12 POINTS! - Sam turns his bicycle upside down and turns the pedals fast so that the back wheel spins.
Sam holds a piece of card close to the back wheel. The spokes (metal lines) hit the piece of card and Sam hears a musical tone.
Explain why the card produces a musical tone.

When the spokes hit the piece of card, the wheel slows down.
Describe the energy change which occurs as the wheel slows down.

Describe and explain what will happen to the pitch of the musical tone as the wheel slows down.


If you don't understand the question then please do not put a random answer for points. Thank you!