Chapter 6, Problem 1P

A 75.0-kg firefighter climbs a flight of stairs 28.0 m high. How much work does he do?

To determine

Work done by a firefighter.

Answer to Problem 1P

Solution:

20580 J

Explanation of Solution

First, force can be calculated which is needed to apply on a flight than work done by the firefighter.

Given:

Mass of the firefighter, m=75 Kg. The height of stairs, h= 28 m.

The formula used:

$\text{F=ma}$

Where “F” is the Force required to climb the stairs

“m” is the mass of the firefighter

“a” is the acceleration or gravity force (9.8 m/s²)

$W=Fd$

Where “F” is the Force required to climb the stairs

“W” is the work done by the firefighter

“d” is the height.

Calculation:

Force required to climbing the stairs

$F=ma$

$F=75\times 9.8$

$F=735\text{ N}$ ---------------(1)

Work done by the firefighter

$W=Fd$ -------------------(2)

By using equation (1)and (2)

$W=735\times 28$

$W=20580 \text{J}$