# Math Help - calculate rate?

1. ## calculate rate?

An X-ray tube operating at 65kV has a tube current of 120mA. The tube produces X-ray with an efficiency of 0.8%

calculate the rate of heat production in the anode

rate = ?

2. The only formula I know for this is the one for Heat Units Per Second, or how much electrical energy is converted to heat in a second... The formula is:

$Heat = kV_p*mA$

So:

$Heat = 65*120$

$Heat = 7800 \frac{HU}{s}$ (HU = Heat Units)

Here's a nifty Conversion Factor:

$HU = 1.4 J$