For the following questions answer them individually
For a flow to be rotational, velocity normal to the plane of area should be equal to the _____.
A fluid in which resistance to deformation is independent of the shear stress, is called _____.
A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used?