A block slides down the same rough incline at different angles while the coefficient…
PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A block slides down the same rough incline at different angles while the coefficient of kinetic friction remains constant. Which statement best describes how the magnitude of the block’s acceleration changes as the incline angle θ is increased from 20∘ to 40∘?
(a) It remains unchanged because both the downhill component of gravity and the kinetic friction force scale with sinθ, so their difference is constant.
(b) It increases because the component of the block’s weight parallel to the plane grows faster than the opposing friction decreases.
(c) It increases such that doubling the angle from 20∘ to 40∘ exactly doubles the acceleration, because the net force is assumed proportional to θ.
(d) It decreases because the component of weight parallel to the plane is taken to vary with cosθ, which becomes smaller as the slope gets steeper.