Is it possible for an object moving with a constan6w yx h*9;hsuot speed to accelerate? Explain.wxu9 *yo s6h;h

  Consider a particle moving with constant speed such that its accel6b6tbl 4, txbkgigu3;5itw 6ieration of constixiilgg;b5t6t3ku, 6w 4b6 btant magnitude is always perpendicular to its velocity.

  An object moves in a circular path at a constant speed. lgzlyo8k (9 .fCompare the direction of the object's velocity and acceleration vectors ky8go9(fzl.l .

  When an object experiencesid. h(ov99d*u+hn.f ajtof .u uniform circular motion, the direction of the acceleration i .ju h9oiv.h *.+off(tadu 9dns

  Consider a particle moving with constant speed such that its a,fcueu)r0:7 xa4 fubw cceleration of constant magnitude is always perpendicular to its velocb7wur0,c e:xf4)auufity.

  What type of acceleration does an objecti; h i79yymd-u moving with constant speed in a circular path expeihm; yyu-79di rience?

  What force is needed to make an object move iwv cw. l)+)cyfn a circle?

  When an object experience4ehips ;h8o pcor;/s4e( ;/yg rs jq3es uniform circular motion, the direction of the net force ie(oqg;ie j;4cshse8y orrp ;//shp4 3s

  A roller coaster car is on a track that forms a circular louk,. v 5p xvml5vm0)tuop in the vertical plane. If the car is to just maintain contact wi55.)uvpumm xkv 0 lt,vth 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 thataqopo1aesx q2j;c27+ forms a circular loop (radius = r) in taqxpe72 q; 1+o2cao sjhe vertical plane. If the 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 th - m8d *g5 vpgq:pvbfk1yv-o04c6vcg v aqe+p7en follows a semi-circular arc until it is going straight up. Jupv pkgv4- 5p7gbgv+v8vcf1 -6q*coe:aqd0 ymst 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 curveof05h8 lpxa7 l 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 cozhqnu-.stmp(2-qyexvh h.k . 6 rxz81nstant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car asnpx 2h tx.1qr.vez .h6-k-yms8hzq ( u it goes around the curve for the second time, compared to the first time?

  A car goes around a cus-*s)lgr8m dx rve 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 the car as it goes around- *8sxm)s grdl the second curve, compared to the first?

  A car of mass m goes around a banked curve of radius r with speed v. I 46mowzr mq)za1jv, p*f the road is frictionless due to ice, the car can still negotiate the curve if t ,6r*mqz1p4aw voz)jmhe horizontal component of the normal force on the car from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are67 ayhdsc37b ) -ud6exbw9res 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 radius curve is v. What is the safe speed on the larger radiuws eh 6d 3dy 7rbaeb)79-c6xsus curve?

  The banking angle in a turn on the Olympic bobsled track is nod22jhokwr n(;t constant, but increases upward from the horizontal. Coming around a turnokh dw2r2;(nj, 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 movi9(hq)m.dbqo l/0 oge yng around a circular path to have both centripetal and tangential accelqhq(b.lgyo) e /d m9o0eration?

  The gravitational force between two objects is proporrrbs* h8 q55/ ef(qglktional to

  The gravitational force between two objects i-yyyq w/1ki i iym2tqbm,0d*;s inversely proportional to

  Two objects attract each other grg0k w,n8u hsbo cd: w+u-j51jyavitationally. If the distance between their centers is cut in half, the :swjwcogh+ kj51,d n -uuy80bgravitational force

  Two objects, with ma.45fg , q bpy3bshoiq9sses $m_{1}$ 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 masssjooe:,2 cj7y3kfx . fes $m_{1}$ 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 univer zd37n gi-*p 9ergfc+rsal gravitation.

  Compared to its mass on the Earth5ng2ss,rcuq(6lje 1yx az))m, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixth what it is on Ebi)p3l o8j zdj/ 1djobarzjh6z );h 5v/ke7 :tarth. An objectzdt aje;:7vhpzjhjo1)zb/3j b65 i8rld /k o) of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away n2 wm1t5 j7otgfrom the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is6hdm xxck9. u+y2mhq2 it beyond the pull of Earthm+c2 2x.ud hh6q yx9km's gravity?

  Suppose a satellite were orb8taht7/ i1acnf3svex,x o h((iting the Earth just above the surface. What is its centripetal 83x (n1,h i7cat(a t xsov/hefacceleration?

  A hypothetical planet has a mass of half that of the Earth and a radiusaz x lgss/fe0)40.,9 zpqbtld of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to 0l0zf9p se 4 x,b/ sgtz)lqad.gravity at the Earth?

