JEE Main Physics question
A 20 kg block is initially at rest on a rough horizontal surface. A horizontal force of 75 N is required to set the block in motion. After it is in motion, a horizontal force of 60 N is required to keep the block moving with constant speed. The coefficient of static friction is
Answer: (A)
Solution
μₛ = /(mg) = 75/(20×9.8) = 75/196 ≈ 0.38.