yintmt to break?

  A stone, of mass m, is attached to a strong string an jz6 ;0;myyjp;3qb.qsa2ladn d whirled in a vertical circle of radius r. At the exacby6sapl0;zjd mqa jy .n;23q; t 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 attached to g(xuwxvzt fo ((jj-*5w- xvc9 a strong string and whirled in a vertical circle of radius r.u (ct-v( zwxjxojw( fvg*95 -x 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 600dj 1qh*,x)z tyc/8zqf m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of the loopz/ 1 qfh,tqy*dcxz)j 8 in which the plane is flying?

  A pilot makes an outside vertfk 7 )d,roak1jygb,: uical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is p)kd rb,kf gu1 y,jao7:ushing 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 tima18ot:a8bco wlxy ,2v es his weight. What is the minimum radius of curvature that a jet plane's p v xa:8ot,a owy2b8cl1ilot, 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 radius horizontal curve with the tiovu-n p k13uehg6 23tvres on the verge of sl k2u6vt33p ho1enugv-ipping. 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 f1zv l40g:e 6qzc4 nxg8xrdx ;vq3dpk.lat curve of radius 50 m with a speed of 20 m/s. The centripetal84 nc6q:dg; 4lrdz zpvvq1 xk .exg3x0 force provided by friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat cul1ea6n 8hqp/yp q57)xpb 5zdah2dh/ brve of radius 50 m at a speed of 14 m/s. What must be the minimum coefficient of fri/pxh a)hldby 81q5p z d hpanbq25/76ection between the tires and the road for the car to make the turn?

  A car is moving with a constant s 4- kjnuxc0uv+peed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius 40x+-u kc nujvof the curve if the car is to stay on the road?

  What minimum banking an hexlh//qgkg;d z;)ey2or u /+gle is required for an Olympic bobsled to negotiate a 100-m radius turn at 35 m/s without y +)g lz;/ ;de/hh/gxeour q2kskidding? (Ignore friction.)

  A horizontal curve on a /y )*psz zllt (c2sjx2+ mn:zrbobsled 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,ib en3 a:5 gs6yecem0: banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bank7xc ui e 2p(:se4ds,wfed 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 endfqq ovk99)wz4vieheg3 0v.,k of a string is revolving uniformly in a horizontal circle of radi3g ,fvw )oqek9vvq 4e.0ik9z hus 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 caj30ixe tg4o8d r accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a cig4jt0 d eox38ircular 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 of a p5rvk 6g )ieg,c4z*)fv-g z t2b qttr6croton 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 stax-/ za xbfz; fpyut 4ilw69-)jnding on the Earth, due to theix uw)xj-z6 p a;btff4z 9-/yl Moon? 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 Ft/f k1cx5g)3clggb 6a. If the masses are moved to half of their ini51t 3gabc)kg /6fcg xltial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at whatj;riq9mj 2 u88*rte tw distance from the Earth will the gravitational forces due to the Sun and the Earth r9 *rj t;mwtqju82e8i 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 i zovdms5 r*.8auh(zk7 s $7.4 \times 10^{22} \; kg$ 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 dish7wu;winb f6 8tance above the Earth equal to the radius of the Earth. What is her acceleration due to ghwu76b 8 fnw;iravity?

  The radius of the Earth is R. At what distance above t2do zeow nshw 7b4* ea0o mz157p:nc5fhe Earth's surface will the acceleration of gravity be:oo ze*bma hc5se1pznf 472 5w0don7 w $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its sui nfo9r:+ o4gjrface equal to 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration of gravity on the surface of Mars, i: gr4o n9jf+ois

  At a distance of 14000 km from some planet's center, the accelerak t20z6o +h eo/qrcrxmpg*6* wtion of gravity ke+h/6cw rgrt q 6mzp*o2ox *0is $32 \; m/s^2$. 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. Th f0 9d4xwbwcc-j -*wkd8;kveu,cp5 dhe Earth has radius r. If the object is raise0p 9vu;-cw * c x,dwek85kdb4jhdw-fc d to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons hmbk)k3)sj7 m e7ve k8does the weight of a 100-kg person change when he goes from sea level to an altitu m7)8k)h3m7jeskeb k vde of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A2 oic a39(aeysqq- v0x satellite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellite's weighoi-3(q xaysq e2c 9a0vt?

  A spherically symmetric tvz al) h0gatjs3 );y+planet has four times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how mug tlzv;)j )0a ayh3t+sch would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie on the same line, with ; 9ydy4e0c1g65xke(jb tbxtf)hck/ bthe Earth between the Moon and th14gd(xc; /b xc5y6e ehbykt)t bkf9 0je 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 transported to the Mogha)8a rwdlm1e d56f(on.
(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-j3i c9 ym+f 7hz edwd+)hqij( the Earth (i.e., it just skims the surface of the Earth). What is the speed of the sat j 7(+fd+ih zw3qedmc i9hjy-)ellite? (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 rk8frm;yx/uw d/q/ 2u just skims the surface of the Ea/ w;fmq2y8xkru// ud rrth). How long 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 circular orbit 230 k2( w1y co7seoyw:c t8km above the surface of the Earth. It is observed to have a period of 89c yowtey2csw8ko :(17 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 diamxjo oe6ema:33iexv* 5, jt3tqeter 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 tx m/ny j 5cijxx09t1x qj2b;h+he 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 rv hq )oj+ ;evp d1f8iqu+a,8rpadius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete a; +apu8vihdq 1,j)oevq r+8f pn orbit?

  The planet Jupiter i (ck-. bk qllaul5q 0mz.qh23rs $7.78 \times 10^{11} \; m$ 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(0lq po9e2q3lrrdben )qfv)2 Sun once. What is the average distance from Jupiteop q0)drl)nbfev2(q3l 29 req r to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)