Toenail?
Correct me if I'm wrong.
If we didn't have sun's energy there wouldn't be life on earth.Sunlight is what plants eat. Animals and bugs eat the plants that have sunlight in them. Humans and other animals then eat the bugs and the animals that ate the plants. Indirectly every living thing has sunlight feeding it.
Hope this helps!
The answer is wavelength. It is the distance between corresponding points of two consecutive waves (corresponding points are particles or points in the same phase, meaning the points have completed identical fractions of their periodic motion. In a transverse wave it is the distance between two successful crests or troughs while in a longitudinal wave is the distance between two successful compressions or rarefactions.