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Yakk · 04-22-2004, 12:06 PM

Take a volume of water at 4 degrees celcius. This is the tempurature that water has maximium density (roughly).

Add in an ice cube that is -200 degrees celcius.

Note the water level.

The ice warms up, and the water cools down. Any size change in the ice cube won't change the water level. The water, however, will expand as it cools from 4 degrees towards 0 degrees.

The ice melting simularly won't change the water level.

Hence, if the water was 4 degrees at the start of the experiment, the jug would overflow.

If the water was higher than 4 degrees, and in melting the ice it didn't get colder than 4 degrees, the level of the water would drop.

If the water crossed 4 degrees, the result is indeterminate without more information.

If the ice melted without changing the tempurature of the water (say, the water was 0 degrees to start with, and the ice got the warmth out of the surroundings), then the level of the water would not change.

I believe the pressure comments are also equally indeterminate. The source of the pressure would be from the change in atmosphere above the jug or some other utterly neglidgable source.

However, on a physics test, the answer is b, unless you like including essays attached to multiple joice exams, or pointing out flaws in tests tot he prof during the exam.

04-22-2004, 12:06 PM	#24 (permalink)
Yakk Wehret Den Anfängen! Location: Ontario, Canada	Take a volume of water at 4 degrees celcius. This is the tempurature that water has maximium density (roughly). Add in an ice cube that is -200 degrees celcius. Note the water level. The ice warms up, and the water cools down. Any size change in the ice cube won't change the water level. The water, however, will expand as it cools from 4 degrees towards 0 degrees. The ice melting simularly won't change the water level. Hence, if the water was 4 degrees at the start of the experiment, the jug would overflow. If the water was higher than 4 degrees, and in melting the ice it didn't get colder than 4 degrees, the level of the water would drop. If the water crossed 4 degrees, the result is indeterminate without more information. If the ice melted without changing the tempurature of the water (say, the water was 0 degrees to start with, and the ice got the warmth out of the surroundings), then the level of the water would not change. I believe the pressure comments are also equally indeterminate. The source of the pressure would be from the change in atmosphere above the jug or some other utterly neglidgable source. However, on a physics test, the answer is b, unless you like including essays attached to multiple joice exams, or pointing out flaws in tests tot he prof during the exam. __________________ Last edited by JHVH : 10-29-4004 BC at 09:00 PM. Reason: Time for a rest. Last edited by Yakk; 04-22-2004 at 01:04 PM..