A plasticine ball weighing 20g collides with a steel ball weighing 40g and sticks to it.

| February 18, 2021 | education

A plasticine ball weighing 20g collides with a steel ball weighing 40g and sticks to it. The speed of their joint movement became 2m / s. The steel ball was at rest before the collision, and the plastic one had a speed …?

Impulse conservation law. The sum of impulses making up a closed system does not change over time for any interactions of bodies.

Therefore, the sum of the impulses before the interaction of the balls is equal to the sum of the impulses after the interaction.

m1V1 + m2V2 = m1V + m2V.

m1 is the mass of the plasticine ball, kg.

m2 is the mass of the steel ball, kg.

V1 – speed of the plasticine ball, m / s.

V2 is the speed of the steel ball, equal to zero.

V is the joint speed of the balls.

m1V1 = (m1 + m2) × V.

V1 = (m1 + m2) × V / m1 = (0.02 + 0.04) × 2 / 0.02 = 6 m / s.

Answer: the speed of the ball is 6 m / s.



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