To push a certain box across a level floor at constant velocity requires that a horizontal force be applied to the box. The magnitude of this force is half as great as the vertical force required to lift the box. Find the coefficient of kinetic friction between box and floor.

Coefficient of kinetic friction = 0.5

Explanation:

Force required to push the box = 0.5 * weight of box = 0.5 * W

Equation for friction:

Frictional force = coefficient of friction * normal force

Here, normal force = weight of the box = W

Frictional force and force required to push the box are equal. This is because the box is moving at constant velocity, with net forces = 0.

Thus, frictional force = 0.5 * W

Thus we can write the frictional equation state before with substituted values:

0.5 * W = (coefficient of friction) * W

Coefficient of friction = 0.5