Wigton Drip 2

I spotted a regular drip from a gutter that was producing concentric ripples in the puddle below.

I put my foot into the frame for scale and used the multi-shot function on my camera. The wavelength is about the width of my foot so let's say 10cm.

These are two consecutive frames. It's hard to tell but I think the wavefronts have advanced about 1cm.

To find the time between two consecutive frames, I photographed a watch.

The first frame is a above and the sixth frame is below. It took 5 frames to go 1 second so let's say the time for 1 frame is 0.2 seconds.

If the wavefront advances 1cm in 0.2 seconds, the wave speed is 5 cm per second. Now frequency = wave speed / wavelength = 5/10 = 0.5 Hz or one drip every 2 seconds.