Internal energy is the sum of ke and pe of all the molecules.Internal energy can increase in the temperature increase(ke increase) or potential energy increase (molecules further apart)or more molecules present(N) .
Question in sample paper TYS pg 45.
16. The random ke of all the gas molecules inside a tyre of an aircraft is 63 kJ .
The translational ke of these molecules is 10 kJ.
The random pe of the molecules is - 2 kJ .
The pe due to the height of the aircraft is 4 kJ.
What is the internal energy of these molecules?
The internal energy of the molecules = ke (random) + Pe (random)= 63kJ + (-2kJ)= 61kJ
Table found on page 111 Q33 gives a clear information about ke , pe and internal energy of solid liquid and gas at different temperature. Temperature the same gives the same ke.
