Friction (in Earth's atmosphere). Outside of Earth's atmosphere, there is no mechanical heating that is measurable.
Weightlessness
Immunity occurs when the system recognizes a foreign substance and responds by producing : antibodies.
Chemical weathering occurs more rapidly in warm, wet climates, and mechanical weathering occurs more in cold climates.
Mechanical
By definition mechanical digestion is a physical part of digestion.
teeth
Spermatogenesis.
In the stomach and the mouth
Mechanical digestion.
... friction occurs.
Mechanical
electrical to heat and mechanical