Answer :
Without specific design information, codes, or tables relating to the material in question, it is not possible to determine the Unfactored Compressive unit stress, Fc, from just a slenderness ratio value of 56.3, hence the correct answer is option (a).
These resources typically provide tables or equations relating slenderness ratio to allowable stress. Without such specific design information or a proper formula, it is not possible to determine the compressive stress with a given slenderness ratio alone.
As the provided resources and references don't explicitly link to a specific value for Fc based on a slenderness ratio of 56.3, the correct answer cannot be determined from the given options of 39.4 ksi, 49 ksi, or 39.8 ksi. It's important to have access to the full context of the question, such as the material being used and the applicable codes or tables the slenderness ratio pertains to, in order to provide an accurate answer.
Understanding the concept of slenderness ratio is crucial in the design of columns and structural members as it impacts their load-bearing capacity and behavior under compression, influencing the appropriate selection of Unfactored Compressive unit stress. It should be noted that in engineering practice, such values would be determined using appropriate safety factors and design considerations unique to the specific application and regulatory standards in place.
Therefore, option a) it is not possible to determine is the correct answer.