(Solved): The figure shows a flat grinding machine. The workpiece oscillates below a 90 mm diameter grinding ...

The figure shows a flat grinding machine. The workpiece oscillates below a 90 mm diameter grinding wheel rotating by a connecting rod mechanism crank, which has a 22mm crank, a 157mm connecting rod and 40mm offset. The crank rotates at 30 rpm, while the grinding wheel rotates at 3450 rpm. Calculate the relative acceleration of the grinding wheel's contact point with the workpiece when ? = 205°.