1. What is Einstein's Mass-Energy Equivalence?

Definition: The equation \( E = mc^2 \) shows the relationship between mass and energy, where energy (E) equals mass (m) multiplied by the speed of light (c) squared.

Purpose: This fundamental physics equation demonstrates how mass can be converted into energy and vice versa.

2. How Does the Equation Work?

The equation is expressed as:

Where:

• \( E \) — Energy (Joules)
• \( m \) — Mass (kilograms)
• \( c \) — Speed of light in vacuum (299,792,458 m/s)

Explanation: A small amount of mass can be converted into a tremendous amount of energy due to the speed of light being squared in the equation.

3. Importance of the Equation

Details: This equation revolutionized physics by showing the equivalence of mass and energy, forming the basis of nuclear energy and our understanding of the universe.

4. Using the Calculator

Tips: Enter the mass in kilograms and the speed of light (default 299,792,458 m/s). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the speed of light squared in the equation?
A: The squaring accounts for the immense energy contained within mass, as energy is proportional to the square of the speed of light.

Q2: What's the practical application of this equation?
A: It explains nuclear reactions, helps calculate energy in particle physics, and is fundamental to understanding cosmology.

Q3: Can I change the speed of light value?
A: While the speed of light in vacuum is constant, you might adjust it for educational purposes or to see how changes would affect energy.

Q4: How much energy is in 1 kg of mass?
A: Approximately 89,875,517,873,681,764 joules (about 21.5 megatons of TNT equivalent).

Q5: Does this equation work for all types of energy?
A: It specifically describes the rest energy inherent in mass, not other forms of energy like kinetic or potential energy.