Question

Suppose you are swimming forward in a swimming pool with butterfly stroke. The work done is.

• A. zero
• B. non-zero
• C. $\infty$

Answer 1

The correct option is B non-zero

While swimming you are applying force on water and water is applying an equal force on you in opposite direction. The work done is zero only when the angle between force and displacement is ${90}^{\circ }$. In this case, the direction of force is definitely not perpendicular to the direction of displacement. Hence work done is non-zero.