Answer:
<h2>A. The mechanical energy transforms to thermal energy as the pendulum slows and eventually stops moving.</h2>
Explanation:
The law of conservation of energy states that the amount of energy is a constant, that is, it cannot be created or destroyed, it just can be transformed into different forms.
For example, in real life, a pendulum will stop moving eventually. But, why is the pendulum going to stop? Because, there's friction in that motion, which means that the energy that's being used, it's transforming into heat by friction. In terms of energy, that heat represents a subtractor of the movement.
So, the mechanical energy, which is kinetic and potenial, it's transforming to "thermal energy", making the pendulum to slow down, until stops.
Now, in a perfect environment (which doesn't exist), the pendulum would never stop, and there weren'n any heat, because there wouldn't be friction. But that's not the case here.
Therefore, the best answer is A.
