Question

В двух неподвижных лодках находятся мальчики. Масса первой лодки с мальчиком составляет 120кг,второй -80кг.После того как мальчик на второй лодке оттолкнул от себя первую лодку,его лодка приобрела скорость,равпую 1,5м/с. Какую скорость приобрела первая лодка.

Answer 1

1 м/с
если нужно решение, скажи

Answer 2

Problem Analysis

We have two stationary boats with boys on them. The mass of the first boat with the boy is 120 kg, and the mass of the second boat is 80 kg. After the boy on the second boat pushes away the first boat, the second boat acquires a velocity of 1.5 m/s. We need to find the velocity acquired by the first boat.

Solution

To solve this problem, we can use the principle of conservation of momentum. According to this principle, the total momentum before the interaction is equal to the total momentum after the interaction.

The momentum of an object is given by the product of its mass and velocity: momentum = mass × velocity.

Let's denote the mass of the first boat as m1, the mass of the second boat as m2, the velocity of the first boat as v1, and the velocity of the second boat as v2.

Before the interaction, the total momentum is the sum of the individual momenta of the two boats: m1 × v1 + m2 × v2 = 0 (since the boats are stationary)

After the interaction, the second boat acquires a velocity of 1.5 m/s. Let's denote the final velocity of the second boat as v2f.

The total momentum after the interaction is the sum of the individual momenta of the two boats: m1 × v1f + m2 × v2f = 0

Since the first boat is stationary after the interaction, its final velocity (v1f) is 0.

Substituting the values into the equation, we get: 120 kg × 0 + 80 kg × 1.5 m/s = 0

Simplifying the equation, we find: 120 kg × 0 + 120 kg × v1f = 80 kg × 1.5 m/s

Solving for v1f, we get: v1f = (80 kg × 1.5 m/s) / 120 kg

Calculating the value, we find: v1f = 1 m/s

Therefore, the first boat acquires a velocity of 1 m/s after the interaction.

Answer

The first boat acquires a velocity of 1 m/s after the boy on the second boat pushes away the first boat.