A block of mass is placed on a rough plane that makes an angle with the horizontal
MATHEMATICS · Multi-part · A Level · Mathematics · Forces and Newton's laws · Forces and Newton's laws
Problem
A block of mass m is placed on a rough plane that makes an angle θ with the horizontal. The block is released from rest and begins to slide down the plane.
(i) Draw a clearly labelled free-body diagram for the block.
(ii) Identify the forces responsible for motion parallel and perpendicular to the plane and describe how the weight of the block is resolved into these components.
(iii) Explain, without performing numerical calculation, why the acceleration of the block is independent of its mass even though the weight itself depends on mass.
(iv) State the condition on θ and the coefficient of kinetic friction μk under which the block would move with constant speed instead of accelerating.