More Work-Energy Problems Video Lessons

Example

# Problem: A fireman of 80 kg slides down a pole. When he reaches the bottom, 4.2 m below his starting point, his speed is 2.2 m/s. By how much has thermal energy increased during his slide?

###### FREE Expert Solution

Change in thermal energy:

$\overline{)\begin{array}{rcl}\mathbf{∆}\mathbf{T}\mathbf{E}& {\mathbf{=}}& \mathbf{P}\mathbf{E}\mathbf{-}\mathbf{K}\mathbf{E}\\ & {\mathbf{=}}& \mathbf{m}\mathbf{g}\mathbf{h}\mathbf{-}\frac{\mathbf{1}}{\mathbf{2}}\mathbf{m}{\mathbf{v}}^{\mathbf{2}}\end{array}}$

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###### Problem Details

A fireman of 80 kg slides down a pole. When he reaches the bottom, 4.2 m below his starting point, his speed is 2.2 m/s.

By how much has thermal energy increased during his slide?