Question

Internal energy does not include:
A. Vibrational energy
B. Rotational energy
C. Nuclear energy
D. Energy arising by the gravitational pull

Answer 1

The energy stored with a body is known as Internal energy. It depends on the chemical nature, temperature, pressure, and amount of substance. In other words, internal energy is the microscopic energy contained in a body resulting from the random disordered kinetic energy of Molecules.

Complete step by step solution:
If we closely observe molecular motion we see that in a gaseous state molecules show random motion nothing like solid and liquid state. On the other hand the molecules in solid and liquid exhibit vibrational and rotational motion. So the final energy of the system will contain a term for vibrational energy, rotational energy, and nuclear energy.
But the strength of the gravitational pull completely depends on mass since the mass of the molecules is almost negligible so it does not have a significant effect on the formation or motion inside molecules. Plus gravitational pull has the same effect on every molecule so it just becomes equivalent and the motion in molecules or systems with less mass gravitational pull is not a significant factor.
So the correct option is (D).

Note:
Gravitational potential energy and internal energy both are part of the conservation of energy but are specific physical phenomena.
In the plasma state, molecules have the highest internal energy. Plasma state can be determined by the superheated state of matter so hot that the electrons get ripped away from the atom and made an ionized gas.
In a system of absolute zero temperature, the system has the lowest internal energy in which the microscopic kinetic energy gives rise to the temperature of the system.