Final answer:
b) Light speed. In the equation E = mc², the 'c' refers to the speed of light in a vacuum. The correct answer is
Step-by-step explanation:
The "c" in the equation E = mc² refers to the speed of light in a vacuum, which is approximately 3 x 10⁸ meters per second. This equation, formulated by Albert Einstein as part of the theory of special relativity, shows that energy (E) is equal to the mass (m) of an object multiplied by the square of the speed of light (c²).
This reveals the principle that mass can be converted into energy and vice versa, which is a crucial concept in physics. Taking the letter options provided, the correct answer is b) Light speed.
In the equation E = mc², the 'c' refers to the speed of light. This equation, derived from Einstein's theory of relativity, relates energy (E) to mass (m) and the speed of light (c). It shows that energy and mass are interchangeable, and that matter can be converted into energy and vice versa.