User:Tetrahedron93/DevsSums

AK-47
$$Energy_\text{bullet} = 0.5 * 0.010kg * (641.3m/s)^2 = 2056.32845J$$
 * Muzzle velocity = 641.3m/s
 * Weight of bullet = 10.0g

$$E_k = 0.5mv^2$$ $$v^2 = \frac{E_k}{0.5m}$$ $$v = \sqrt{\frac{E_k}{0.5m}}$$

$$velocity_\text{armor} = \sqrt{\frac{E_k}{0.5m}} = \sqrt{\frac{2056.32845}{0.5x12}} =~ 18.5127364m/s$$