Two stationary boats are boys, the mass of the first boat with the boy is 120 kg

Two stationary boats are boys, the mass of the first boat with the boy is 120 kg, the second 80 kg after the boy on the second boat pushed the first boat away from him his boat Got a speed equal to one point five meters per second what speed the first boat acquired.

Let’s write down the law of conservation of momentum for the first and second boats (before repulsion, the sum of the momentum is equal to zero).
m₁V₁ + m₂V₂ = 0, where m₁ and V₁ are the mass and speed of the first boat, m₂ and V₂ are the mass and speed of the second boat.
Substitution of values:
120 kg * V₁ + 80 kg * 1.5 m / s = 0;
V₁ = – (80 kg * 1.5 m / s) / 120 kg = -1 m / s.

Answer: The first boat acquired a speed of -1 m / s (the minus sign indicates that the V₁ direction is opposite to the V₂ direction).