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a rock is thrown straight up from the surface of the earth. which one of the following statements describes the energy transformation of the rock as it rises? neglect air resistance.
both the kinetic energy and the potential energy of the rock remain the same.
the kinetic energy decreases and the potential energy increases.
the kinetic energy increases and the potential energy decreases.
both the potential energy and the total energy of the rock increase.
the total energy of the rock increases.

Explanation:

• Kinetic energy formula: \(K = \frac{1}{2}mv^{2}\). As the rock rises, its velocity \(v\) decreases (due to gravitational deceleration), so kinetic energy \(K\) decreases.
• Potential energy formula: \(U = mgh\). As the rock rises, its height \(h\) increases, so potential energy \(U\) increases.
• Total mechanical energy \(E=K + U\). Since there is no air - resistance (non - conservative force), by the law of conservation of mechanical energy \(E=\text{constant}\).

Answer:

The kinetic energy decreases and the potential energy increases.