(a) Work by the winning team on the losing team is positive, as the displacement of the losing team is along the force applied by the winning team.(b) Work by the losing team on the winning team is negative, as the displacement of the winning team is opposite to the force applied by losing team.(c) Work by the ground on the winning team is positive.(d) Work by the ground on the losing team is negative.(e) Total external work on the two teams is positive.