Mass is how heavy is it, weight is the size both are the same
In this case, the air from the warm area will always start moving towards the colder areas because as the temperature in both lands should be equal. This is one of the laws of thermodynamics.
this is due to the existence of other forces called the strong nuclear forces that overcomes the repulsion forces between the protons and keeps the nucleons holding to each other also there is a type of energy that is called the nuclear binding energy and this energy also works on binding the components of the nucleus together
Given:
The thermal energy added to the system is Q = 90 J
The work done by the system on the surroundings is W = 30 J
To find the change in internal energy.
Explanation:
According to the first law of thermodynamics, the change in internal energy can be calculated by the formula

On substituting the values, the change in internal energy will be

Final Answer: The chage in internal energy is 60 J (option D)