A window washer pushes his scrub brush up a vertical window at constant speed by applying a

Question:

A window washer pushes his scrub brush up a vertical window at constant speed by applying
a force F as shown in Fig. 5.65. The brush weighs 12.0 N and the coefficient of kinetic friction is μk = 0.150. Calculate (a) the magnitude of the force F and (b) the normal force exerted by the window on the brush.

53.1%