Since the vector of the coriolis term always points perpendicular to the velocity with respect to the rotating coordinate system, it follows that in the case of a restoring force that is a harmonic force, the eccentricity in the trajectory will show up as a small circular motion with respect to the rotating coordinate system.
32.
The objective is to use the Mohr circle to find the stress components \ sigma _ \ mathrm { n } and \ tau _ \ mathrm { n } on a rotated coordinate system ( x', y'), i . e ., on a differently oriented plane passing through P and perpendicular to the x-y plane ( Figure 4 ).
33.
This more general context makes clear the correspondence between the concepts of centrifugal force in rotating coordinate systems and in stationary curvilinear coordinate systems . ( Both of these concepts appear frequently in the literature . ) For a simple example, consider a particle of mass " m " moving in a circle of radius " r " with angular speed " w " relative to a system of polar coordinates rotating with angular speed " W ".
