> In normal playing, ...... the hammer is already > moving forward by virtue of the imparted momentum at the point of letoff, > and it simply travels off the jack tip of its own momentum, so that there is > no friction involved. There is considerable friction involved. Observation of the wear to the buckskin should make this obvious. The greater the force applied to the key, transmitted through the jack tip, the greater the friction at the knuckle (hammer butt, in the case of the upright), as the acceleration continually increases throughout the system. >if you have a football sitting on your open > palm, it will not leave your palm if you simply lift your hand gently. But > if you lift your hand quickly with sudden velocity, the ball will leave > contact with your palm and travel up by itself. Yes, but you will feel the friction as it leaves your fingertips with greater speed of motion than with a gentle slow motion. Frank Emerson
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