Graphics Programs Reference
In-Depth Information
5.
a
r
T
T
A wirecarrying an electriccurrent issurrounded by rubberinsulation of outer
radius r . The resistance of the wire generates heat, which isconducted through
the insulation and convectedinto the surrounding air. The temperature of the
wirecan be shown to be
ln( r
q
2
/
a )
1
hr
T
=
+
+
T
π
k
where
q
=
rate of heat generation in wire
=
50 W/m
a
=
radiusofwire
=
5mm
k
=
thermalconductivity of rubber
=
0
.
16 W/m
·
K
20 W/m 2
h
=
convectiveheat-transfer coefficient
=
·
K
T =
ambienttemperature
=
280K
Find r that minimizes T .
6.
Minimize the function
1) 2
1) 2
F ( x
,
y )
=
( x
+
( y
subject to the constraints x
+
y
1 and x
0
.
6.
7.
Find the minimum of the function
6 x 2
y 3
F ( x
,
y )
=
+
+
xy
0. Verify the result analytically.
8. SolveProb. 7 if the constraint ischanged to y
in y
≥−
2.
x 2 .
9.
Determine the smallest distance from the point(1
,
2) to the parabola y
=
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