The cylinder is subjected to a load that has a weight W. If the coefficients of rolling

Question:

The cylinder is subjected to a load that has a weight W. If the coefficients of rolling resistance for the cylinder's top and bottom surfaces are aA and aB respectively, show that a force having a magnitude of P = [W(aA + aB)]/2r is required to move the load and thereby roll the cylinder forward. Neglect the weight of the cylinder.

W P B