JAMB Physics 2013 Paper

Concept:When two perpendicular forces act on a body, their resultant forms the hypotenuse of a right-angled triangle.The force that makes an angle with the resultant can be found using the cosine of that angle.Explanation:Let the two perpendicular forces be $P$ and $Q$.Their resultant is $R = 50\,\mathrm{N}$.The force $P$ makes an angle of $30^\circ$ with the resultant $R$.In the right triangle, $R$ is the hypotenuse, and $P$ is adjacent to the $30^\circ$ angle.So, $P = R\cos 30^\circ$.Substitute the given values: $P = 50\cos 30^\circ$.Since $\cos 30^\circ = 0.866$, we get $P = 50 \times 0.866$.Thus, $P = 43.3\,\mathrm{N}$.This matches option C.Answer:$43.3\,\mathrm{N}$