A1: 49 scale model of a ship is tested in a water tank. the speed of the proto-type is 10 m/s. the purpose of the tests is to measure the wave drag on the ship. find the velocity of the model and the ratio of the wave drag on the prototype to that on the model.

An electric motor is used to drive a power press which makes steel turning moment diagrams 323 pressings from a metal sheet. the motor runs at a mean speed of 50 rev/s. the torque required is 10.0nm for 0.2s, followed by 1.0nm for0.3 s with this sequence then being repeated. what is the minimum power required of the motor and the moment of incrtia required for the t1ywhcel if the speed fluctuations are to be restricted to 1.5%?