Is it possible for an object moving with a constant6kb j7ol8)p ioo yvam *3hom8; speed to accelerate? Explai;8o3vhk 6oo bi7jm)opya8m*l n.

  Consider a particle movi;ni,pqq i6 hq.ng with constant speed such that its acceleration of constant magnitude is always perpendicularqqp.i6hnq; ,i to its velocity.

  An object moves in a circular pay7 m7op(dw rdzcw,nt *:68 o)ze.cizsth at a constant speed. Compare the direction of the object's velocity and accelera p6 zwy z*,mc)soeind(oc.r7 zw t8d7:tion vectors.

  When an object experiences uniform circular motion, the dire/c.yt 2 s)lkhr1; brqa4xrai-ction of the acceleratioa-r r4brkt/y;2i x sq1c.lah )n is

  Consider a particle moving with constant j5 /*kswfezl5 speed such that its acceleration of constant magnitude is always perpend*jwef5/zlk 5sicular to its velocity.

  What type of acceleraf9(ek)o9dy;za pby :w tion does an object moving with constant speed in a circular path experienpe z:wad(y)9f 9b;k yoce?

  What force is needed to make an object move in a cim)uzbp 1:o49g0tr lgm rcle?

  When an object experiee8u 3 .z3v:jf/z1 stfg csryu)nces uniform circular motion, the direction of the net forcszg/ z3cy8svff3. u)ej :r 1ute is

  A roller coaster car is on a track that 2g1 ulu vt2z7lforms a circular loop in the vertical plane. If the ca1t2l7uzlg uv 2r is 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 ti(s 0 eb(wlsj1mnom( 8hat forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top sjli8 mmo0(1( wne(s bof the loop, what is the minimum value for its speed at that point?

  A pilot executes a vertical dive then follows a semi-circular arc until it 25t;l e pi7lt7roxoqd .d j)2jis going straight up. Just a d.ito5)pl727xrtjq2lj ;doe s 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 curve of w/) 7k7azno9moz*okpjz l ;z*(4 caki 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;u pq 6ks2 becl+6ya+d speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the lysapc k;bd e62++qu6curve for the second time, compared to the first time?

  A car goes around a curve of radius r at a constant speed v. The714htwk/tjlq/ hy do5+ ahbwfll/;qjd ka 3**n it goes around a curve of radius 2r at speed 2v. Wa/blhtq3 y/4 fjl+a 1twldqo7hk 5k;*dj h/*what is the centripetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a banrjejs: 5 p05uzked curve of radius r with speed v. If the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car:r5pjuz05 js e from the road is equal in magnitude to

  Two horizontal curves on a bobsled run are banked at the same angle, but one ha;i iq nm7mb)i9s 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 ;9iiqm)imn7b radius curve?

  The banking angle in a turn on the Olympb- xk toj5xvvq) g7plql149aiac 4-)xic 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 coming out of the turn. Why dov5ao4pxi)-g 7t vqcl4j)-bxq x a19lk they do this?

  Is it possible for an object movingbq88- eie8hp.rsca u9 around a circular path to have both centripetal and tangential 9qua8 pee.h b8r 8-csiacceleration?

  The gravitational force between two objects9l,s u ifxe5n(ar)a*c0izc9f is proportional to

  The gravitational force between two objects is inversely s moq*wke) 5;yproportional to

  Two objects attract each other gravitationally. If the distance betw)inwb q28wq .kdidja16+:9bt ogm) hqeen their centers is cut in half, the t9bbwo q) nh+j iq.mqi6a81w)2kdgd:gravitational force

  Two objects, with masses ek,.nwn7+yj d $m_{1}$ 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 masw2v kge*u ,8dlses $m_{1}$ 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 universal gravitat i t8th) so)2js1/epotion.

  Compared to its mass on the Earthqlt rmsr34f,h8/n mf2, the mass of an object on the Moon is

  The acceleration of g6o2n-mkwrk049cwowr ravity on the Moon is one-sixth what it is on Earth. An object of ma2- 0rmk49 www cnroko6ss
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from theo/y( dx( .thlb9av* vp Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. 4myoak/yj0c(w ko(9uy ix)b,At what point is it beyond the pull of Ear(kxo mb0wo 9i 4auc)jk /(yy,yth's gravity?

  Suppose a satellite were orbiting the Earth just above the surfavfg pw+ j-;*)iw;f cqmce. What is its centripetal acceler vcm)q g+wf-if;wpj*;ation?

  A hypothetical planet has a mass of half that of the Earth and a radius of twfs; biw6kjx4/l e5x( cice that of the Earth. What is the acceleration due to gravity on the planet in terms of x5/4kw6 cjx(esb; iflg, the acceleration due to gravity at the Earth?

