In physics, the Coriolis force is an inertial force (cried a fictitious force an aw) actin on objects which are in motion relative tae a rotatin reference frame.

In the inertial frame o reference (upper pairt o the picture), the black baw muives in a straicht line. Houever, the observer (reid dot) who is staundin in the rotating/non-inertial frame o reference (lawer pairt o the pictur) sees the object as follaein a curved path due tae the Coriolis an centrifugal forces present in this frame.