A 2 kg block is pressed against a vertical wall of coefficient of friction μ = 0.2 by a 40 N force as shown. Find the friction force acting on the block.

Question

G1 Physics · Accepted Answer

The force makes 60° with the vertical, so its upward component is 40 cos60° = 20 N. The block weight is also 2×10 = 20 N downward. Vertical forces already balance, so no friction is required. Therefore friction is zero.