Is it possible for an object moving wig frdq5qk 0:y/th a constant speed to accelerate? Explaind5g rkqy0/ fq:.

  Consider a particle moving with constant speed such that its acceleration of co kj/vxy 254 mmy3fow0onstant magnitude is always perpendicul/53 y2mxjov0ko 4fwmy ar to its velocity.

  An object moves in a circular d3yvboff* ) /kpath at a constant speed. Compare the direction of the object's veloci y bf3o*vd)kf/ty and acceleration vectors.

  When an object experiences uniform circulampdzch+s*zz:4art9q w a*s 4. r motion, the direction of the acceleraq w+4cmzrt* .p*:ds9 zaazhs 4tion is

  Consider a particle moving wil-z6cl etwbon ;*o,j3b/6uyi th constant speed such that its acceleration of constant magnitude is always perpendicular to its ve- ,l;6oneclbtw3z6y/u ibo*j locity.

  What type of accelerafi 7uja- 0ec ,rdqm 09x/obrs8tion does an object moving with constant speed in a circulaf80eor7dj- rsa0cm uxq 9/ib,r path experience?

  What force is needed to mak*1doh pm3tw nnmhv1 om(4o4 v1,oaai0e an object move in a circle?

  When an object experiences uniform circular motion, the direction 5vx,o1ceka av;4*lluof the net forvx;ol 5* c4av, 1laukece is

  A roller coaster car is on a track that forms a circular loop in )d,30-,x k1 opo1al *thlvr wdygusa9the vertical 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 acceleration at this point?o h)d 1gwrl , 3v ,*1txa09udyp-lsaok

  A roller coaster car (mass = M) is on a track ) sqi89 et5ynhthat forms a circular loop (radius = r) in the vertical plane. If the car is to just manh9t) q is8ey5intain 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 verticamsd /qmc atqj470s7k5zjy,f ca( ; 2ril dive then follows a semi-circular arc until it is going str scraajmziq74 s5k 2mct/yj7d,q ( 0f;aight 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 rad4gjal 7d )by9wius $r$ 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 h,l4md1iomki w- z2u1 constant 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 curve for the second time, compared t1-mii1kdz,mu 2w o4 lho the first time?

  A car goes around a cur2o3ulozhsfyo o zc 2)a/(1)ag ve of radius r at a constant speed v. Then it goes around a curve of radius 3 1h)zoucafyo/as(go2zo )2 l2r at speed 2v. 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 baw i0chuernvn0 :bz :6kr .zx5t3h)ul*nked 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 from the road is: i:ru*)0cb. n l5u0w rvn3k6tehzz hx equal in magnitude to

  Two horizontal curves on a bobsle433wy)rhx35 i gjn zgps fe1+dd 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 smaller radius curve is v. What +4fg deh 133rspwxg j)5n3yziis the safe speed on the larger radius curve?

  The banking angle in a turn on the Olympic bobsled tratsmzr:0+ez(u ck is not constant, but increases upward from the horizz0rezu(s :t+m ontal. Coming around 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 an object moving around a circular path to have both centrihwx)*f8gja w4//yd q zpetal and tangential accel)8h w*y z4af/x /wqgjderation?

  The gravitational forcr flq88en*g)vt xq.:ce between two objects is proportional to

  The gravitational force between t ep)-3ne ls/vjzoju dv5,jj95 wo objects is inversely proportional to

  Two objects attract each other gravitationally. If the distance between their w5br-mj t 99/dp7z+t tifmhz9centers is cut-j m bf/h9z d5r ztw7tmt9+p9i in half, the gravitational force

  Two objects, with massestb9oh:3y;rw8 a df8k 8 nfh0-b2sjole $m_{1}$ 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 massee6 7b p(07o hln8qxgwvs $m_{1}$ 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 univer2peadv n 4p80x/ac a0cd8htz 4sal gravitation.

  Compared to its mass on the Earkq ifl(t*;es .:ws t:qth, the mass of an object on the Moon is

  The acceleration of gravity on the Moon is one-sixh0fh 5hkibhnus ,9s 8,th what it is on Earth. An object of mashh08,nh sfu b9hi5sk,s
72 kg is taken to the Moon. What is its mass there?

