Question

Calcule a velocidade de um carro de massa 1 tonelada cuja energia cinética tenha valor 250 kJ.

Answer 1

$m = 1t = 1000kg\\E_c = 250kJ = 250000J\\\\E_c = \frac{mv^2}{2}\\250000 = \frac{1000v^2}{2}\\1000v^2 = 250000 \cdot 2\\1000v^2 = 500000\\v^2 = \frac{500000}{1000}\\v^2 = 500\\v = \sqrt{500}\\\boxed{v \approx 22,36m/s}$