At rest because if the distance is not changing, then it is not moving any further, so it must not be moving! The time keeps going no matter what, so the distance, whether it is 0 m or 10,000 km, if the y is horizontal the distance does not change.
Answer:
Thermal energy of an isolated system changes with time If the mechanical energy of that system is constant according to the first law of thermodynamics, which states that thermal energy of an isolated system can still change as long as the total energy of that system does not change.
Explanation: