Calculating Power Dissipated in 20 Ohm Resistor: I = 12 sin(250t)

[jesuslovesu]

Homework Statement

An electric current described by I = 12 sin(250t) flows through a 20 ohm resistor. Calculate the power dissipated as heat.

Homework Equations

V=IR
P=IV
P = I^2*R

The Attempt at a Solution

Using the last equation, P = I^2*R
P = 2880 sin^2(250t)
Is that the best answer I can give? The question gives no information about efficency so I'm not sure if I'm forgetting an equation or something. It doesn't give a value for time either.

 

[Mindscrape]

I think you misinterpreted the problem. The problem asks for the power dissipated as heat, not the power in the element.

 

[Mentz114]

You need to integrate over a time period then divide by the period to get the root mean square (rms) value.