Gr.7 Science Final Revision Sheet- Term 3

The thicker strings of the guitar have a lower frequency, and therefore a lower pitch, than the thinner strings.

An echo is an example of sound diffraction.

Any material with a porous surface can act as a sound absorber.

The characteristics of the medium have an effect on the speed of the sound waves traveling through them.

look at the picture. There are 4 sound waves with different amplitude and frequency. Which sound wave has highest pitch? Why?

What is this phenomenon?

Pulling opposite charges away from each other decreases the potential energy of the system.

The continuous flow of charge is referred to electric potential.

Circuits provide paths for current to flow in a loop.

Charges flow through a circuit due to differences in potential energy.