1. Oct 25, 2004

### andrew410

At high noon, the Sun delivers 1,000 W to each square meter of a blacktop road. If the hot asphalt loses energy only by radiation, what is its equilibrium temperature?

I know the formula for energy rate of radiation:
$$P = \sigma A e T^4$$
I don't know how to apply this to the problem...
Any help would be great! Thx in advance ! :)

2. Oct 25, 2004

### Tide

If the blacktop is in thermal or radiative equilibrium it radiates the same amount of energy it absorbs.

3. Oct 25, 2004

### andrew410

So do I solve for T for the above formula and plug in the values? If so, then what is the emissivity(e)?

4. Oct 25, 2004

### Tide

e = 1 for an ideal radiator.

5. Oct 25, 2004

### andrew410

thanks a lot!!! :)