If with steady-state heat flow established, you double the thickness of a wall built from solid uniform material, the rate of heat loss for a given temperature difference across the thickness will:

a) become 1/ 2 of its original value.
b) become one-half of its original value.
c) become four times its original value.
d) also double.
e) become one-fourth of its original value.

A) Become 1/ 2 of its original value.

B) Become one-half of its original value.

Explanation:

As we know that heat transfer trough the wall of thickness t given as

Where

K=Thermal conductivity of the wall

A= Cross sectional area of the wall

t=Thickness of the wall

ΔT=temperature difference across the wall surfaces.

When the thickness become double ,lets sat t' = 2 t

Then new heat transfer

Therefore the new heat transfer become half of the original.

4

explanation:

4

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.