WAEC Physics 2023 Paper

Concept:For uniform acceleration, distance is found using the equation of motion $S = ut + \frac{1}{2}at^2$.Explanation:The body starts with initial velocity $u = 20\ \mathrm{m\,s^{-1}}$.It moves for time $t = 15\ \mathrm{s}$ with constant acceleration $a$.Using the second equation of motion:$$S = ut + \frac{1}{2}at^2$$Substitute the given values:$$S = 20(15) + \frac{1}{2}a(15)^2$$Simplify each term:$$20(15) = 300$$$$(15)^2 = 225$$Therefore:$$S = 300 + \frac{1}{2}a(225) = 300 + \frac{225a}{2}$$This expression matches option B exactly.Answer:The correct equation for distance traveled is:$$S = 300 + \frac{225a}{2}$$Hence, the correct option is B.