Physics

The key is recognizing that kinetic energy depends on both mass and speed through the formula $KE = \frac{1}{2}mv^2$. You have two of the three quantities (energy and speed), so you can rearrange to solve for the unknown mass. This is a straightforward algebra problem once you set up the relationship correctly.

The key is recognizing that kinetic energy depends on both mass and speed through the formula $KE = \frac{1}{2}mv^2$. You have two of the three quantities (energy and speed), so you can rearrange to solve for the unknown mass. This is a straightforward algebra problem once you set up the relationship correctly.