Is it possible for an object moving with a constant speed to accelefwq950 lb+euy(d1 d/9qy5l zt73px omceioy 6rate? Explai5l719ydmf o ed+zwbqy3 5c (6o/9txl0y upiqen.

  Consider a particle moving with constant speu5:-0j; ty 9n 3;-iw (jcpzskjfztnmwed such that its acceleration of constant magnitude is always perpendicular tc-;knf5(mjjwzjn w9tty ;p z s3iu-0:o its velocity.

  An object moves in a ci71q mpo.cmxoqxe 54w .rcular path at a constant speed. Compare the direction of the object's mo 1o mpwex547x..qcq velocity and acceleration vectors.

  When an object experiei,im9d 06y8aona 7 :/fexwvmznces uniform circular motion, the direction of the accelerationn /iif:ym,v8 ea9w67xzoad0m is

  Consider a particle moving with constant speed such that its acceleration of czsey :cv5.4w gonstant m4: cz yv5ewsg.agnitude is always perpendicular to its velocity.

  What type of acceleration does aj+ rza/p )w/lgn object moving with constant speed in a circular path experiencj/r /gl)w pza+e?

  What force is needed to make an object move in a circle?nfs(rus 2a16 dp t/rt-

  When an object experiences uniform circuo v/lh ehy069nlar motion, the direction of the net fornh0yo9vh e6l /ce is

  A roller coaster car is on a track that forms a circular jl p+xi)o/a( gloop in the vertical plane. If oga/j+p(x)l ithe car 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 that forms a circular looph19 bel 63vpyb (radius = 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 value for9l1v6bephby3 its speed at that point?

  A pilot executes a vertipl joo1fhd,jti0 3(+hcal dive then follows a semi-circular arc until it is going0opi31+ o(fjlh j,hdt straight up. Just 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 curve of radn37o8aruk ie:4*stlgg1(5ve8ie uu x ius $r$ 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 al)xtux/wf s, n) h11lot a constant speed v. Then it goes around the same curve,)o)tx1x/1slf n hlw u 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 const:y7dwv nec,mbn 11 x.dant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centr7nwnexc,11bmy: v .d dipetal force on the car as it goes around the second curve, compared to the first?

  A car of mass m goes around a b/nteqj6 x/6 -z wmihkd ulu206anked curve of radius r with speed v. If the road is f/um wnzikl6exhd6-uq 20 6tj/rictionless due to ice, the 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 curvesn)-k7ds7nwm-5a nd jg on a 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) jda)5sgn -nkwn77d m -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 Olympic bobsled track is not constant, vqu 9qq-4 y1six9 *usu0t a/svbut increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally "climb th i* xq uvsqy/4v-su9 a1q0ust9e 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 h w7nkf7ad 6osqqx9 x+od-:1t ,ybhaq)ave both centripetal anonq-da7s1ak7 9ox+bqwfy: )hdt x6, qd tangential acceleration?

  The gravitational force betw4nla;jd3zy x)w3k2pn een two objects is proportional to

  The gravitational force between two objects is inversely proportional tos3e u i./tmqa l.)1kzb

  Two objects attract each other gravitationally. If the distanclm1zbdx1t;, x 5.sk ome between their centers is cut;xok,bl1z 5xm 1s.dtm in half, the gravitational force

  Two objects, with massem1ly5 wz,,f0 w5vbit*7qav f vs $m_{1}$ 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 mass r ab,op5p1kp9es $m_{1}$ 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 )dqxkc s+5uk5 gravitation.

  Compared to its mass :qopasb7t i/w; ihe3q ,w2p5q on the Earth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixlb 4y;ay29pdq i2 ( x5f uzsj/ae5j0bnth what it is on Earth. An obj j09ajb2a x (24p;n yfu5yeis5lz/dbqect of mass
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from the Earth's surfaca-/lx/wsx n vm;0kmv g/,pu0me, the rocket's weight

  A spaceship is traveling to the Moon. Atyn9owx j bu +.;mfz65s what point is it beyond the pull of Earth's ybjmu+.5fx6n s;w9zogravity?

  Suppose a satellite were orbiting the Ear(mx/4 t+4wijb c r21fjsl v/twth just above the surface. What is its centripetal acceleratiol4wvit/(x2m+ /w1cjs t4 jbrfn?

  A hypothetical planet has a mass of half that ofd:s g(*t6 uljk the Earth and a radius of twice that of the Earth. What is the acceleration due to gravity on the planet in terms of g, the acceleration due to gravity at the uk6(ld tsj*g:Earth?

  The acceleration of gravity on the Moon is one-si(e;5y uerc(en( 0s hcw tt;xq5xth what it is on Earth. The radius of the Moon is one-fourth that of the Earth. (w;s;t0(n5ex(qyrhe c t ec5uWhat is the Moon's mass compared to the Earth's?

