A cylindrical tank 2 m deep is open at the top. The tank, initially filled to its 4/9 of its depth, is subjected to rotation about its vertical axis. 1. Calculate the speed at which the vortex will be just 1 mm from touching the bottom of the tank. The inner diameter of the tank is 0.72 m. (10) 2. Will the water split from the tank if a rotational speed of 100 r/min is maintained? (10) 3. Describe the differences between a free vortex, a forced vortex and compound vortex. (5) [25]