The turbine rotor of a ship has a mass of 6 tonnes and radius of gyration of 0.5 m. It rotates at 1500 r.p.m. clockwise, when looking from the stern. If the ship travels at a speed of 25 m/s and steer to the left in a curve of radius 75 m, the gyroscopic couple will be
1
25000 π
2
12500 π
3
6250 π
4
3125 π