  The acceleration of gravitbo or r34(pn4vy on the Moon is one-sixth what it is on Earth. The radius of the Moon ipb4v(34r nor os one-fourth that of the Earth. What is the Moon's mass compared to the Earth's?

  Two planets have the same surface ;9+ +t qhsvhdfgravity, but planet B has twice the radius of planevhqt ;+ dh+fs9t A. If planet A has mass m, what is the mass of planet B?

  Two planets have the same surface gravittw3u- zz(n4ri y, but planet B has twice the mass of planet A. If planet A has r-i43wnuztr(z adius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius ri6p jqy35 v9sczp6;esbke +5 p) about a spherical planet (mass M). Which expression gives pqpy59;+63vc56 eis j ebpzskthis satellite's orbital velocity?

  Satellite A has twice thzto wj8us( /rt0 za, st (z-bprq* 4ns/asc4b6e mass of satellite B, and rotates in the same orbit. Comp tb*aj/rt4b szou sz8zqc, 4ptars0 /w(-n(s6 are the two satellite's speeds.

  A person is standing on a scale in an elevator accelerating dow ) n:+rt;jew,qvcvf0anward. Compare the reading on the scale)jvf0+na tr, eqvc ;w: to the person's true weight.

  Who was the first person to realize that the planets move in elliptical paths army- h2g; 6ozeaound the ay6e;m -ozh2 gSun?

  The speed of Halley's Comet, while traveling in its elliptical orbit arolhr4 :pjpy71pund the Sun,lp 1pr pjh:74y

  Let the average orbital radius of a planet be R. Let the orbital period be aw wz:1e1 byv.T. What bevaw:.y 1wz1quantity is constant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromx/i +xagmaquh . a7; ,fh2,ewneda, with the same orbital diameter a,ah im ,a7hx+x/ fe;gu 2aqw.ns 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 Earthobad+4x 0cq -e to the Sun is defined as one "astronomical unit" (AU).qa dbce+o-40x 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.+trl )osv7o.wmz wh0 2

  List the four fundamental forcesrd eb n5 cio+0t-uc,5 w 5uvza8q/1.u qdczh/k in nature.

  An object moves with a constant speed of 30 38 ng1 xspl1dim/s on a circular track of radius 150 m. What is th 831pgl ds1nxie acceleration of the object?

  The maximum speed around a level curve is 30.0 kmkhh+0ajo6 0 hq/h. What is the maximum speed around a curve with twice the radius? (Assume all ah+hh 6kq0o0jother factors remain unchanged.)

  What is the centripetal acceleratixwoozpoaw6:zbde/37j r :pz 9)a mu-.on of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bw) .p3morza: j 96pzxbz-e/ od7uowa:ike is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the ax*qx ukphx6-hbsj ,i27gruf82is. What is the centripetal accele68k,*qfj-xsb h2hup2x r 7iugration?

  How many revolutions per minute must a circular, rot:e a hpt32rv.(9f oistating space station of radius 1000 m rot2it:v .p3ra(stoe f9hate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around asr 0sdlc,p1 qflxm5/q *n,4o cwrrd/6 13.7 m radius turn at 96.5 km/h. What is the centriperror0/ dn5lf c lq/p*,x s14sqdc6m,wtal force on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m strin; qwn-nm6 of+ag. 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 thm6nf q +wan;-oe string is not to break?

  A stone, of mass m, is attached to a strong string and whirled in a vxe9vy. mrmcb5 3p y2 9fiosq70ertical circle of radius r. At the exact top of the path the9 oe m5c fysxpbv3yi97q0r .2m 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 kc39jajkh ;e)strong string and whirled in a vertical circle of radius r. At the exact bottom of the path the tension in k; 9 )ah3kcejjthe 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 pul4i8jgl u;lb .3ah1mwy x:/*kygmu+0r5fiwu tling out of the dive. Whatu h k*5f libx;um.gj8g:t+w4iua 3w0rmy1l /y is the radius of curvature of the loop in which the plane is flying?

  A pilot makes an outside vertical loop (in wkbo5f u9 zn41c(wz0k2 q wv9dihich the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his se5w 0wz4d2 cv9o qk( 1k9zufbniat with only one-half of his normal weight. How fast is he going?

  The maximum force a pilot can stand is aboj d*9 bfg i )hch9)*hqmc14jx*zlp ih9ut seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can j m99iq h)x1cd *h)gl h4j9cb**hpizftolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve w21iom z*2bn.f ve vwu7ith the tires on the verge of slip 2z2f*mu7v1.nve ow biping. 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 fh53jm gek3 iuns:k zf6xf4s 46i4wz.elat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided b:4 e4iwsignzm5.3 f e4hfsk6jux6k3z y friction is $1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50tsnl+khbl j )g, vm+9* m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road for the car tos*j,+hlnm k)+l9b tgv make the turn?

