WAEC Physics 2021 Paper

Concept:When a body moves in a circle with constant speed, its velocity changes direction continuously, so it is accelerating. This acceleration is always directed toward the centre of the circle.Explanation:The ball moves in a horizontal circle with constant speed, so its motion is uniform circular motion.The direction of velocity keeps changing, hence there is an acceleration even though speed is constant.This acceleration is called centripetal acceleration, and it is given by $a = \dfrac{v^2}{r}$, directed toward the centre $O$.Therefore, the acceleration of the ball points toward the centre of the circle.Answer:C. Toward centre $O$