We will use this slow-motion video (Text description of Direct Measurement Video) to explore how and when we can apply conservation of linear momentum and conservation of kinetic energy to collisions. Our objective is to analyze a concrete example of how forces within a system affect conservation of kinetic energy and linear momentum during a collision. Specifically, we will:Define a specific system that is most useful for our analysis. Use the concepts of impulse and work to explore why internal friction forces affect the kinetic energy of a system, but not the linear momentum of the system. The event we will analyze is a heavy iron weight-lifting disk coming into contact with a rolling low-friction cart after it is dropped vertically onto the cart. After bouncing and sliding across the cart's surface, the disk comes to rest with respect to the cart's surface, and the disk and cart move together. To simplify and clarify this analysis, we'll consider the horizontal motion only. Would you predict that linear momentum and/or kinetic energy are conserved during this collision? Knowing when and how to apply the conservation laws for these two quantities is an important part of analyzing interactions between objects. Let's do some analysis of this interesting situation to see whether and why linear momentum and kinetic energy are conserved or not conserved.