WAEC Physics 2019 Paper

Concept:Newton's second law states that the acceleration of a body depends on the net force acting on it and its mass.The relation is $a = \frac{F}{m}$.Explanation:Let the original force be $F$ and the original mass be $m$.Then the original acceleration is $a = \frac{F}{m}$.The force is halved, so the new force is $F' = \frac{F}{2}$.The mass is doubled, so the new mass is $m' = 2m$.The new acceleration is:$$a' = \frac{F'}{m'} = \frac{\frac{F}{2}}{2m} = \frac{F}{4m} = \frac{1}{4}\left(\frac{F}{m}\right) = \frac{a}{4}.$$Thus, the new acceleration is one-quarter of the original acceleration.Answer:The resulting acceleration is quartered.Correct option: B.