[tongzilla]

In 1-L-11 Homer states that clubhead force and motion is on plane at right angles to the longitudal Center of Gravity and varies with the Speed, Mass and Swing Radius.

I don't understand this sentence because im unsure what the longitudinal center of gravity is.....

Longitudinal center of gravity as opposed to the transversional centre of gravity.

To find the Longitundinal centre of gravity, hang a string with a weight on the end from the grip. The string should hang vertically and go through the club's sweetspot.

To find the transversional center of gravity, just try to balance the length of the club on your index finger. Obvisouly, the fulcrum (your finger) should be nearer the clubhead because of its weight.