Serway & Jewett — Fluid Mechanics: Problem 46

Review. In a water pistol, a piston drives water through a large tube of area \(A_1\) into a smaller tube of area \(A_2\) as shown in Figure P14.46. The radius of the large tube is \(1.00\text{ cm}\) and that of the small tube is \(1.00\text{ mm}\). The smaller tube is \(3.00\text{ cm}\) above the larger tube. (a) If the pistol is fired horizontally at a height of \(1.50\text{ m}\), determine the time interval required for the water to travel from the nozzle to the ground. Neglect air resistance and assume atmospheric pressure is \(1.00\text{ atm}\). (b) If the desired range of the stream is \(8.00\text{ m}\), with what speed \(v_2\) must the stream leave the nozzle? (c) At what speed \(v_1\) must the plunger be moved to achieve the desired range? (d) What is the pressure at the nozzle? (e) Find the pressure needed in the larger tube. (f) Calculate the force that must be exerted on the trigger to achieve the desired range. (The force that must be exerted is due to pressure over and above atmospheric pressure.)