Question
A block is at rest on a rough horizontal plane. The coefficient of friction between the block and the plane is 1.25.
(i) State, giving a reason for your answer, whether the minimum vertical force required to move the block is greater or less than the minimum horizontal force required to move the block. [2]
A horizontal force of continuously increasing magnitude P N and fixed direction is applied to the block.
(ii) Given that the weight of the block is 60 N, find the value of P when the acceleration of the block is 4 m s−2.
Answer/Explanation
Ans:
(i) Less than
F = 1.25W so W< F
(ii) [P – 60 × 1.25 = 6 × 4]
P = 99