some intersting questions

[sar1281]

how the speed of aeroplanes is measured?
eventhough coccnut water is well surounded by shell what makes the noise when we shake the cocunut?
how to select refrigerants?(whetehr wate can be a refrigerent(economical compared to brine/gycol) for colling to (12C)

 

[quark]

SAR!

Skipped the first question.

Sound travels through anything except vacuum. When you shake a coconut vibrations created will cause sound and the sound passes through the shell and coir and to your ear.

Brine/Glycol are not generally called as refrigerants. They are cooling media. If your application is above 5 deg.C use soft water as cooling medium rather brine for specific heat of water is higher than any brine. (Note: freons are called refrigerants for example)

Regards,

 

[knobhead]

You can measure the spped of an aircraft with a pitot tube. Essentially it compares the static atmospheric pressure where the aircraft happens to be against the air pressure on the front of the aircraft as it flies, and calculates the speed from that.

There are other ways too.

Excessive accuaracy is a sign of poor breeding. -Socrates.

 

[IRstuff]

These days, GPS works pretty good for this sort of thing.

TTFN

 

[Prboz]

You talking air speed or ground speed? Just to put a spanner in the prop.

 

[vtl]

About the noise from the coconut.

Due to impact noise are created.