4.2a Everyday events involve one form of energy being changed to another.

•animals convert food to heat and motion

•the Sun ’s energy warms the air and water

4.2b Humans utilize interactions between matter and energy.

•chemical to electrical, light,and heat: battery and bulb

•electrical to sound (e.g., doorbell buzzer)

•mechanical to sound (e.g., musical instruments, clapping)

•light to electrical (e.g., solar-powered calculator)