Halliday, Resnick & Walker — Fluids: Problem 30

30 In Fig. 14-33, a spring of spring constant \(3.75 \times 10^4 \text{ N/m}\) is between a rigid beam and the output piston of a hydraulic lever. An empty container with negligible mass sits on the input piston. The input piston has area \(A_i\), and the output piston has area \(18.0 A_i\). Initially the spring is at its rest length. How many kilograms of sand must be (slowly) poured into the container to compress the spring by \(5.00 \text{ cm}\)?