Answer:
Engineers are a very beneficial contribution in which offers great solutions to national problems.
Answer:
a)R= sqrt( wt³/12wt)
b)R=sqrt(tw³/12wt)
c)R= sqrt ( wt³/12xcos45xwt)
Explanation:
Thickness = t
Width = w
Length od diagonal =sqrt (t² +w²)
Area of raectangle = A= tW
Radius of gyration= r= sqrt( I/A)
a)
Moment of inertia in the direction of thickness I = w t³/12
R= sqrt( wt³/12wt)
b)
Moment of inertia in the direction of width I = t w³/12
R=sqrt(tw³/12wt)
c)
Moment of inertia in the direction of diagonal I= (w t³/12)cos 45=( wt³/12)x 1/sqrt (2)
R= sqrt ( wt³/12xcos45xwt)
Answer:
Tso = 28.15°C
Explanation:
given data
t2 = 21 mm
ki = 0.026 W/m K
t1 = 9 mm
kp = 180 W/m K
length of the roof is L = 13 m
net solar radiation into the roof = 107 W/m²
temperature of the inner surface Ts,i = -4°C
air temperature is T[infinity] = 29°C
convective heat transfer coefficient h = 47 W/m² K
solution
As when energy on the outer surface at roof of a refrigerated truck that is balance as
Q =
.....................1
Q =
.....................2
now we compare both equation 1 and 2 and put here value
solve it and we get
Tso = 28.153113
so Tso = 28.15°C