Why do you feel heavier in an elevator?

Think the normal force always equals mg? It doesn't. See when Fₙ = m(g + a) takes over — elevators, inclines and more, in a short visual explainer.

Most students learn Fₙ = mg as a rule — but it's only a special case. The normal force is whatever Newton's second law demands of the surface. Step into an elevator accelerating upward and Fₙ rises above mg (you feel heavier); when it accelerates downward, Fₙ drops below mg (you feel lighter). On an incline, it falls below mg too. The general equation Fₙ = m(g + a) handles every case — the elevator, the incline, and the flat table where a = 0. This 60-second visual walks through when the shortcut breaks and the one equation that always works.