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A 75.0-kg person climbs stairs, gaining 2.50 meters in height. Find the work done to accomplish this task. (Neglect friction in your calculations.)

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Solution:

Work done against gravity in lifting an object becomes potential energy of the object-Earth system. The change in gravitational potential energy is $\Delta PE_{g} = mgh$, with $h$ being the increase in height and $g$ the acceleration due to gravity.

We are given the following values: $m=75.0\ \text{kg}$, $g=9.80\ \text{m/s}^2$, and $h=2.50\ \text{m}$.

Substitute the given in the formula.

The work done is about $1.84 \times 10 ^ {3}\ \text{Joules}$.

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