What formula is used to determine stress on a snatch block performing a vertical lift?

The correct formula used to determine the stress on a snatch block performing a vertical lift is based on the line pull and the block factor. The line pull is the force exerted along the rope, while the block factor accounts for the mechanical advantage that the snatch block provides. By multiplying the line pull by the block factor, you calculate the block load, which reflects the actual load exerted on the snatch block due to the lift.

Understanding this concept is crucial in rigging, as it helps ensure safety and efficiency when lifting loads. The other options do not correctly relate to the calculation of stress on a snatch block in a vertical lift context. For instance, calculating total load by multiplying block load by lift height does not accurately assess stress but rather measures other characteristics of the lift. Similarly, relating load weight to boom angle or adding the weight of the load to boom length does not constitute a valid method for calculating stress on a snatch block.