Final answer:
To spray the exterior of a home, adjust the backpack nozzle to a fan spray for wider and more uniform coverage. The fan spray utilizes the expansion of compressed air and energy input to ensure an even application.
Step-by-step explanation:
When spraying the exterior of a home, you would likely want to adjust your backpack nozzle to a fan spray setting. This setting is ideal because it provides a wider coverage area which ensures a more uniform application. The principles behind the dispersal pattern relate to the expansion of compressed air from the canister into the atmosphere, helping to spread the spray evenly. Additionally, the input of energy is necessary to overcome intermolecular forces, contributing to the even dispersal of the spray. The nozzle of the canister may feel cold due to the endothermic process where the molecules absorb energy from their surroundings, including the canister, as they exit and expand.