Understanding E=mc²
Einstein's famous equation, E=mc², revolutionized physics by showing that mass and energy are fundamentally the same thing in different forms. The equation tells us that energy (E) equals mass (m) times the speed of light (c) squared.
The Formula
[\text{Energy (E)} = \text{mass (m)} \times c^2]
Where c = 299,792,458 m/s (the speed of light in a vacuum)
Example Calculation
Let's calculate the energy equivalent of a 2 kg object:
Step-by-Step Calculation:
- First, measure the mass: Mass = 2 kg
- Next, use the speed of light squared:
(299,792,458 m/s)² = 8.98755179 × 10¹⁶ (m²/s²) - Finally, multiply them together:
Energy = 2 kg × 8.98755179 × 10¹⁶ m²/s²
This results in: Energy = 1.79751036 × 10¹⁷ Joules (J)
So, that 2 kg object contains approximately 1.79751036 × 10¹⁷ Joules of energy!
Putting This in Perspective
To understand how much energy this is:
- 1.8 × 10¹⁷ Joules is roughly equivalent to the energy released by 43 megatons of TNT
- This is more than twice the energy of the largest nuclear weapon ever tested
- It could power an average U.S. household for over 4 million years
This demonstrates why nuclear reactions, which convert just a tiny fraction of mass to energy, can be so powerful.