  Two planets have the same surface gravity,r8-.sd wgq 2d ir.3wb 9n3croh6 vl:sg but planet B has twice the radius of planet A. If planet A has ql.38w:r9 h sgbow.rdd-s 62civ3rn gmass m, what is the mass of planet B?

  Two planets have the d)+flodr 7m2i same surface gravity, but planet B has twice the mass of planet A. If planet A has radi d7m+)loi rfd2us r, what is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a g dph o,slq*xf+ry7;9 spherical planet (mass M). Which expression givxfy,q9+7d;rlps*h go es this satellite's orbital velocity?

  Satellite A has twice the mass of sazahv*aevzu+ 0mv q82;b2yv ,itellite B, and rotates in the same orbit. Compare the two satellitezv avze2 u+ayi2q 0h vb8;*,mv's speeds.

  A person is standing on a scale in an elevator accelerating dohq9e kx3uv1n2wnward. Compare the 3qnh x9k 12veureading on the scale to the person's true weight.

  Who was the first person u- 1x(+wds qu3okp+tq to realize that the planets move in elliptical paths around t d+upw1uo+3ksqt-x(q he Sun?

  The speed of Halley's Comet, while traveling in its elliptical on;g2q1l y ,yk;c3lul r*q 1j-z(ostghrbit around the Sun,*gn1 1lq;g, (jh;ks cr qlu o23lt-yyz

  Let the average orbital radius of a planet be R. Let the qh)i;)bzq h(aj, d h:sorbital period be T. What quantity is cons:bh szi;h) (q daq,hj)tant for all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxa5wrx ,wfe, ,*c l)ow a-5xcszy 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 of revolution of that new pleczx )l s o*w,- wc,5,5faraxwanet be, compared to the Earth's orbital period?

  The average distance from the Earth to the Sun iobm n.wg5/3mh g f1tu1s defined as one "astronomical unit" (AU). An asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?fbgt13/wmonm .g u5h1

State Kepler's laws. v s,w 7tqddu5x*2uux+

  List the four fundamental forces in naturexks-7,t pc 0 l3vaw;yz.

  An object moves with a constant speed of 3+to , ;;sox ;r 6ggubj+j)okel0 m/s on a circular track of radius 150 m. What is the accelero jo ubr;j6)s+;,oxe + ggk;ltation of the object?

  The maximum speed around a level curv.ubv 0v.q2 xnke is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors rq.xb20unkv. vemain unchanged.)

  What is the centripetal acceleration of a point on the per*voikc l1 vs8+imeter of a bicycle wheel of diameter 70 cm when the bike cvls o*i v+8k1is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 rev/s is located 0.200 m f5zf:)vg6mrh q cx( ws,rom the axis. Whas5cf hw z)mq:r(xv ,g6t is the centripetal acceleration?

  How many revolutionso51u/zak-v ,5xyr8s *f anbs g per minute must a circular, rotating space station of radius 1008* gr /-fs nauy1o5zxs,b5kav0 m rotate to produce an artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes /)oq4zkdogs/b; )wx,-5e x elsjjo2waround a 13.7 m radius turn at 96.5 km/h. What is the centripetal forqs4; kjse/eg) j)2w/l owbx ox- ,dz5oce on the motorcycle?

  A 0.50-kg mass is attached to the end of a 1.0-m stringybw9 : e8bcg7(bhgr+l. The system is whirled in a horizontal circular path. If the maximum tension that the string can withstand is 39b rb7ywe 8:l(+bghgc50 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 and whirled in lm1 q q:tr34ht.pj va8a 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':3q8 rm4q ht .lapj1tvs speed at this point is given by

  A stone, of mass m, is attached to a strong string and whirled in a ve93qrbhs 16bf bzq)7e ertical circle of radius r. At the exact bottom of the path sh17zeb6ebqf3q9b)r 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 ow-tqsf0dg o;s:7qu k-ut of the dive. What is the radius of curvature of the loop in whic d7kg 0:qfqtso- -wsu;h the plane is flying?

  A pilot makes an outside vey a9pbn ;;6sj l ain:o5eag0c).otv:qzz2 . cgrtical loop (in which the center of the loop is beneath him) of radius 3200 m. At tgi.vcz)l::ab6qetyso 05n a.can jop9 ;;2zghe 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 6b* 28n) 1gnonlh:wybb enf(nis the minimum radius of curvature that a jet plane's pilot, pullingygbn nw6l)ebh8b nnon2f1: ( * 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 tn 6c3 uv3a:( 08jjjlup 9irehkhe tires on the verge of slipping. How fast jilvajp:( 3 3hu6rekn908 cju 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 20 m/s. The cenbc3wngl;7d r 6c3 6nlbdg r7w;tripetal force 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 gg: 9+tc2bx.pzr*,duxcty; ,psw7kc.a x 0r yat a speed of 14 m/s. What must be the minimum coefficient of friction between the tires anxp2sg ;ua kw byyptx* rt9z70gc:. c,+. xc,rdd the road for the car to make the turn?

