1. The problem statement, all variables and given/known data A plane with a fully laden mass of 500 tonnes is flying due north at a steady speed of 1000kmh^-1 and is located at a latitude of 51 degrees north at a specific time. What force in an east-west direction is required to keep the plane on course along a fixed line of longitude. 2. Relevant equations 3. The attempt at a solution So due to the inertial effect of the Coriolis force, the plane requires a force acting east to keep it on a fixed line of longitude because the coriolis force is acting west on the plane. The magnitude of the coriolis force is given by this equation: mx'' = -2mw(z'cos(theta) - y'sin(theta)) where x is the east direction , z is vertically up, y is north, theta is the latitude So in this case, because there is no velocity in the z direction, it becomes: mx'' = -2mw(-y'sin(theta)) Is this right?