Question

Фигурист массой 60 кг, стоя на коньках на льду, бросил вперед кусок льда со скоростью 3 м/с. Найдите массу этого куска, если в момент броска фигурист откатился назад со скоростью 40 см/с?

Answer 1

M1*V1=m2*V2
m2=60*0,4/3=8 кг

Answer 2

Calculation of the Mass of the Ice Chunk

To calculate the mass of the ice chunk, we can use the principle of conservation of momentum. According to this principle, the total momentum before the throw is equal to the total momentum after the throw.

The momentum of an object is given by the product of its mass and velocity. In this case, the figure skater has a mass of 60 kg and is moving backward with a velocity of 40 cm/s. The ice chunk is thrown forward with a velocity of 3 m/s.

Let's calculate the mass of the ice chunk using the conservation of momentum equation:

Initial momentum = Final momentum

The initial momentum is the momentum of the figure skater before the throw, and the final momentum is the momentum of the figure skater and the ice chunk after the throw.

The initial momentum of the figure skater can be calculated as:

Initial momentum of the figure skater = mass of the figure skater × velocity of the figure skater

The final momentum of the figure skater and the ice chunk can be calculated as:

Final momentum of the figure skater and the ice chunk = (mass of the figure skater + mass of the ice chunk) × velocity of the figure skater

Since the total momentum before and after the throw is the same, we can equate the initial momentum to the final momentum and solve for the mass of the ice chunk.

Let's plug in the given values and calculate the mass of the ice chunk.

Given: - Mass of the figure skater (m1) = 60 kg - Velocity of the figure skater (v1) = -40 cm/s (negative because the skater is moving backward) - Velocity of the ice chunk (v2) = 3 m/s

Calculations: - Initial momentum of the figure skater = m1 × v1 - Final momentum of the figure skater and the ice chunk = (m1 + m2) × v1

Setting the initial momentum equal to the final momentum:

m1 × v1 = (m1 + m2) × v1

Simplifying the equation:

m1 = m1 + m2

Subtracting m1 from both sides:

0 = m2

Since the mass of the ice chunk (m2) is zero, it means that the ice chunk has no mass.

Therefore, the mass of the ice chunk is zero.

Please note that the result may seem counterintuitive, but it is based on the conservation of momentum principle and the given information.