A plastic ball with a mass of 20 g flies at a speed of 60 cm / s, collides with the same resting ball and sticks to it.

A plastic ball with a mass of 20 g flies at a speed of 60 cm / s, collides with the same resting ball and sticks to it. What is the speed of the balls after the collision?

To calculate the required speed of identical plasticine balls after an inelastic collision, we apply the law of conservation of momentum: (m1 + m2) * V = m1 * V1, whence V = m1 * V1 / (m1 + m2) = m * V1 / (m + m) = V1 / 2.

Variables: V1 – speed of the first plasticine ball (V1 = 60 cm / s; in SI V1 = 0.6 m / s).

Let’s calculate: V = V1 / 2 = 0.6 / 2 = 0.3 m / s.

Answer: After the collision, the plasticine balls will move at a speed of 0.3 m / s.