>>3773542I think they are indeed measuring the height (or should I say depth) of the hole h, I don't know japanese, but from the diagram I'm guessing they will drop something down the hole that's the arrow pointing down on the right and then when it hits the bottom it will make a sound and that's the arrow on the left. Since they presumably know gravity g and the speed of sound v, that leaves only T to be measured which they will probably do, egg even has headphones so she'll probably be listening for the sound. Or maybe not, I was never good with physics.
