PHYS201
Winter2010
RecitationProblems(Week1)
All problemstakentrom University
Physics,Youngand Freedman,
12thEd.
13.49A 1.80-kgconnecting
rodfroma carengineis
pivotedabouta horizontal
knifeedgeas shownin the
picture.Thecenterof gravityof the rodwas locatedby
balancing
and is 0.200m fromthe pivot.Whenthe rod is
setintosmall-amplitude
oscillation,
it makes100complete
swingsin 120s. Calculate
the momentof inertiaof the
rodaboutthe rotationaxisthroughthe pivot.
tY|,:r:w
{=
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13.58A 50.09hard-boiled
eggmoveson the endof a springwithforceconstant
k=
25.0N/m. lts initialdisplacement
is 0.300m. A dampingforceFx= -bvxactson the
egg,andthe amplitude
of the motiondecreases
to 0.100m in 5.00s. Calculate
the
magnitude
of the dampingconstantb.
L ,
!y#} = A UG'rouht
Sol*/t*. & *{*,*7s{}lo.^a-r< au.;//^th-r ;E
..,,.1r
r/} i
i
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it
at
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13.61A sinusoidally
varyingdrivingforceis appliedto a dampedharmonic
oscillator.
(a)Whatarethe unitsof the dampingconstantb ? (b) Showthatthe quantity/1tm; has
the sameunitsas b . (c) In termsol Fraxandk, whatis the amplitude
for aa = t/(kI m')
=
=O.4rl1Xm\
(i)
when b 0.2{(km)and(ii)b
Z
(qua"rlat o6: n*/r*
Tle
t0
/
t
f nX I b x
& * Jr,oe-a,dr*'ptf
, Ir, { {/) . ln #r: r^x, ftt\
ri.
oonf($*
'4arpna''p'e
anpakr
it :;to*sst/*lu;#
( '
= ( s lul {') 'fr* grrn ,ork^/
}
f'{i
tn".f
-i*'
'n
du*u.rl.{;tqt"'r/
,
*4
5a
ttl
t's
fro
'i
'
a) mi:,1,t,
u^.1{{{\t drt tn Ne*&*s, s0 {'x 't
' xbf, ';f '
l*q ,, ,1/*1 6'" "ry;'t
collideswiththe stationary
lowerball,andsticksto it. The
stringsareboth50.0cm long.Theupperballhasmass
2.00kg,andit is initially
10.0cm higherthanthe lowerball,
whichhasmass3.00kg. Findthefrequency
andmaximum
angulardisplacement
of the motionafterthe collision.
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,
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t d
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& " ' t* i t i t t } , tu ( *n
nd
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} " , tu Aco s{ wl} b 7al.^i*"
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