Final answer:
A "strong back" is used in construction to provide additional support and prevent excessive deflection or sagging in structures like trusses and floor joists.
Step-by-step explanation:
A "strong back" would be used in construction, specifically in the context of building structures like trusses and floor joists.
A strong back is a reinforcing member that is placed on top of the truss bottom cords or floor joists to provide additional support and prevent excessive deflection or sagging.
For example, when constructing a truss, a strong back is installed on top of the truss bottom cords before sheathing is applied, ensuring that the truss system remains structurally sound.