Question

Свинцовый шар, температура которого равна 20 градусов,со скоростью 300м/с ударился о стенку и остановился.Какая часть свинца при этом расплавилась?Считать,что вся энергия,выделившаяся при ударе, полностью поглощена свинцом. Помогите пожалуйста​

Answer 1

Ответ:

все должно быть правильно.

Answer 2

Calculation of the Melted Lead

To determine the amount of lead that melted when a lead ball with a temperature of 20 degrees Celsius and a velocity of 300 m/s hit a wall and came to a stop, we need to consider the energy absorbed by the lead.

The energy absorbed by the lead can be calculated using the principle of conservation of energy. The initial kinetic energy of the lead ball is converted into heat energy, which causes the lead to melt.

The formula to calculate the kinetic energy of an object is:

Kinetic Energy = 0.5 * mass * velocity^2

Since the lead ball comes to a stop, all of its kinetic energy is converted into heat energy. We can assume that the heat energy required to melt a certain amount of lead is known.

To find the mass of the lead that melted, we rearrange the formula:

Mass = (2 * Kinetic Energy) / (velocity^2)

Now, let's calculate the mass of the lead that melted.

Given: - Temperature of the lead ball = 20 degrees Celsius - Velocity of the lead ball = 300 m/s

First, we need to convert the temperature from Celsius to Kelvin:

Temperature in Kelvin = Temperature in Celsius + 273.15

So, the temperature of the lead ball in Kelvin is:

Temperature in Kelvin = 20 + 273.15 = 293.15 K

Next, we need to calculate the kinetic energy of the lead ball:

Kinetic Energy = 0.5 * mass * velocity^2

Since the velocity is given as 300 m/s, we can substitute the values into the equation:

Kinetic Energy = 0.5 * mass * (300^2)

Now, we can rearrange the equation to solve for mass:

Mass = (2 * Kinetic Energy) / (velocity^2)

Substituting the values into the equation:

Mass = (2 * (0.5 * mass * (300^2))) / (300^2)

Simplifying the equation:

Mass = 0.5 * mass

This equation implies that half of the mass of the lead ball melted upon impact with the wall. Therefore, half of the lead ball melted.

Please note that the calculation assumes that all the energy from the impact is absorbed by the lead and that the heat energy required to melt a certain amount of lead is known.