1. The problem statement, all variables and given/known data A circular table of radius rotates about its center with an angular velocity 'w'. The surface of the table is smooth. A groove is dug along the surface of the table at a distance 'd' from the centre of the table till the circumference. A particle is kept at the starting point of groove and then released. Find the velocity of the particle when it reaches the end of the groove. 2. Relevant equations 3. The attempt at a solution Taking the table as the frame of reference, a pseudo force mw2x (x being the distance from the center of rotation) acts on the particle and solving the differential equation vdv/dx = mw2x will get us the answer. But my question is, how can we solve it seeing the motion as an observer on ground? With respect to ground there is no visible force (except the normal forces by the two surfaces of the groove it is exposed to; but they cancel each other out, don't they?) that acts on it but the ball still moves. My friend says it is coriolis force. If it is, can you please provide an intuitive explanation regarding coriolis force?