  A car is moving with a constant speed v around a level curve. The c;e1gztwax msk jhep ta6 z2 j33/xj7:6 /5guxioefficient of f/h/iaxjx6etke 6zg j1gjzsw3;m 3a5 :x p t7u2riction 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 bobsled to ne(5h2 r ck ysgsrym1 ziss1fr f x(i6:9x(omh)8gotiate a 100-m radius turn at 35 m/s without srk 6yr:2r 8zmf h xss1x5gi)(fm1(9sshy( oickidding? (Ignore friction.)

  A horizontal curve on a bobsled run5dogdbbb6, el: t ,7gu swlgae36b5 +q 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 ra0r(v g;p4w5j lko.miu 1+vgfwdius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is banked at 0otic /g04: o r*v1oj:qjedsc$45^{\circ}$. 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 horiz i31/qd,evbb nontal circle bd3,1q i/evbnof 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 accelerates at a unitypznp588e )z form rate to a s 8pzzp5n8tye)peed of 45 m/s in 15 s, moving on a circular 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 proton tkxfo :u mt kd2dl6)pe h q,d.l1+*wqc*-s,r iof 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 standing on the Eartd7r ngtk :ld0 +8w ( 3z2gmfar*machu(xrjj-/h, due to th0h 2c+g7jaz m8uf *rw:tax(g jr3- ndrkdlm(/e 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 bw9s: 6 ns1e lq7)ex-ix9bwzsaetween two masses is F. If the masses are moves97 :as9eb-qwzxxs)16le w nid to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at what distance from the21ujhl 0fka le7pd 4v ti n6ky2-.mhk: Eart6l.ka4h ukvn0l2 -:1yfp i2t mhdk7e jh will 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 istco:072z gh yz $7.4 \times 10^{22} \; kg$ 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 distance above the Earth equalz1 1t3c03ofl zocc(lt to c1l3lc3cztt 0z fo (o1the radius of the Earth. What is her acceleration due to gravity?

  The radius of the Earth is R. An0j/s* w6uy jjt what distance above the Earth's surface will the acceleration of gravity 6w s*0nyjju/jbe $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal t.io(2nu+dnqcca- w8(psjjvow 9 10fto 3 times the radius of Mars. The acceleration of gravity of the satellite, as compared to the acceleration o0- sc djip9w8wao 1nj .(o(vucf+2tnqf gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration ofy3zk 0abe.cv8+g plx 0 gravity iezc +a0k. l38v0xygpbs $32 \; m/s^2$. 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.3nmh n r12oc:0ll:gyp The Earth has radius r. If the object is rainy: olcr3g2l0 1:ph nmsed 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+ sen 6el wv2z5g,jjapzmn;dzw6w.) * goes from sea level to an altitude of 5000 m? (The mean radius a 5 nz ndv6pslwjjw)ew;+*6mz.2ge, zof the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A sat+vkpwswfwf r7i// n63 2urpn4s )1rffellite of mass 100 kg is at a point 3r above the Earth's surface. What is the satellw/nfwfs 62 +kfi)r7 4f vwrn/up3p rs1ite's weight?

  A spherically symmetric planet ,4c2myllx* ze has four times the Earth's mass and twice its radius. If a jzy ,*lmxel c24ar of peanut butter weighs 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 Su4j pn6fuuyr5y*0k +d7lpw2ven all lie on the same line, with the Earth bjeypd2 u 5 f46uyl7vn +*wkr0petween the Moon 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 transported to the Moopb -55zff *cdrn.
(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., it2o svk:*0mbm w just skims the surface of the Earth). What is tmwkvms :* 0bo2he speed of the satellite? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low cgj6 l+)5nk ner ky qp0(uj;,lkircular orbit about the Earth (i.e., it just skims the surface of the Earth). How long does it take tolkyk5 0r q pg(l)junkjn;+e 6, make one revolution around the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbrj+x 2s*e(2 amsh *rzuit 230 km above the surface of the Earth. It is observed to have a period of 89 m hjs* 2xrmza+ *e2s(ruin. 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 diamet-r3dlq68j *mv3wkuqfx1 cg. ler 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 .n j,)dh t8pkywith 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 haspgg7:v .pzes0j :uiwq9 c +7uw orbital radius 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 complet:9 c+7puvpig.7:qz0uew gwjs e an orbit?

  The planet Jupiter is /3oy*orfg* ;qcqxi8b $7.78 \times 10^{11} \; m$ 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 is the aver mf; 0.dw2iculage distl m0.2i;dfuwcance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)