How good is vacuum between the walls of vacuum flask?
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Alexander asked:
The gap between outer and inner walls of vacuum flask is 1cm.
The gap between outer and inner walls of vacuum flask is 1cm.
Before the flask was evacuated, the air between the walls was at normal pressure 100kPa and the flask was losing heat at rate 100W.
After air was evacuated and the flask was sealed, the flask is losing heat at rate 0.1W.
Assuming that all heat transfer is due to heat conductivity of residiul air only, ESTIMATE the pressure of residual air between the walls of the flask.
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