  The acceleration of gravity on the Moon j-t u 3bdhwwy*)27 5 5xqrdnbwis 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 cxd5- r2t* )wjbdnb7w 3yh uq5wompared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice the rbj3alpai) 3 b4adius of planet A. If planet A has mass m, what is the maa)lib 3 ajp43bss of planet B?

  Two planets have the sambn39c ch0em (rm o+u1ozzkg :)e surface gravity, but planet B has twice the mass of planet A. If pl +:conrc (m hezg93m)oz0uk1 banet A has radius r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sp)ymcop ry..tp(:u+wxcf d)g9 herical pla:x(r c9+.uwpgdmyy ) cf ot)p.net (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotate58.g h81w0yd kzurtb+bqzk 9qs in the same orbit. Compare the two satellite's spd 9w8+8yz. b0ruh5 b1k ktqgqzeeds.

  A person is standing on a scale in an elevi*g-*yy/ jldnator accelerating downward. Compare the reading on the scale to the pers/ *ingly* d-yjon's true weight.

  Who was the first per.g+ *x mh4cr cm7q*uqsson to realize that the planets move in elliptical paths around the 4cc +. gs*mh7*mrqux qSun?

  The speed of Halley's Comet, while traveling in its elliptnvc ;e9dbqi7gg8f7 e,ical orbit around the Sugc7vfg , bqi de8;9e7nn,

  Let the average orbital radius of a plane(whub w-ipg+55zqzy xm,v m;8t be R. Let the orbital period be T. What quantity is constant for+vhz( -pgxq, bm8wiu;5m5w y z all planets orbiting the Sun?

  A planet is discovered to orbit around avcq0fu jmkt z3x5n6ep*/ck ,0 star in the galaxy Andromeda, with the same orbital diameter as the Earth around our Sun. If that star 5k j,6 czx*ku0cn 3qmve0pf/thas 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 +7ghq* yl bq0wuh0g8oi24kr ethe Earth to the Sun is defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroi4gl r02 8y*gw h+ uh0eiokbqq7d's average distance from the Sun?

State Kepler's laws.sv 5abx* +te4v

  List the four fundamental forces in naturef x:t zj62dc24b29i rh qop;bk.

  An object moves with a constant speed of 30 m/s on a circul,t5(7j vihjhg ar track of radius 150h gjiv5,h7tj( m. What is the acceleration of the object?

  The maximum speed around a level curve is 30.0 km/h g ,-sdza/hwx:(eizj +l (2ecf. What is the maximum speed around a curve wiis la:hje( d2 ,czex+ /(gf-zwth twice the radius? (Assume all other factors remain unchanged.)

  What is the centripetal acceleration of a point on the m nld7li3p a5-perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0pil7d l3ma-n 5 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the azknfl j:tr .56xis. What is the centripetal accrnz5. fjk lt:6eleration?

  How many revolutionsi*0z5nw diaj wrbn/ k;vw1+l. per minute must a circular, rotating space station of radius 1000 m rotatzin *1b;+ 0.l dwrj5iwa/nkwve 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 radi,y ;m*vzuswt,us turn at 96.5 km/h. What is the centw,uv s;ty*,zmripetal force on the motorcycle?

  A 0.50-kg mass is attached tn*i.s)ure j bgr*n u8 w6o0pq3o the end of a 1.0-m string. The system is whirled in a horizontal circular path. If the maxei.uj6p*n * nq0 uwrsg3ob )r8imum 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 sb7e pq; lgf0t-gcck jcc1v-2 :trong string and 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 weight. The stone's speed at this point is given 1f j- leggkt: 0c2cb-c7;qcvpby

  A stone, of mass m, is attached to a strong string and whirh0i 0 3r rkfw(bgd,cq.r5t.wx led 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 tkwx q0dwr,bi htg(.3fr 0.cr5his point is given by

  A jet plane flying 600 m/s experiences an acceleration of 4g when pulling edbo- lodo;x381rm:taec e;- out of the dive. What is the radius of curvature of the loop in whiord-e:1e ;bc ol ax;o3 etmd-8ch the plane is flying?

  A pilot makes an outside vertical loop (in which the c gep988qjamx1enter of the loop is beneath him) of radius 3200 m. At the top of hi 1gjxm8ea 8qp9s 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/m r.t*zxt* rl stand is about seven times his weight. What is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical div.tm x ztrl*/*re, can tolerate at a speed of 250 m/s?

  A car traveling 20 m/s rounds an 80-m radius horizontal curve withdml hxio/ ys8 q0/1f/t the tires on the 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 d1flm/qy0oi/h x 8s/t surface.)

