Demonstrate diffraction in a ripple tank

[Cheman]

When we demonstrate diffraction in a ripple tank, why does shallower water slow the passage of the water wave down?

Also, are there any other ways to demonstrate when refraction happens without light nor water waves?

Thanks.

 

[compute_a_nerd]

according to my physics book. When the water is coming into shore, or becoming more shallow it slows down because the water is actually dragging on the bottom. Is this correct?
I was thinking that when the water gets more shallow that the frequency increases, and the wavelength decreases. but the equation $$v = \lambda f$$, wouldn't this show that velocity stays the same?

Thanks

 

[Graeme Robinson]

Diffraction is the bending of waves around obstacles or through openings. When we demonstrate diffraction in a ripple tank, we can see this phenomenon by creating waves in the tank and observing how they change direction as they pass through a narrow opening or around a barrier.

The reason why shallower water slows down the passage of water waves is due to the change in the wave's velocity. In shallower water, the waves have less depth to travel through, causing them to slow down. This change in velocity causes the waves to bend or diffract more as they pass through openings or around barriers, making it easier to observe diffraction in shallower water.

As for other ways to demonstrate refraction without light or water waves, one example could be using sound waves. Sound waves also experience refraction when they pass through different mediums with varying densities. An experiment could be set up to demonstrate this by using a speaker to create sound waves and observing how they change direction when passing through different mediums, such as air and water. Another way could be using seismic waves, which are generated by earthquakes, to demonstrate refraction in the Earth's layers.

Overall, diffraction and refraction are fascinating phenomena that can be observed in various ways, and understanding them is crucial in many fields such as physics, optics, and geology.