Question

Тело массой 10 кг упало с высоты 20 м. На сколько увеличится внутренняя энергия в момент удара о землю, если на его нагревание идет 30% кинетической энергии тела? Желательно с исходными формулами

Answer 1

Ответ:

DU=0,3*mg*h=0,3*10*20=60 Дж.

Объяснение:

Answer 2

Calculation of Change in Internal Energy

To calculate the change in internal energy when a body of mass 10 kg falls from a height of 20 m, we can use the following formula:

Change in internal energy = 30% of kinetic energy

First, let's calculate the initial kinetic energy of the body using the formula:

Kinetic energy = 0.5 * mass * velocity^2

The velocity just before impact can be calculated using the formula:

Velocity = sqrt(2 * g * height)

Where: - g = acceleration due to gravity (approximately 9.81 m/s^2) - height = 20 m

Now, we can calculate the kinetic energy and then find 30% of it to determine the change in internal energy at the moment of impact.

Calculation Steps

1. Calculate the velocity just before impact: - Velocity = sqrt(2 * 9.81 m/s^2 * 20 m)

2. Calculate the kinetic energy: - Kinetic energy = 0.5 * 10 kg * (velocity)^2

3. Determine 30% of the kinetic energy: - Change in internal energy = 30% * Kinetic energy

Calculation

Let's perform the calculations:

1. Calculate the velocity: - Velocity = sqrt(2 * 9.81 m/s^2 * 20 m) - Velocity ≈ 19.8 m/s

2. Calculate the kinetic energy: - Kinetic energy = 0.5 * 10 kg * (19.8 m/s)^2 - Kinetic energy ≈ 1962 J

3. Determine 30% of the kinetic energy: - Change in internal energy = 30% * 1962 J - Change in internal energy ≈ 588.6 J

Conclusion

The change in internal energy at the moment of impact when 30% of the body's kinetic energy is used for heating is approximately 588.6 joules.