Alam Sekitar dan Perubahan Cuaca - Akademi Sains Malaysia

32Jun2009Warm ai rWhatyou'll need:• Empty bottle• Balloon• Pot of hot water(not boiling)needs more roomAs its temperature rises, air starts to act a bitdifferently. Find out what happens to a balloonwhen the air inside it heats up.Stretch the balloon over themouth of the empty bottle.Put the bottle in the pot of hotwater, let it stand for a few minutesand watch what happens.As the air inside the balloon heats up it starts toexpand. The molecules begin to move faster andfurther apart from each other. This is what makesthe balloon stretch. There is still the same amountof air inside the balloon and bottle, it has just expandedas it heats up.Warm air therefore takes up more space than thesame amount of cold air, it also weighs less thancold air occupying the same space. You might haveseen this principle in action if you've flown in orwatched a hot air balloon.