Solve Heat Transfer Question: Find Rate of Heat Loss from 700m^2 Ceiling

[Studious_stud]

Homework Statement

The 700m^2 ceiling of a building has a thermal resistance of 0.2 m^2K/W. Find the rate at which heat is lost through this ceiling when the ambient temperature is -10C and the interior is 20C.

Homework Equations

Newton's law of cooling:

Q=hA(Ts - Tinfinity)

The Attempt at a Solution

Ts = 20C
Tinfinity = -10C
A = 700m^2


Anyone want to help me out with this one? Would be greatly appreciated!

 

[kreil]

Newton's law of cooling is,

$$\frac{dQ}{dt} = A h (T_{env}-T(t) )= Ah \Delta T$$

where:

Q is the thermal energy in joules
A is the surface area of the heat being transferred
h is the heat transfer coefficient
T_env is the temperature of the environment
T(t) is the temperature of the objects surface and interior

You have all these numbers given, now just plug them in!

Note: The heat transfer coefficient has SI units in watts per meter squared-kelvin, i.e. the heat transfer coefficient is the inverse of thermal insulance.