Jan 26 2011
Air Celsius
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Air Celsius
I have a jug of water and a jug of milk, both at 40 Celsius, air temperature 10 Celsius, which cools quickest?
Its true that "rate of cooling" depends on "difference of temp" between sources (water/milk) and surroundings (air) - Newton's law of cooling??
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remember Newton's law works in the domain wherein "specific heat" is involved - for changing phase (ice>>water) - Law WAITS
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But Newton's law of cooling "says" THE SURFACE TEMP OF BODY" not the BULK Temp of body - internal dynamics excluded??
Now water/milk first form the outer temp of JUG by their their own internal dynamics of heat through their own "specific" heats.
water has the highest " specific heat" amongst all liquid/gases >> thus its thermal inertia (m*c) is highest to oppose any change in its own BULK temp whether while cooling or heating.
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that is the reason >>> lake gets frozen at the top due to (-20 C) air temp >> but beneath its water (successively, but very slowly) sheet-by-sheet converting into ICE. Thermal inertia
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in the jug >>> water will resist longer to drop off its (1 deg C) temp (BULK) than milk >>> thus milk will eventually LEAD the show of getting cooled faster.
RX-8 with K&N Air Filter Winter Time -11 celcius
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How many km is it to the coastal land if the air temperature is 20.0 degree's Celsius?
THE PROBLEM IS: A ship at sea sounds a whistle blast, and an echo returns to the coastal land 10.0 s later.
Do you mean from the coast? Because a return is to the place of origin, i.e. the ship.
So the land is 5.0 seconds away.
In dry air (obviously not the case here) and at 1 bar pressure, the speed of sound is 343 mps. Since we don't know the barometric pressure or the humidity, use this figure.
343*5=1715m round to 1700 (2 significant figures)
That's the best that can be done.
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