A quarter-scale turbine model is tested under a head of 15 m. The full-scale turbine is required to work under a head of 30 m and to run at a speed of 420 rpm. At what speed should the model be...

A quarter-scale turbine model is tested under a head of 15 m. The full-scale turbine is required to work under a head of 30 m and to run at a speed of 420 rpm. At what speed should the model be tested? If the model develops 1177.20 HP and uses 0.8
/s, what power will be developed from the prototype assuming that the overall efficiency of the prototype is 5% better than that of the model?