Calling on your experience and physical intuition, answer the following: (a) Will the workpiece cool more quickly in the vertical or horizontal arrangement if the only air motion that occurs is due to buoyancy of the air near the hot surfaces of the workpiece (referred to as free or natural convection)? (b) If a fan blows air over the workpiece (referred to as forced convection), would you expect the cooling rate to increase or decrease? Why? 1.26 An automobile engine normally has a coolant circulating through passageways in the engine block and then through a finned-tube radiator. Lawn mower engines normally have finned surfaces directly attached to the engine block, with no radiator, in order to achieve the required cooling. Why might the cooling strategies be different in these two applications?