# Having trouble with problem

1. Sep 6, 2004

### fishboy39

I have a physics problem that I am stuck on: Approximately 4 x 10^9 kg of matter is converted into energy each second in the sun. Find the power output of the sun. I know the answer is 3.6 x 10^26 W I just can't figure out how to get the correct equation and numbers. Any help would be appreciated. Thanks

2. Sep 6, 2004

### Tide

The relevant equation is
$$E = mc^2$$

3. Sep 6, 2004

### geometer

Use [ tex ] E = mc^2 [ /tex] to convert the mass to energy, then power is just energy per unit time.

4. Sep 6, 2004

### fishboy39

Thanks! I knew it was something easy!

5. Sep 6, 2004

### daveed

...why not e=mc^2?

6. Sep 6, 2004

### daveed

LOL sorry must've left the window on too long... haha

7. Sep 6, 2004

### Leong

$$e=mc^2$$
$$P=\frac{\Delta e}{\Delta t}=\frac{\Delta mc^2}{\Delta t}$$
Given $$\frac{\Delta m}{\Delta t}= 4*10^9 kg/s$$
$$c=3.00*10^8 m/s$$

8. Sep 7, 2004

### Galileo

This reminds me of a lecture my (lively) optics professor gave.
He asked us to just imagine four billion kilograms of matter being
converted every second. :surprised
"Suppose you would throw 700 g brick up into outer space every second. (he freely demonstrates what it would be like).
Now imagine all the people in the world doing that." It's amazing