Question

What is the work done by a 25 kg boy when he runs up a flight of stairs 13 m high? A) 1.92 JB) 3250 J C 162.5 J D) 81.3 J

Answer 1

In order to calculate the work done, we can use the formula below:

$W=F\cdot d$

Where W is the work done (in J), F is the force (in N) and d is the distance (in m).

Since the boy is going up the stairs, the force is equal to his weight force:

$\begin{gathered} F=m\cdot g\\ \\ F=25\cdot10=250\text{ N} \end{gathered}$

Now, calculating the work, we have:

$\begin{gathered} W=250\cdot13\\ \\ W=3250\text{ J} \end{gathered}$

Therefore the correct option is B.