Unless the rigid objects were truly infinitely strong, they would break.
Consider the rigid object moving smoothly along the regular curve.
A long, rigid object protruded from the mouth and extended to the ground.
Small rigid objects (such as rocks) are sometimes mixed in a rotating drum or tumbler.
As it turns out, uniformly distributed measures are very rigid objects.
The boundary conditions for the Oseen flow around a rigid object are:
The water is not even a rigid object, so the part nearby simply responds to local attraction.
In mathematics, a particle is a point-like, perfectly rigid, solid object.
An arbitrary rigid rotor is a 3-dimensional rigid object, such as a top.
The secret seems to lie in the fact that the sub- marine is a rigid object and the whale is not.