  A car is negotiating a flat curve of radius 50 m with a speed of 20 ni(nrh*rr2gv 5bs x a.fh3-c6m/s. The centripetal force provided by n5rcrg-* vbx 2a3.i (hfns6rh 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 mus7p )j m,x j4uf+nw tbwh.5l;vtt be the minimum coefficient of friction between the tires and the road for the car to make the turn?, t5v7 xfwjnl4jmwu+htp)b; .

  A car is moving with a constant speed v around a le hqb da vkqh10x(bh(*k-ze-f 1 tjo4t;vel curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve ifjv;kh az *1qb botf(-x( ed-0hk1hq4t the car is to stay on the road?

  What minimum banking angle is required for an Olymt3orc9fl11 +0kwacc k7l 4+ddrxu:f b pic bobsled to negotiate a 100-m rad17alfb9cw: t4c dro kx + udk+fl1c30rius turn at 35 m/s without skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is bankmbelx.usqv g4 9)y+5f ed 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, banked afy ,snva*dr(, t an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m svwedbhuv;ka-)3)a 4be; ,yqis 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 endsw t*j(dth,g/wd:cc )-s8vg t of a string is revolving uniformly in a horizontal circle of radius 0tc gdtc :(gtd-,s *hww8v)s/j.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 uniform ratbm hln -/mlh hipx7/.g8k6yq6 e to a speed of 45 m/s in 15 s, moving onl /-6 87hm6ybnkh/hp. gqxm li 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 consiay* ( 0c:xbv s;0ldzx7w -+2 ialkivuvsts 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 person st+x 4:exg cr)xfanding on the Earth, due to the Moon? The mass of the Moon is x) x:fg4x+re c$7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attractive force between uv6ka9b3q 8 x:t)gncjyq78xt two masses is F. If the masses are moved tgqa 7cuxbxtjvn83k )69y 8 q:to half of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth towbfeo6msu ; )m9dr +0 l63/h*a zrunayward the Sun, at what distance from the Earth will the gravitational forces due to the S *+ saheou6b 6mf lnmu/w39)dy0;rzraun 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 Moondyz9y-x:fulyb 94 s k. 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 eom;1ek3)ox; lx.bab(1xk(2jpjcv o for a "space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acceleration duaxpj ( 1koc)3(k1xm e be;o vl;box2j.e to gravity?

  The radius of the Earth is R. At what distance above the Earth's surface will f :wg(awb/hr8 the acceleration of gravity b:fhbwgr wa/(8 e $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal to 3 times wk e m*,r6j+,sytk0zoiu6 z1ythe radius of Mars. The acceleratiy0,sok1t ,e+jz zumwir6*y6kon of gravity 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 centery;xwzd-ae+dpp 7e+( )6y m3*fx tpw t0y*t uwk, the acceleration of gravity+ ye*( ku-tfe*y)dy0+ ;pwppz t3axxwwm6t7 d 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. They d4:g-z5 stfe Earth has radius r. If the object is raised to a height of 3r gd 5s-y 4t:zefabove the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kg person change-, ( :j mr.t owxtpfy7azxfx:9 when he goes from sea level to an altitude of 50xwx: o9p. (ftjmtyf7x,r:a- z 00 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A sa5y:yg+k zeaz 51dvlu1 tellite of mass 100 kg is at a point 3r above the Eald 5vk1z5u y z:a+y1egrth's surface. What is the satellite's weight?

  A spherically symmetric planet has four times the Earth'r ;aovth0; jl6s mass 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 the surface of tvah j0l;ro;6 this planet?

  During a lunar eclipse, the Moon, Earth, and Sun ax- ojxa:u;cwd, f2-i+0 uhtqx ll lie on the same line, with thewuhcq,t x ox;:a-xi2-0jf +ud Earth between 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 tr6 yij403e0wyb 6qy rokansported 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 ;1d * t4qkyeyslow circular orbit about the Earth (i.e., it just skims the surface of the Earth). Whatyqd1;yk*es4 t 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.e., it just skims thelx:vttz0-inf83 6i l n surface of the Earth). How long does it take to make one revolution around the Earth? (The ml6nlz vnii x3t0 -f:8tean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 km above the surface of the Earth. It is ogswmligd0p, k9f:0) r bserved to have a period of 89 min. ,) klgimswrg0 9:fpd0 What is the mass of the Earth? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  Europa, a moon of Ju)* v 4rorzlc8e 80bnropiter, 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 vudz(x n.(p7)v7ofuwwith 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 plan(eduma3j (n u,et in nearly circular orbits. Moon A has 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 completu (mu3ed a,(nje an orbit?

  The planet Jupiter is vfj0z3m5rw fu:f94cwn u)r,a $7.78 \times 10^{11} \; m$ 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;(c k8qufiv2 :fk9sps to orbit the Sun once. What is the average distance from Jupiter to the Sun? (The distance92 k( uq8pfckissv;f: from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)