Boltzman Constant, Emissivity and Surface Area of a filament

[kavamo]

Homework Statement

A tungsten filament in a lamp is heated to a temperature of 2.30 x 10^3 K by an electric current. The tungsten has an emissivity of 0.31. What is the surface area of the filament if the lamp delivers 35.0 W of power?

Homework Equations

Stefan's Law

(a greek letter that looks like P?) P(net)=ekAT^4

The Attempt at a Solution

35.0=0.31(5.670x10^-8 w/m^2*K^4)(2.30*10^3)^4A

35.0 = 491876.5257A

35.0/491876.5257=A

7.1156069x10^-5


is this correct?

Thanks in advance for your help.

 

[kavamo]

Problem solved! Thank you.