A CLUBHEAD SPEED COEFFICIENT FOR THE GOLF SWING

The downswing of an expert golfer can be dissected into two distinct stages. In the first stage the left arm and clubshaft form a right angle which is firmly maintained while the combined system rotates with ever increasing angular velocity. In the latter stage the clubhead accelerates further and the angle between the arm and shaft decreases to zero. The ratio of clubhead speed at impact to clubhead speed at the final instant of the first stage is derived in closed form under the assumption that during the second stage the angular momentum and energy of the system remain constant. The phenomenon of 'snap ' in a golf swing is discussed in the resulting terms. 1