When connecting a straight hose assembly, the minimum hose length should be calculated as:

The correct method for calculating the minimum hose length involves considering the potential for thermal expansion or contraction within the hose assembly, along with the installed and operational conditions of the system. The calculation typically incorporates a factor that accounts for these variations, which is represented in the formula by the term added to the base minimum length.

In this scenario, the choice that includes 50 + 50(0.05) accounts for a mid-range factor, accurately reflecting the necessary adjustments to accommodate the mechanical and thermal impacts on the hose. This is crucial in ensuring that the hose does not experience undue stress or strain during operation, which can lead to premature wear or even failure.

The factors in the other choices either overestimate or underestimate the required length for safe operation under normal conditions. For instance, a larger multiplier could result in an excessive hose length that may hinder installation or accord an unneeded amount of slack. Conversely, a smaller multiplier might not provide enough length to manage expected variations effectively. Thus, the correct calculation that involves a factor of 0.05 strikes an ideal balance for maintaining the safety and functionality of the hose assembly in various operational environments.