Which term denotes the energy input that starts wave formation?

Which term denotes the energy input that starts wave formation?

• A. Fetch
• B. Group Velocity
• C. Disturbing Force
• D. Interference

Answer: (C)

Energy input that starts wave formation is described by the disturbing force. In the ocean, wind is the typical disturbing force: it transfers energy to the water surface, creating initial surface irregularities that gravity (and, for very small waves, surface tension) then act on to form visible waves. Fetch, the distance over which the wind blows, affects how much energy can be transferred and thus the eventual size of waves, but it is not the initiating energy input itself. Group velocity is about how fast the wave energy travels, and interference is the interaction of waves, not how they start. So the term that denotes the energy input that starts wave formation is the disturbing force.

Energy input that starts wave formation is described by the disturbing force. In the ocean, wind is the typical disturbing force: it transfers energy to the water surface, creating initial surface irregularities that gravity (and, for very small waves, surface tension) then act on to form visible waves. Fetch, the distance over which the wind blows, affects how much energy can be transferred and thus the eventual size of waves, but it is not the initiating energy input itself. Group velocity is about how fast the wave energy travels, and interference is the interaction of waves, not how they start. So the term that denotes the energy input that starts wave formation is the disturbing force.