Hey guys, I'm trying to complete a homework problem, but I'm not quite sure how to approach it. Here is the question: A 90.5-kg fullback running east with a speed of 4.91 m/s is tackled by a 94.7-kg opponent running north with a speed of 2.93 m/s. Determine the mechanical energy that disappears as a result of the collision. This question actually came after the question that read: Calculate the velocity of the players immediately after the tackle. I solved that problem with the value of the magnitude being 2.83 m/s and the value of θ = 32.0°. Now I know that in the book, they say that E_mech = K + U (kinetic energy and potential energy), but I don't quite know how to calculate the lost mechanical energy. Any pointers of how the process would go would be appreciated! Thanks!