Let the change in total kinetic energy in this collision be defined by \Delta K=K_{f}-K_{i}, where K_{f} is the total final kinetic energy, and K_{i} is the total initial kinetic energy. Which of the following is true?
Answer Choices
A. \Delta K=\left(K_{i}+K_{f}\right) / 2
B. K_{f}<\Delta K<K_{i}
C. 0<\Delta K<K_{f}
D. \Delta K=0
E. -K_{i}<\Delta K<0