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!

Around faucet handle is part of a(n) a. lever b. screw c. inclined plane d. wheel and axle

Athin plate moves between two parallel, horizontal, stationary flat surfaces at a constant velocity of v = 7.5 m/s. the two stationary surfaces are spaced 4 cm apart, and the medium between them is filled with oil whose viscosity is 0.9 n·s/m2. the part of the plate immersed in oil at any given time is 2 m long and 0.5 m wide. if the plate moves through the mid-plane between the surfaces, determine the force required to maintain this motion. what would your response be if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top surface (h1)? if the plate moves through the mid-plane between the surfaces, the force required to maintain the motion will be n. if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top (h1) surface, the force required to maintain the motion would be n.

You have a pick-up truck that weighed 4,000 pounds when it was new. you are modifying it to increase its ground clearance. when you are finished