Problem 14

Given information

Definition of Energy.

Energy is the ability to perform work. Energy can nor be made nor destroyed, and it must be changed starting with one structure then onto the next.

Step-by-step explanation

Find the fallen log in their path rather than stepping on top and stepping down on the other side.

Stepping on the log requires that the entire body mass be raised up the height of the log, requiring work (that is not recoverable) proportional to the entire body mass. Stepping over the log only requires the raising of the legs, making for a small mass being raised and thus less work. Also, when jumping down, energy is expended to stop the "fall" from the log. The potential energy that you had at the top of the log is lost when coming down from the log.