Answer:
A hot air balloon uses a burner to heat up the air inside the balloon. The burner is usually fueled by liquid propane. The burner mixes the fuel with air and ignites the mixture, which creates a flame directly underneath the bottom opening of the hot air balloon. Once the air inside the balloon begins to get warm, the balloon will rise. The pilot controls the balloon’s altitude by releasing hot air from a vent at the top of the balloon, releasing the warmer air causes the balloon to descend.
Step-by-step explanation: