When a container of water is at rest (in an inertial reference frame) the surface of the water is flat (horizontal). However, when the container of water is placed on a rotating platform and spun at a constant angular velocity, the water height forms the shape of a parabola due to the centrifugal force in the rotating (non-inertial) reference frame. The observation of this effect was instrumental in encouraging Sir Isaac Newton to develop his laws of motion for inertial reference frames. This is a

91Y6Z