Question

In a tug of war, the team that exerts a larger tangential force on the ground wins. Consider the period in which a team is dragging the opposite team by applying a larger tangential force on the ground. List which of the following works are positive, which are negative and which are zero? 

(a) work by the winning team on the losing team 

(b) work by the losing team on the winning team 

(c) work by the ground on the winning team 

(d) work by the ground on the losing team 

(e) total external work done on the two teams.

Answer 1

(a) Positive 

(b) Negative 

(c) Zero (Assuming that work by ground means work by frictional force by ground, Also assuming the winning team does not step backwards) 

(d) Negative (Assuming that work by ground means work by frictional force by ground, Losing team is dragged) 

(e) Zero (Taking rope, both teams and ground as a system, no external force is on the system, so no external work done)