Answer:
He does 20601 J of work
Explanation:
Step 1: Data given
Mass of the firefighter = 75.00 kg
Height of the stairs = 28.00 meters
Step 2: Calculate the work done
The work required = difference between the final potential energy (Uf) and initial potential energy (Ui)
The work required = Uf - Ui
⇒ with Uf = m*g*h
⇒ with Uf = 75 *9.81 * 28 = 20601 J
⇒ Ui = 0 J when we take initial height, h = 0 J
The work required = Uf - Ui
Work required = 20601 - 0 = 20601 J
He does 20601 J of work