An object is horizontally dragged across the surface by a 100 N force acting parallel to the surface. Find out the amount of work done by the force in moving the object through a distance of 8 m.

Work is done when a force acts upon an object to cause a displacement.
Work(W) = Force(F) x Displacement(s)

$\mathrm{W} = \mathrm{Fscos\theta }$
Where θ is the angle between force and displacement.

From the question we have,
Force(F) = 100 N
Displacement(s) = 8 m
θ = 0 ° (Force and displacement happening in the same direction)

So, the work done is,
$\mathrm{W} = \mathrm{Fscos\theta }$    
$\mathrm{W}= 100\times 8\times \cos 0 °$
$\mathrm{W} = 800\times 1 = 800 \mathrm{J}$

Therefore, the work done will be 800 J.