Question

In the previous chapter, a weightlifter is shown holding a barbell steady in her hands (Fig.). Is she doing any work on the barbell while holding it steady?

Answer 1

No, she is holding the barbell steadily without putting any effort into it.

Work done = Force × Displacement

The barbell does not move while it is being held steadily (s = 0).

∴ W = F × 0 = 0

Because her muscles exhaust her body's internal energy, she may feel worn out, but the work done on the barbell is nothing.