  As a rocket moves away from un)m 3ga8 e9s(s7-uguan1ody43rvfq the Earth's surface, the rocket's weight

  A spaceship is traveling to the Moon. At what point is it 8ol )yzc;p7j vbeyond the pull of Earth's g )opyl78zcj v;ravity?

  Suppose a satellite were orbiting the Earth just above the surface. What is itsazlkw xh 1v2bz6e9wv7osi+nr(l (; 2t ce29osi ;tlwlb6zvv1ek7(+n zwr(2 h xa ntripetal acceleration?

  A hypothetical planet has a mass of half that of theu nb /33qo+.mz- nenfs 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 theu.e3szmb-n/n q+n3o f Earth?

  The acceleration of gravity on the Moon is one-sixth what it is on Earth. T/9 spxivn p)hp udc*f;vge28:he radius of the Moon is one-fourth that of the Earth. What is the Moon's mp/x*vsp2 hgc9e8ndip;): ufv ass compared to the Earth's?

  Two planets have the same surface gravity, but planet B has twice g,.qj 8m cy287dlwat lg2zqq0pr2/i x the radius of planet A. If planet ,7ad2wptx y 8g 2i8/02lqrl.gc jqqmzA has mass m, what is the mass of planet B?

  Two planets have the same surface gravity, but planet B has twice the mass :a v5aocrv k lo24l)-sof planet A. If planet A has radius r, wlro:5-cs2 a4vov)k alhat is the radius of planet B?

  Consider a small satellite moving in a circular orbit (radius r) about a sphpm j)rf.x+b,mq63ek a5 ,r8ok*e yngperical +ag)63omfq85p.ye * k,bpmjxrrk,ne planet (mass M). Which expression gives this satellite's orbital velocity?

  Satellite A has twice the mass of satellite B, and rotates in the salxj- 3epbd: o-sf. wee,0ns w7me orbit. Compare-bl0.7pe x noe:s,-3 dewsfjw the two satellite's speeds.

  A person is standing on a scale in an elevator accel/2ki pu-izzm :erating downward. Compare the reading on the scz m/-iipu 2k:zale to the person's true weight.

  Who was the first person to realize that the planets move in elliptic :2 vdz1) qs-eso2eigmal paths aro2miq ed1 zv:o 2sg-)esund the Sun?

  The speed of Halley's Comuvr3f7ekw 39nv t2g)j.v2 ojngz8t -d i95bsget, while traveling in its elliptical orbit around the Sun,v ov)8 sk 7.viwjgdgnejr593-2 gn 9 bft3utz2

  Let the average orbital radius of a planet be R. Let the orbital period be T.(f5i ellh4si 3lbt *w4 What quantity is constant fil w stb(44i hf35ell*or all planets orbiting the Sun?

  A planet is discovered to orbit around a star in the galaxy Andromeda, with the 5uo9i b3 mb-aosame orbital diameter as the Earth around our Sun. If that star - u iom5ao9b3bhas 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 "astronomicaltmmvh/frj )nhi uwh 0938c71radt )+i9s ayl/ unit" (AU). An a3c)/)td y0 1vm9lusi8j mfh /tr9hr+ a hniw7asteroid orbits the Sun in one-third of a year. What is the asteroid's average distance from the Sun?

State Kepler's laws.enosx 1(mtjf: l 8y-mbrnz9c/ mv:h(s1e,1r l

  List the four fundamental forcglpvkets yjm/welp)/:l*3 4-es in nature.

  An object moves with a constant speee8ga c l03(a.kmka,ucd of 30 m/s on a circular track of radius 150 m. What is the accu3kecma.a (,8 k cg0laeleration of the object?

  The maximum speed around a level curve is 30.0 k -2u cjwr-xv85kbaqf)h :(glrm/h. What is the maximum speed around a curve with twice the radius? (Assume allr-5hl (vk :2 jarwux-g8)qbcf other factors remain unchanged.)

  What is the centripetal acceleration of a point on the perimet 6iqf1 n3av hmo*et:h*er of a bicycle wheel of diameter 70 cm when the bi:3hn6hi*tm f vaq*oe 1ke is moving 8.0 m/s?

