(a) Calculate the retarding force due to the viscosity of the air layer between a cart and a level air track given the following information-air temperature is 20° C, the cart is moving at 0.400 m/s, its surface area is 2.50 x 10^-2 m, and the thickness of the air layer is 6.00 x 10^-5 m.

(b) What is the ratio of this force to the weight of the 0.300-kg cart?