watch for this
343 ÷ 41.2 = 8.33 m. One wave of a low E is longer than the classroom is tall.
Sound travels 343 metres every second. A note that repeats 41 times a second therefore lays down one wave every 343 ÷ 41.2 = 8.33 metres. Higher notes repeat more often, so their waves are shorter — which is the whole of λ = v ÷ f, made out of a room.
The full lesson behind this: The bass →