Final answer:
The proper name for the 12,000 psi value is allowable stress, denoted as σ_{allow}. Using the formula σ = F / A, we can calculate the required diameter of the aluminum guy wire to not exceed this stress under a load of 6,400 lb.
Step-by-step explanation:
The proper name for the value of 12,000 psi in relation to a guy wire for an antenna tower is called allowable stress and is often denoted as σ_{allow}. To determine the required diameter of an aluminum guy wire, we can use the formula for stress (σ) which is σ = F / A, where F is the force and A is the cross-sectional area. The cross-sectional area of a circular wire is given by A = π * (d/2)^2, where d is the diameter of the wire. Given an allowable stress of 12,000 psi and a maximum load of 6,400 lb, we need to find a diameter such that the stress does not exceed the allowable stress.
The steps are as follows:
- Convert the allowable stress to consistent units with the load, if necessary.
- Calculate the required cross-sectional area using A = F / σ_allow.
- Solve for the diameter d using the area equation A = π * (d/2)^2.
Carrying out these calculations will yield the minimum diameter necessary to support the load without exceeding the allowable stress.