  A point on a wheel rotating at 5.00 ;no t;w-sur.(e4 )odvrch8bg rev/s is located 0.200 m from the axis. What is the cen( rbs-eh)durt.c4o;vgn wo ;8 tripetal acceleration?

  How many revolutions per minute must a circular, rotating space station of radiunvt:1tod 28ejbhs5y4s 1000 m rotate to produce a15 t428: jbdev oynshtn artificial gravity of $9.80 \; m/s^2$?

  A motorcycle has a mass of 250 kg. It goes around a 13.7 m ranq,r8sx:hsv.iez3 yb1l v62ddius turn at 96.5 km/h3bl 2,evxh zq61idry vn. :8ss. What is the centripetal force on the motorcycle?

  A 0.50-kg mass is attached 4w0usl( v9uovp 9(3sry dqndv(pa xnw w9-l-3to the end 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 350udwwn( 9ow-(9ad(3r y 9uns0s3vvvpx q4l-p l 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 a vertic*9e gk ;mwhil*tzrg 10al 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 i1*kt*0hgz;gl9emw r given by

  A stone, of mass m, is attached to a strong string and whirle(s4qt1uw4dm3 k99xww kl *ejud in a vertical circle of radius r. At the exact bottom of the path the tension in the striksu 3mq wxetu*dj 19l4w(4kw9 ng 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 ofz-q44skbfx n (h 3bb(n 4g when pulling out of the dive. What is the radius of curvature of the loop in whichbnksbx(q(- 4zb3f n4 h the plane is flying?

  A pilot makes an outah xe;a+ b4h,b1 (pa ar8rh+ehside vertical loop (in which the center of the loop is beneath him) of radius 3200 m. At the top of his loop he is pushing down on his seat with only one-half of8hxha+a b+pe arh1rb,4( ;eha his normal weight. How fast is he going?

  The maximum force a pmc4;f7jivgi whg+r06ob c 00qilot can 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 dive, can tolerate at a speed of 250 m/s?gh;c mjivc rwb g6070f+io4q0

  A car traveling 20 m/s rounds xo, xjjo/4xuv):zh t1 +3vw xhan 80-m radius horizontal curve with the tires on the verge of slipping. How fast can this car round a second curve of radius 320 m?:xj wx,vjzx +uhotx41hv o/3) (Assume the same coefficient of friction between the car's tires and each road surface.)

  A car is negotiating a flat curve of radius k5bfo bt) zroj 70;2f2gssud/ 50 m with a speed of 20 m/s. The centripetal force provided by friction is gd0 kf5ju)bzoobs ;2 72fsrt/$1.2 \times 10^{4} \; N$. What is the mass of the car?

  A car goes around a flat curve of radius 50 dc2wi m8, zaa02iphm.m at a speed of 14 m/s. What must be the minimum coefficient of friction between the tires and the road i2 mc8zaa2iw.h0 ,m dpfor the car to make the turn?

  A car is moving with a co h9dzsxw) 0d1v x6st8w,dswb2nstant speed v around a level curve. The coefficient of friction between the tires and the road is 0.40. What is the miniddws dvb082 9w1)wzsh6,xx s tmum radius of the curve if the car is to stay on the road?

  What minimum banking angle is required for an Ol ju0op5 i335-vx.x9bokb i azjab*b 9tympic bobsled to negotiate a 100-m radius turn at 35 m/s wi3xk xj5bt* u90o a z.opjbb abi-593vithout skidding? (Ignore friction.)

  A horizontal curve on a bobsled run is c 3wia gv/a2z+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 r6e )t m xe2d7u9htmgj2adius 100 m, banked at an angle of $45^{\circ}$, may be safely negotiated at a speed of

  A curve of radius 80 3x;vtl -a+a eu.jw( kym 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 ex szm,r f, x3oh*ag 3;5hvnpb3nd of a string is revolving uniformly in a horizontal circle of ;fv,axn 3p 35bx h3o ,rzmhsg*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 cy wglcd: d;c7bvdv6i:9f9g b kn6 h06xar accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in nucyi9l ddc g:f:xkv6g6b;9hnvb 6 d0 w7merical 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 orq(sy zi;z d bp,g.y,k;l71jk f 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 standing on w 8wh 1tk/*tgfthe Earth, due to the Moon? The mtf/tg*k 1w8 hwass 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 F. byxtc2 -fi5zwh(m.xh 1h)8jl If the masses are moved to half of their initial distance, what is the gravhi-j )bfthxl2.z1w 8m5x (yh citational attractive force?

