Hail

[Jonathan Jarvis]

It has just hailed where I live.

I noticed a phenomenon which I cannot understand. The hail bounced higher on my lawn than on the concrete path.

I would have thought that the hail would bounce higher on a hard path surface than on a soft grass surface which would absorb the impact.

Any thoughts anyone?

 

[Chesterton]

Well if the grass is thick it's probably got some flexibility/springiness to it. Maybe?

 

[Jonathan Jarvis]

My grass and the neighbours are different lengths (mine is longer) but the bounce height was about the same.

 

[PsychoSarah]

My grass and the neighbours are different lengths (mine is longer) but the bounce height was about the same.

I imagine that the difference in the length of your grass wouldn't make as much of a noticable difference as between concrete and grass. and you can see the hail bounce easier when it has a contrasting color like green rather than a bunch of concrete.

 

[Jd34]

I would imagine that hail hitting the hard surface of concrete would break some, therefore ,expending some kinetic energy limiting rebound as opposed to the soft flexible surface of grass yielding more energy for rebound. That is, if hail in fact rebounds higher in grass than on concrete...

 

[keith99]

Hail is a very soft form if ice. When it strikes concrete it deforms or even shatters. Grass however cushions that effect and then springs back.

Also after a little while the concrete will have a layer of water and hail that will cushion, but not bounce back.

I suspect that in very cold environments this effect will be greatly reduced, perhaps even reversed.