e=mc**2 What is the unit of energy?

Question

When we use the equation e=mc**2 to calculate the energy of an atomic reaction. Let's say if one gram of matter is used up. So the numbers would be:

e= 1 x 3 x 10**8 x 3 x 10**8
= 9 x 10**16 gm meter**2/sec**2

Pardon my ignorance. What is this unit of energy called?

Also how would that convert to the English units.

thanks

rm

Answer 1

Well, if you convert grams to kilograms, then you have

e [=] kg*(m^2/s^2) [=] kg*(m/s^2)*m [=] N*m [=] J

However, the units of E are determined by the units of mass, distance, and time that you use, and consequently could by in any of the units of energy.

I'm not sure what english units you mean, but 1 J = .73 feet*pound_force.

For unit conversions, consider using google or download a more comprehensive freeware unit converter, like Uconeer. I use Uconeer for the more obscure unit transformations, and tabulated values for more common conversions. Google it.

Answer 2

The dimensions of energy are usually given in the MKS sytem of units which is Energy=kilograms x meter^2 / seconds ^2.
The Unit is called the joule in honor of the scientist who discovered the mechanical equivalent to heat energys.
The formula represents the Energy inherent to a mass to bind it together.

Answer 3

I think the standard unit of energy is the joule (J)