  For a spacecraft going from the Earth toward g9hp xp6m*f/sthe Sun, at what distance from the Earth will the gravitationa*fx/mhgp 6 sp9l 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 isqb779 jg4r-*o di kvb iki9d1g $7.4 \times 10^{22} \; kg$ 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 vz t342q*lehv"space-walk" at a distance above the Earth equal to the radius of the Earth. What is her acclzv*2t v3 heq4eleration due to gravity?

  The radius of the Earth is R. At what distance abq 0j(b r4kcjd yuaas664lsq65 ove the Earth's surface will the acceleration of grs 06aqus4 j(qa kbj5664d lycravity be $4.9 \; m/s^2$?

  A satellite encircles Mars at a distance above its surface equacvjfo- ):r)en l to 3 times the radius of Mars. The accelerac: v-n)e)rj fotion 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 centec68m5j sch (d ej-1xw,h1zntjr, the acceleration of gravity 1d -chj8nsw6m1x(hj z5 tej, cis $32 \; m/s^2$. 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 iuk /r:e:xog+0n,p u 68p.zp.ft pyacEarth. The Earth has radius r. If the object is raised to a height of 3r above the Earth's surface.c/i :zp.rf8ga0u:e 6utkxp npop+y,, what is its weight?

  By how many newtons dluk2a(e t0m z7oes the weight of a 100-kg person change when he goes from uae mtkl(0 z72sea level to an altitude of 5000 m? (The mean radius of the Earth is $6.38 \times 10^{6} \; m$.)

  The Earth has radius r. A satellite of ma:ieh+y8v 5xf k 2ihlor26g/ fkss 100 kg is at a point 3r above the Earth's surface. What is the satellite's i5+ rilkv o2:8fx ke6/fg2h yhweight?

  A spherically symmetric planet has four times the Earth's mass and twizy4ayv; bq. 6bce its radius. If a jar of peanut butter weighs 12 N on the surface of the Earth, how much would it weigh on the sur.v6 ;ybzqby 4aface of this planet?

  During a lunar eclipse, the Moon, Earth, and Sun all lie o o4m t3c1cys (px;-vwcn the same line, with the Earth between thesx-1cywpcv (;mo3t4c 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 tr )v y+oktbrr66ansported 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., it just wu/sdg19 7ta1ck a+ l, bxdqs+skims the surface of the Earth). What is the speed of the satellite? (The mean b ksad/1t1au cx,9+dqwg+7ls 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 jusd gc) j)3rmr. u3arxu.t skims the surface of the Earth). How long does it take to make one revolution around the Earth? (The mean radius ou)d 3.u3gmcr .a xjrr)f the Earth is $6.38 \times 10^{6} \; m$.)

  A satellite is in circular orbit 230 uan(on,/ pqwmt* 5 z2nkm above the surface of the Earth. It is observed to have a period of 8nozq*um 52p,/wnnta (9 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 af;,hjewse 0y:i1y pq*n 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 orqwm*p0cnr,ppzd- ms .9 g uxy*z(09drbits the 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 ht las k-81zwmxf546dr l.jjsr )9kb-s1w*q pcas orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to compq6 bt1d5s w-zkcrp.9 )-aswx48jlk*f jr1 msllete one orbit. How long does it take moon B to complete an orbit?

  The planet Jupiter is bq mzlf nq1yp0 c+3 9rjcos1(+kxd99r $7.78 \times 10^{11} \; m$ 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 hmn;bp * *7hp:rx0 cnhthe Sun once. What is the average dnb*mhpcp 07;h:h* x rnistance from Jupiter to the Sun? (The distance from the Earth to the Sun is $1.5 \times 10^{11} \; m$.)