A pencil of length L, with the pencil point at one end and an eraser at the

Question:

A pencil of length L, with the pencil point at one end and an eraser at the other end, is initially standing vertically on a table with the pencil point on the table. The pencil is let go and falls over. Derive a formula for the speed with which the eraser strikes the table, assuming that the pencil point does not move.