A hydroelectric power plant uses spinning turbines to transform the kinetic energy of moving water into electric energy with 74 % efficiency. That is, 74 %of the kinetic energy becomes electric energy. A small hydroelectric plant as the base of a dam generates 50 MW of electric power when the falling water has a speed of 18 m/s.

What is the water flow rate − kilograms of water per second − through the turbines?