U4AOS1 Topic 7: Wave Speed

Waves always propagate at a constant speed in a constant medium.

The speed of a wave does not change as long as it travels in the same medium.

Waves travel at a speed of $\mathrm{<span\; style="font-size:\; 14px;">3</span>}\mathrm{<span\; style="font-size:\; 14px;">4</span>}\mathrm{<span\; style="font-size:\; 14px;">0</span>}\mathrm{<span\; style="font-size:\; 14px;">m</span>}\mathrm{<span\; style="font-size:\; 14px;">/</span>}\mathrm{<span\; style="font-size:\; 14px;">s</span>}$340m/sin air. Regardless of the amplitude and frequency of the wave. So remember if it says it travels in air then the speed is fixed.

This means that the following relationship will always apply.

$v = f\lambda = \frac{\lambda}{T}$

Where v is the velocity and f is the frequency of the wave.

It's important to remember that λ and f are proportional. This means if one increases then the other will decrease.