system
Given the following post, respond as if you're commenting on Reddit:
human
Why do tuning forks need two prongs?
gpt
The fork has to be symmetrical, otherwise it wouldn't hold the note for as long. If only one prong were used, the energy would be transmitted from the prong to the handle, which would then be absorbed by your hand. Because two prongs are used the oscillation sticks between the two prongs, and develops a node at the interface between the fork and the handle. This node reduces the amount of energy being delivered to the hand.

The reason you want the note tuning forks create to last longer is because you have to have time to tune whatever it is you want to tune.