Final answer:
Building codes often determine the load a guard or handrail must withstand; it is not specified in the provided context, but is important for safety and adherence to local regulations.
Step-by-step explanation:
The design strength of a guard should resist a force adequate to ensure safety and comply with building codes. Typically, in construction and engineering, a guard like a handrail should withstand a substantial load applied at any point to prevent failure due to excessive force. The exact value of this force is codified in local building regulations but often falls within a range that considers the potential forces that could be exerted by people leaning or falling against the guard.
When assessing forces in a static or dynamic situation, it is crucial to consider the direction of the applied force and the magnitude of the force. In the context provided, if a concentrated load is applied along a handrail or on top of a guard, it is essential to ensure that the guard's design strength can withstand such a load without failure.