Final answer:
A lawn mower gains energy when work is done by applying a force that moves it, resulting in mechanical energy. It loses energy due to friction, air resistance, and wear and tear. Energy is required to overcome the inertia when the mower is started.
Step-by-step explanation:
The question seems to be based on the topic of work and energy in physics. A lawn mower gains energy when the person operating it applies a force to move it, causing the mower to do work on the grass. The energy can be in the form of mechanical energy, which includes both kinetic energy (while the mower is moving) and potential energy (if it's moving up an incline).
Conversely, a lawn mower would lose energy due to various factors such as friction with the grass and air resistance. Over time, wear and tear on the mower's parts can also lead to a loss of energy efficiency. Additionally, when the mower is turned off and sits without motion, it doesn't gain or lose energy, but when turned on again, it must consume energy to overcome the inertia to start moving.
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