Answer to Question #259307 in Classical Mechanics for Light Fury

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

Alright, conservation of energy explains why it fell down:

$$\Delta KE=PE,\\ KE_2-KE_1=PE,\\ KE_1=0,→KE_2=PE.$$

As we see, the cover fell because it had a potential energy.