  A car is moving with a c. pw cpxcnrk. x+t9 j(uj;wl54onstant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the minimum radius of the curve if the carp 4.+ xjrpkxc95tlu w.cnj(;w is to stay on the road?

  What minimum banking angle is required for an Olieigrl*o+s ; 4ympic bobsled to negotiate a 100-m radius turn at 3+4io*er s ilg;5 m/s without skidding? (Ignore friction.)

  A horizontal curve on 4a t zbh- ,p wext6*b4d48blqna bobsled 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, banked at an a:rgpd/ -s)vzp:a fj;i basy6.54m dcmngle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 m is bankedwy zf6;8wy2 kp 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 yzwzbgwo88c)n-spf 9 w8f z(- horizontal circle of radius 0.500 zfzyw w (gw8oc)8pbfs9z-8-n
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 n:jv( dba g.:oat a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (onlv.do n j(ab:g:y 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 conib+li1dck 9 9idzux .5sists 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 pe 6zum7avu j2 ct)n(*tzrson standing on the Earth, due to the Moon? The mass of the 7zc)m2n(tuatv6j* uz Moon is $7.36 \times 10^{22} \; kg$ and the distance to the Moon is $3.82 \times 10^{8} \; m$.

  The gravitational attract hg re, (sfo51u7its4qive force between two masses is F. If the masses are moved to hq7t(r4s,e fios 1uh5galf of their initial distance, what is the gravitational attractive force?

  For a spacecraft going from the Earth toward the Sun, at w3,r f-j4ltnu.nzd -sfhat distance from the Earth will the gravitational forces due to the Sun and the Earth ca-fudnzf t-sn3 .,r4 jlncel?
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 kc) cv el0ee0-8oa(dmis $7.4 \times 10^{22} \; kg$ 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 distanbpy6 :87prs yoce above the Earth equal to the radius of the Earth. What is her acceleration due to gravitybp p7:yy8r so6?

  The radius of the Earth is R. At what distance (38 poz*al*eseajpq0above the Earth's surface will the accjoa0*z *(p8e ql3peaseleration of gravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equal 8b136i+ww*e km ll n ;icen:zhto 3 times the radius of Mars. The acceleration of gravity of the satellite, as comparedhi3zniml *k:; e+ c18lw6bnwe to the acceleration of gravity on the surface of Mars, is

  At a distance of 14000 km from some planet's center, the acceleration of gravitp8 *s+he8e w:en s9gm51mmnymy nm5+ehe*8y wpm 9mgsem 8n s1: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 Eartz6g3ste r -o ).3c,bjkdr7 jqbh has radius r. If the object 3gb)rojbkj c,qzre d-6.37 st is raised to a height of 3r above the Earth's surface, what is its weight?

  By how many newtons does the weight of a 100-kir 497jsz q)dqg person change when he goes from sea level to an altitude of 5000 m? (The mean radius of the Earti qrd79zq) sj4h is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of mass 100 kg is ax* 4zn 8cvv5blt a point 3r above the Earth'svzlbx54 nvc*8 surface. What is the satellite's weight?

  A spherically symmetric planet has four 4hx15k xtybt2p2g dj.times the Earth's mass and twice its radius. If a jar of peanut butter weighs 12 N on the surface of g1j bt 4.hx xk2p2d5ytthe Earth, how much would it weigh on the surface of this planet?

  During a lunar eclipse, the Moon1rnr7j7v ls dinql8- 8, Earth, and Sun all lie on the same line, with the Earth between the Moon anrv1 7in8 lj78ndlrq- sd 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 transpo8)k h6-zri jjcrted 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.k hggqp.13q3mzc f 44o, it just skims the surface of the Earth). What is the speed of the satellite? (The mean radius of the 3qm 3c hfp41.qgkgoz4Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in a low circular orbit about the Earth (i.e., it jgp bwtx*,shwdl 96+h,ust skims the surface of the Earth). How long does it take to make one revoluti6+h gwd, xhs,tp lwb*9on around the Earth? (The mean 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. x/yy9i3. kc sw It is observed to have a period os9xy cw.i 3/ykf 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 vew/y(-gw(4 c rtrdd1 $1.34 \times 10^{9} \; m$, and a period of 3.55 days. What is the mass of Jupiter?

  The innermost moon of Jupiter orbits the plzrd qk0aq /2:g4j vfw2anet 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 or4x r;i,(pj(xs v-rm q9jy aj5zbital radius r, and moon B has orbital radius 4r. v;j (x irj5qsr jxm-ypza 4,(9Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter i/ks8adq97w)u a -rmr t)lu fy;s $7.78 \times 10^{11} \; m$ 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 avek:l uz05besr ,rage distance fro:b,5rek0l suzm Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)