Question

A 75.0-kg person climbs stairs, gaining 2.50 m in height. Find the work done to accomplish this task.

Answer 1

Answer:

$W=1837.5J$

Explanation:

A force exerts work when there is a displacement of its point of application in the direction of that force. Therefore, the work done by a system is defined as the inner product between the applied force and the displacement:

$W=\vec{F}\cdot \vec{d}\\W=Fcos\theta d$

In this case, we have:

$F=mg\\h=dcos\theta$

So, replacing this:

$W=mgh\\W=75kg*9.8\frac{m}{s^2}*2.5m\\W=1837.5J$