WAEC Physics 2018 Paper

Concept:The velocity ratio of an inclined plane is the ratio of the length of the slope to the vertical height, which depends on the angle $\theta$.Explanation:For an inclined plane, the velocity ratio is given by $VR = \frac{l}{h}$.Here, $l$ is the length of the incline and $h$ is the vertical height.From the geometry of the plane, $h = l \sin\theta$.So, $VR = \frac{l}{l \sin\theta} = \frac{1}{\sin\theta}$.As $\theta$ increases, $\sin\theta$ also increases.Therefore, the value of $\frac{1}{\sin\theta}$ decreases.Hence, the velocity ratio of the plane decreases as $\theta$ increases.Answer:B. decreases