Afootball player pushes against another player trying to block him from moving any farther down the field. which term best describes this example? milar you would want to mention that

The fotball player is creating a negative work (in the system of the other player)

this means that, if the other player wants to move forward, he first needs to "cancel" the work that is beign done in him (he can do this doing more force on the other player, so the work that he does in the other player is bigger, and now he has positive work, so he is moving).

at right angles to each other