# Homework Help: EM waves and blackbody radiation question

1. Nov 28, 2012

1. The problem statement, all variables and given/known data
A rectangular metal plate measures 0.20 m long and 0.3 m wide. The plate is heated to a temperature of 1,433 K by passing a current through it. Assuming that it behaves like a blackbody, how much power does the plate radiate under these conditions?

2. Relevant equations
P∝T^4 (power is proportional to the temperature raised to the fourth power)
Only relevant equation I can find in my text book so far. I don't where to factor in the lengths in the question.

3. The attempt at a solution
Ive tried all sorts of combos of the equation i gave, but all of them are wrong. I have the same question with different numbers and the answer to that one but still dont know how to get it.ψ

2. Nov 28, 2012

### norhh

Ok you might not heard about stefan boltzman law
P=σAT4.(where A is surface area)
Where σ is called stefan boltzman constant its value is 5.670373(21)×10−8 W m−2 K−4.
Now find it it is easy.