500
A mobile turns from a candle burning below it. Explain HOW the heat causes the mobile to turn. (You must state details, not just the heat transfer method.)
As the energy from the burning candles heats the air above them, the air particles move faster. The particles move farther apart as they take in the energy. This makes the air less dense. Cooler air rushes under the less dense air. It pushes the warmer air upward. As long as the candles—the heat sources—are burning, movement of the rising warm air will make the spiral twirl and the blades spin.