Answer to Question #259642 in Classical Mechanics for Tithi

Question

Miss Y agreed to keep a request from her friend to cook rice in an aluminium pot. A metal cover was used on the top of the aluminium pot during cooking, but after a short-while the metal cover was fallen down. They involved in a debate to explain it using a theorem of physics why the metal cover has been fallen down from the top of the aluminium pot. Miss Y said that it was due to produced pressure but her friend agreed on it to some extent and also asked about the conversion of energy, demanding to show the expression for the theorem. Could please help Miss Y?

Answer 1

Yes, the conservation of energy takes place: the energy of compressed air is used to increase the kinetic energy of the cover:

$$E_a=KE=\frac12mv^2.$$