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## Main Question or Discussion Point

Hi there,

I am trying to understand the physics acting on a discus thrower, namely at their feet when they throw a discuss.

first the player spins to pick up momentum for the discus, he or she does this by pushing on the ground but when the actual discus leaves the hand, is there an action reaction? isn't the discus just leaving their hand? if you were to simplify the problem to just a spinning arm on a pivot with a mass at the end, when the mass leaves the arm, does it push back on the arm, does the pivot feel the tangential force back?

In other words if the discus arm was in space or on water, assuming you could spin it up, when you release it, would the arm be flung back? would the displacement of the pivot change? not in a circle but linearly?

I am trying to understand the physics acting on a discus thrower, namely at their feet when they throw a discuss.

first the player spins to pick up momentum for the discus, he or she does this by pushing on the ground but when the actual discus leaves the hand, is there an action reaction? isn't the discus just leaving their hand? if you were to simplify the problem to just a spinning arm on a pivot with a mass at the end, when the mass leaves the arm, does it push back on the arm, does the pivot feel the tangential force back?

In other words if the discus arm was in space or on water, assuming you could spin it up, when you release it, would the arm be flung back? would the displacement of the pivot change? not in a circle but linearly?