mecànica clàssica

F = a


m·d_{tt}^{2}[y(t)] = a
d_{tt}^{2}[y(t)] = (a/m)


d_{t}[y(t)] = (a/m)·t


y(t) = (a/2m)·t^{2}


E(t) = ∫ [ a ] d[y]
E(t) = ∫ [ a·d_{t}[y] ] d[t]
E(t) = ∫ [ a·(a/m)·t ] d[t]


E(t) = (a^{2}/2m)·t^{2}


(m/2)·d_{t}[y(t)]^{2} = (a^{2}/2m)·t^{2}