Question

Little Pig's House:

- The walls are made of 10-cm thick bricks, insulated with 5 cm of fibreglass. They cover a total area of 45 m2.
- The floor is thick and well insulated.
- The 15-m2 roof is made out of ceramic tiles that are 2.5 cm thick and insulated with 5-cm thick fibreglass.
- The door is 3.5-cm thick solid wood with an area of 2.0 m2.
- There are double-paned windows with a combined area of 4.0 m2. Each window is identical, having two 3-mm thick glass panes with a 2-mm air gap between the panes.
- An electric heater heats the house’s interior. The pigs themselves contribute in heating via metabolic power (each pig contributes ?meta=100 W).

Assuming that each pig contributes 100 W of metabolic power,
calculate the power required from the heater to maintain the inside
temperature at 20 ∘C, when the outside temperature is 8.5 ∘C.
**Give your answer in W.**

Answer #1

A house has well-insulated walls 15.0 cm thick (assume
conductivity of air) and area 500 m2 , a roof of wood 5.0 cm thick
and area 270 m2 , and uncovered windows 0.55 cm thick and total
area 30 m2 .
I don't need help with question A, I got it right but i don't
know how to do b and c
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