Period of a wave is the:

## The Reasoning Think of watching waves at Bar Beach, Lagos. **Period (T)** is literally how much *time* it takes for one complete wave to pass you – from crest to crest, or from any point back to that same point again. It's measured in **seconds**. The formula connects everything: **v = fλ** (wave speed = frequency × wavelength), and since frequency f = 1/T, the period is central to wave motion. If a wave completes 5 cycles in 5 seconds, T = 1 second per cycle. ## Why the Wrong Options Tempt You **A) Distance between crests** – This is *wavelength* (λ), not period. Distance vs. time – don't mix them! **C) Max displacement** – This is *amplitude* (A), how high the wave rises. Completely different property. **D) Speed** – That's wave velocity (v), how fast the wave travels forward. These all describe waves, but period specifically answers "How long?" not "How far?" or "How much?" ## Quick Takeaway **Period = Time per cycle** – whenever you see "period," think stopwatch ⏱️, not ruler 📏.