Answer:
the torque on the joint at the main stem is increased as the person moves toward the end of the branch, as is the stress within the branch.
Explanation:
In general, a branch will break when its load limits are exceeded, and/or when the stress is applied at a rate that exceeds its ability to accommodate.
Two things happen when a person moves toward the end of a tree branch:
- the torque on the branch joint is increased due to the increased moment arm
- the stress in the branch is increased because the branch gets smaller
So, if the branch doesn't break due to increased stress within the branch, the joint may fail due to its torque limit being exceeded as a person moves closer to the end.
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From an engineering point of view, the stress limits constitute a threshold that will result in breakage with probability 1 when exceeded. When the limits are far above the applied stress, the probability of breakage is near 0. So, one could say the probability increases when the person approaches the end of the branch, since it goes from near 0 to 1.
