Pressure Pressure (P) can be defined as a force (F) acting on a given area (A);
P = F/A
Temperature Temperature (T) is the intensity of heat in a substance and may be measured on the graduated scale of a thermometer.
Volume Volume (V) refers to a space occupied in three dimensions.
Vacuum As a practical definition, any environment in which the pressure is lower than atmosphere may be referred to as a vacuum.
The lunar day and night are 14 days each.
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