A hydraulic pump with performance characteristics represented in Fig. 10.28 delivers a flow rate of 48.5 gpm at zero pressure and 46.5 gpm at 1500 psig at a rotating speed of 2000 rpm. The displacement volume is 5 9 in3 revolution. It requires Q=20 gpm at p=1500 psig at one operating condition. Determine the volumetric efficiency at zero pressure. Compute the required pump power input, the power delivered to the load, and the power dissipated by throttling at this condition. Compare with the power dissipated by using (i) a variable-displacement pump at 3000 psig and (ii) a pump with load sensing that operates at 100 psi above the load requirement.