What qualifies as work in weightlifting
I'm in an introductory to mechanics course(calc based) and my class is in a chapter pertaining to work.
Now,
W=F*(Delta)r*cos(theta)
So work needs not only a force but a displacement
both the book and my professor go on to give examples like this
"Say you picked up a chair with one arm and held it in the air, with your arm completely straight and perpendicular to you body, for some time x; you are performing no work because while you are you applying force for some time x on the chair, the displacement of the chair in some time x is zero, so the work done is zero."
I understand the definition and the explanations due to the formula and I know minds much smarter than mine came up with this shit but I just have a hard time believing that when I see weightlifters hold 200kg+ bars over their heads for a few seconds and wait for the signal to drop the bar, that the lifters are doing no work.
Maybe I am missing something, maybe I'm not thinking hard enough on this...idk I just don't like it