Re:Straightening out brass instruments (2013)
by kazinator on Friday March 15, 2019 @06:53PM
(#19405075)
The ball sticks to the magnet across the instrument wall. The forces are balanced: the magnet is pushing on the wall from one side and the ball from the other.
Now when the stop bar is struck by the mass, the magnet is violently moved away in a short amount of time. For a brief moment, the force is unbalanced, because the magnet has lost contact with the wall; only the ball is pushing on it.
The magnetic attraction may not in and of itself be strong, but the impulse is.
In physics, FΔt is called impulse. The impulse applied to an object changes its momentum: FΔt = Δmv.
If we keep the Δmv the same, but decrease Δt, we can raise the F.
Now when the stop bar is struck by the mass, the magnet is violently moved away in a short amount of time. For a brief moment, the force is unbalanced, because the magnet has lost contact with the wall; only the ball is pushing on it.
The magnetic attraction may not in and of itself be strong, but the impulse is.
In physics, FΔt is called impulse. The impulse applied to an object changes its momentum: FΔt = Δmv.
If we keep the Δmv the same, but decrease Δt, we can raise the F.