# More energy in bullets or batteries

• Fezziwig

#### Fezziwig

Are there more joules in a bullet or a battery (in it's lifetime). I'm afraid I don't know bullet calibres but we can assume that we're talking about an AA Battery.

Fezz: You related to the guy on 'That '70's show??'..Wilmer??

Anyway, why not figure it out?

the energy of a bullet is it's kinetic energy 1/2mv2

so pick some caliber and some speed...

and the energy of a battery, watt hours...
conversion: to convert joules to watt hours, multiply by 2.78 x 10-4

the usual standard for battery power is:
The capacity printed on a battery is usually the product of 20 hours multiplied by the constant current that a new battery can supply for 20 hours at 68 F° (20 C°), down to a specified terminal voltage per cell. A battery rated at 100 A·h will deliver 5 A over a 20-hour period at room temperature.
http://en.wikipedia.org/wiki/Battery_power#Battery_capacity_and_discharging

A typical dry cell battery can be discharged only once; a rechargable battery many times and if that is what you want to compare, you'll need to find it's life cycle characteristic...
how many times it can be discharged and recharged or it's lifetime power capability...