WAEC Physics 2019 Paper

Concept:Einstein’s mass-energy equivalence states that $E = mc^2$, where $c$ is the speed of light.Explanation:Since $c^2$ is constant, $E$ is directly proportional to $m$, i.e. $E \propto m$. A direct proportional relationship is always shown by a straight line that passes through the origin. Therefore, as mass increases, energy increases linearly from zero on the correct graph.Answer:Option A