Question

Тело массой 100 г подброшено вертикально вверх со скоростью 40 м/с. Определите кинетическую энергию тела в начальный момент и потенциальную энергию на максимальной высоте подъема. Сравните эти величины. Определите сумму потенциальной и кинетической энергий через 3 с от начала движения. Сравните эту сумму с кинетической энергией в начале движения. Сделай вывод.

Answer 1

Calculation of Kinetic Energy at the Initial Moment

The kinetic energy of an object can be calculated using the formula:

Kinetic Energy = (1/2) * mass * velocity^2

Given that the mass of the object is 100 g (0.1 kg) and the velocity is 40 m/s, we can calculate the kinetic energy at the initial moment:

Kinetic Energy = (1/2) * 0.1 kg * (40 m/s)^2

Let's calculate the value:

Kinetic Energy = 0.5 * 0.1 kg * (40 m/s)^2 = 80 J.

Therefore, the kinetic energy of the body at the initial moment is 80 Joules.

Calculation of Potential Energy at the Maximum Height

The potential energy of an object at a certain height can be calculated using the formula:

Potential Energy = mass * gravity * height

Given that the mass of the object is 100 g (0.1 kg), the acceleration due to gravity is approximately 9.8 m/s^2, and the height at the maximum point is not provided, we cannot calculate the potential energy at the maximum height without this information.

Comparison of Kinetic and Potential Energies

Since we do not have the value for the potential energy at the maximum height, we cannot directly compare the kinetic and potential energies.

Calculation of the Sum of Potential and Kinetic Energies after 3 seconds

To calculate the sum of potential and kinetic energies after 3 seconds, we need to know the height at that moment. Unfortunately, the height is not provided, so we cannot calculate the sum of potential and kinetic energies after 3 seconds.

Conclusion

In conclusion, we were able to calculate the kinetic energy at the initial moment, which is 80 Joules. However, without the height at the maximum point and after 3 seconds, we cannot calculate the potential energy or the sum of potential and kinetic energies at those points.