Which of the following is not an example of work?

A.
raising a barbell over your head

B.
picking up a box off the floor

C.
holding a tray in the cafeteria line

D.
pushing a box across the floor

I think its C.

3 answers

Force times distance in direction of force

If not moving in cafeteria line - no work
If moving forward in line and weight of tray is down, force not in direction of motion --> NO WORK
So yes, C
Ty :)