Q: Fact 1: Afirecracker converts chemical energy into sound. Fact 2: Sound waves vibrate. Given the two facts above, a firecracker converts chemical energy into what?

Select from: - kinetic energy. - Loud noises. - vibrating waves. - An object is seen. - electromagnetic energy. - deoxyribonucleic acid. - hydrogen and oxygen. - harmful substances.
The answer is:
vibrating waves