At a 70-degree climbing angle, what percentage of the ladder's total length is lost?

When a ladder is placed at an angle to the ground, its effective working length is diminished due to the angle of elevation. At a 70-degree climbing angle, the loss of usable ladder length can be calculated through trigonometric principles.

The height that can be reached with the ladder is determined by the sine of the angle of elevation. As the angle increases, the sine value approaches 1, meaning that a larger portion of the ladder's total length remains usable. However, at 70 degrees, the sine value is approximately 0.94. This indicates that around 94% of the ladder's length is effective in reaching vertical height.

To find the percentage of ladder length lost, one can subtract this effective percentage from 100%, leading to the conclusion that roughly 6% of the ladder’s total length is lost when it is set at a 70-degree angle. This is why the choice indicating a 6% loss is correct, as it accurately reflects the trigonometric relationship between the climbing angle and the effective length of the ladder.

Understanding these concepts is crucial for fire officers and personnel who must utilize ladders effectively in emergency situations, ensuring both safety and efficiency in their operations.