We need to calculate how much work it takes to lift a 160 N barbell.
The information we have is the weight (or gravitiy force) we have to apply to lift the barbell and the direction (upwards, 180 degrees from the direction of the weight).
As the work is:
[tex]W=\int F\cdot dx\approx F\cdot\Delta x[/tex]we are missing the displacement or distance (Delta x) we are lifting the barbell.
Answer: we need to know the value of the displacement in the lifting (Delta x)
