What is the velocity of a 12 g bullet if 2.4 g of gunpowder burns out when fired?

What is the velocity of a 12 g bullet if 2.4 g of gunpowder burns out when fired? Specific heat of combustion of gunpowder 38 * 10 ^ 5 J / kg.

Data: m1 (bullet weight) = 12 g; m2 (mass of powder burnt when fired) = 2.4 g.

Reference data: according to the condition q (specific heat of combustion of gunpowder) = 38 * 105 J / kg.

SI: m1 = 12 g = 12 * 10 ^ -3 kg; m2 = 2.4 g = 2.4 * 10 ^ -3 kg.

If all the energy from the combustion of gunpowder goes to increase the speed of the bullet, then the equality is true: Q = Ek and q * m ^ 2 = m1 * V ^ 2/2, whence V = √ (2 * q * m ^ 2 / m1).

Let’s perform the calculation: V = √ (2 * 38 * 10 ^ 5 * 2.4 * 10 ^ -3 / (12 * 10 ^ -3)) ≈ 1233 m / s.

Answer: The bullet speed will be equal to 1233 m / s.