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Q19. A single acting vertical bilge pump operates at 40 rev/min against a constant discharge pressure of 2.8 bar. The pump delivers 10 m³/hour of fresh water for the single 120 mm diameter piston. The combined mass of the piston and entrapped water is 18 kg and the piston can be assumed to move with simple harmonic motion. The piston is moving upwards and is 80 mm away from the top of the stroke. Calculate EACH of the following:

(a) The force required to move the piston;

(b) The input power to the pump motor at the given instant if the motor efficiency is 80%.