Compute kinetic energy using Special Relativity
In your physics class, you likely learned that Kinetic Energy is $KE = \frac12mv^2$. While this works for cars and planes, it fails completely when objects move near the speed of light. If Newton were right, you could give an object enough energy to go faster than light. But Einstein discovered that as you go faster, it becomes harder and harder to accelerate further.
The Lorentz Factor ($\gamma$) is the heart of relativity. At normal speeds, $\gamma$ is practically 1. But at 99% of the speed of light, $\gamma$ jumps to over 7. This factor tells you how much the mass of the object has "effectively" increased and how much extra energy you need to add to gain even a tiny bit more speed.
As an object approaches $100\% c$ (the speed of light), the value of $\gamma$ approaches infinity. This means you would need an infinite amount of energy to actually reach the speed of light. This is why light itself is the only thing that can travel that fast—because photons have no rest mass to begin with!
The formula $KE = (\gamma - 1)m_0c^2$ is actually derived from Einstein's most famous equation. It shows that kinetic energy is simply the difference between the object's total energy when moving and its "rest energy" when sitting still. Even a tiny piece of lint has a massive amount of hidden energy locked inside its mass!