Respostas

2014-04-04T13:42:27-03:00
Resposta

m = 20000g = 20kg
V = 18km/h = 5m/s

Formula

Ec =  \frac{m.V ^{2} }{2}

Ec = \frac{20.5 ^{2} }{2}

Ec = \frac{500}{2}

Ec = 250J