Question

A cran uses an average force of 5200N to lift a steel beam 25m. How much work does the crane do on the steal beam.

Answer 1

The work done by a force is  given by:
$W=Fd \cos \theta$
where
F is the magnitude of the force
d is the distance covered by the object
$\theta$ is the angle between the direction of the force and the direction of motion

In our problem, $F=5200 N$, $d=25 m$ and $\theta=0$ (because the force is parallel to the direction of motion), so the work done by the crane is
$W=(5200 N)(25 m)(\cos 0^{\circ})=1.3 \cdot 10^5 J$