Discussion in 'Science and Technology' started by Lt. Uhura-Brown, Jul 18, 2013.

1. ### Lt. Uhura-BrownLieutenant CommanderRed Shirt

Joined:
May 14, 2013
Location:
New Zealand
I was thinking about the famous equation E=mc² the other day, when I realised I didn't actually understand it, or rather, the units used.

It seems to me that Joules = (volume multiplied by density) multiplied by (300 million meters divided by 1 second) multiplied by (300 million meters divided by 1 second)?

I know there's something I must be missing, but I can't wrap my head around how it all fits together.

Joined:
Mar 15, 2001
Mass is a basic quantity that doesn't have to be broken down; kilograms are generally the preferred unit. A joule is a newton-meter, and a newton is a kilogram-meter per second squared; so that means joules are (kg x m/s^2) x m = kg x m^2/s^2 = kg x (m/s)^2, which is mass (kg) times velocity (m/s) squared, with the velocity being the speed of light.

So a mass of 1 kg, if converted to energy, would come out to 1 kg x (3 x 10^8 m/s)^2 = 9 x 10^16 J.