Answer:
The maximum value of θ that will cause the block to remain stationary on the inclined surface is 21.8°
Explanation:
Given;
coefficient of static friction, μ = 0.4
for the block to remain stationary on the inclined plane, force pushing the block upward must be equal to the force acting downwards.
μR = mgsinθ
μmgcosθ = mgsinθ
μcosθ = sinθ
μ = sinθ/cosθ
μ = tanθ
θ = tan⁻¹(0.4) = 21.8°
Therefore, the maximum value of θ that will cause the block to remain stationary on the inclined surface is 21.8°
