Conversion of one type of mechanical energy into another example.

In mechanics, there are only two types of energy: kinetic energy Ek – the energy of motion and potential energy En – the energy of interaction.
The kinetic energy Ek is determined by the formula: Ek = m * V ^ 2/2, where m is the mass of the body, V is the speed of the body.
The potential energy En is determined by the formula:
– for a body raised above the ground, En = m * g * h, where m is the mass of the body, g is the acceleration of gravity, h is the height of the body above the surface of the earth.
– for a deformed spring En = k * x ^ 2/2, where k is the stiffness of the spring, x is the absolute elongation of the spring.
1) The ball is thrown from the surface of the ground straight up. At the moment of the toss, the ball has only kinetic energy, since the height of the ball is zero. As the ball rises, its potential energy increases and the height above the ground increases. The kinetic energy decreases as the speed of the ball begins to decrease. Kinetic energy turns into potential.
At the highest point, the ball stops and has only potential energy, all kinetic energy has passed into potential.
When moving downward, potential energy is converted into kinetic energy.
2) When the spring is stretched, it has only potential energy, since we hold it, it has no speed. When released, potential energy begins to transform into kinetic energy. The absolute elongation begins to decrease, which means that its potential energy will decrease. In turn, the body begins to move, its speed increases, which means that the kinetic energy begins to increase. In the equilibrium position, all potential energy will be converted into kinetic energy. Further kinetic energy begins to transform into potential.