A projectile is launched along the axis at a fixed latitude on the surface of the Earth. The projectile experiences the effect of the Coriolis force, which is a fictitious force observed in a rotating reference frame (blue curve), deflecting the trajectory clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere, with respect to an inertial frame (red curve). This effect is important for oceanic currents, prevailing winds, hurricanes, and so on.

Newton's second law in a rotating coordinate system is

,

where the terms on the right-hand side are the transverse force (proportional to the angular velocity), the Coriolis force, and the centripetal force. The equations for the components are

It can be shown that a solution (taking and ) is

Neglecting terms in , the solutions are

See R. L. Zimmerman and F. I. Olness, Mathematica For Physics, 2nd ed., Reading, MA: Addison–Wesley, 2002.