When air is inflated into the basket ball then it means pump which is the system becomes warm.
Since work is done by the system and when pump is compressed then we are increasing pressure on air molecules inside it. Therefore, they will gain kinetic energy and this energy will be released in the form of heat.
Due to which the pump becomes warm.
Thus, we can conclude that a good hypothesis that could lead to new experimentation is that temperature of the pump is increased.
