a 40 kg block is being pulled at constant velocity across a horizontal surface by a 150 N force at an angle 60 above the horizontal. What is the coefficient of kinetic friction between the block and the floor

0.19

Explanation:

mass of block, m = 40 kg

F = 150 N

Angle make with the horizontal, θ = 60 degree

Let μ be the coefficient of kinetic friction

The component of force along horizontal direction is F Cos θ

= 150 cos 60 = 75 N

As it is moving with constant velocity it mean the acceleration of the block is zero.

Applied force in horizontal direction = friction force

75 = μ x Normal reaction

75 = μ x m x g

75 = μ x 40 x 9.8

μ = 0.19

Thus, the coefficient of kinetic friction is 0.19.