Q. A box weighing 599 N is pushed along a horizontal floor at constant velocity with a force of 291 N parallel to the floor. What is the coefficient of kinetic friction between the box and the floor?
Q. An airplane with a mass of 2.6 106 kg. has the air flow past the lower surface of the wings at 100 m/s. If the wings have a surface area of 1200 m2, how fast must the air flow over the upper surface of the wing if the plane is to stay in the air?