What is the work done if we apply a 1.2N force and we move 4 meters in the direction of force?
This question can be solved by using the equation that Work = Force x Distance.
The force provided is 1.2 Newtons and the distance moved is 4 meters.
Work = 1.2 x 4
Work = 4.8 Joules
A Joule is the unit for work, and it is equivalent to one Newton of force causing a movement of one meter.
What's interesting about work is the fact that a distance of movement must occur in the direction of the force for work to have been done. Mathematically, it looks simple.
Work = 50 N x 0 meters
Work = 0 Joules
Mathematically, that looks completely legitimate; however, there are some frustrating examples of forces doing zero work. I like to demonstrate by having a student push against my classroom wall as hard as they can for 30 seconds or so. Students are shocked to find out that despite being tired, they did zero work. The wall didn't move.