A bullet weighing 10 g, flying horizontally at a speed of 400 m / s, hits an obstacle and stops

A bullet weighing 10 g, flying horizontally at a speed of 400 m / s, hits an obstacle and stops. What is the change in momentum of a bullet?

m = 10 g = 0.01 kg.

V0 = 400 m / s.

V = 0 m / s.

Δp -?

The momentum of a bullet p is called a physical quantity, which is determined by the formula: p = m * V.

Δp = p – p0 = m * V – m * V0 = m * (V – V0).

Δp = 0.01 kg * (0 m / s – 400 m / s) = – 4 kg * m / s.

A “-” sign indicates that the momentum of the bullet has decreased.

Answer: the momentum of the bullet decreased by Δp = 4 kg * m / s.