A cylinder filled with water of volume V is fitted with a piston and is placed horizontally. There is a small hole of cross-sectional area s at the other end of the cylinder, s being much smaller than the cross-sectional area of the piston (Fig. 9.5). Show that the work to be done by a constant force acting on the piston to squeeze all water from the cylinder in time t is given by W = 1/2 rV^3/s^2t^2 where r is the density of water. Neglect friction and viscosity.