Q.10 Explain why objects moving in fluids must have special shapes.

When a body moves through a fluid, it experiences an opposing force which opposes the relative motion of the body through the fluid.

The opposing force is known as the drag force which is a result of friction between the surface of the body and the fluid.

This frictional force depends on the shape of the body. Objects with a special shape can minimize the effect of frictional force, thus making it more easier for movement of the body through the fluid.