If Q is load factor, S is shape factor and F is factor of safety in elastic design, the following: A. Q = S + F B. Q = S – F C. Q = F – S D. Q = S × F

The correct answer is D. Q = S × F.

The load factor is a multiplier that is used to account for the uncertainty in the load. The shape factor is a multiplier that is used to account for the variation in the strength of the material. The factor of safety is a multiplier that is used to account for the possibility of errors in the design.

The load factor, shape factor, and factor of safety are all multiplied together to obtain the design load. The design load is the load that the structure is designed to withstand.

The following is a brief explanation of each option:

• Option A: Q = S + F. This is not correct because the load factor and the factor of safety are both multipliers that are used to account for uncertainty. Therefore, they cannot be added together.
• Option B: Q = S – F. This is not correct because the load factor and the factor of safety are both multipliers that are used to account for uncertainty. Therefore, they cannot be subtracted from each other.
• Option C: Q = F – S. This is not correct because the load factor and the factor of safety are both multipliers that are used to account for uncertainty. Therefore, they cannot be subtracted from each other.
• Option D: Q = S × F. This is correct because the load factor, shape factor, and factor of safety are all multiplied together to obtain the design load.