The formula is used to measure the speed of ocean waves, like tsunamis, that have very long wavelengths relative to the depth of the water. Tsunamis can have wavelengths greater than 700 kilometers (the average ocean depth is 3-4 kilometers). The formula estimates the tsunami's speed while it is in deeper waters (as it approaches shallower coastal waters, the tsunami slows down, its wavelength shortens, and its height increases).
Head lice and their eggs (nits) soon perish if separated from their human host. Adult head lice can live only a day or so off the human head without blood for feeding. Nymphs (young head lice) can live only for several hours without feeding on a human.
one of the biggest causes of re infestation is not getting the lice out of your environment lice will live up to 48 hours off your head and nits will survive for up to 10 days on your sofa your car seats your bedding etc you must treat your head and your home environment to end a lice infestation in one day and stop it from coming back