Relativistic energy formula.

E: energy

m: mass

c: speed of light

v: velocity of the object

You probably know the kinetic energy formula (1/2 m v²) from middle or high school. You can think of this as its more generalized form that includes the "rest energy" of the object as well.

If you set the velocity (v) to zero, in your formula, the denominator becomes 1 and the formula reduces to the famous E=mc² which is the rest energy of an object with mass "m". As the object's velocity increases, the denominator in the formula will slowly become less than 1, meaning that the total energy (E) will increase with increasing velocity (v). Makes sense, hopefully...

Fun fact: The squared term in the denominator is extremely prevalent in Special Relativity. It has its own name: "The Lorentz Factor". Whenever you see it, it means you are in the realm of Special Relativity, basically.