Q This assignment supports the following Unit Objectives: • (U70) Define momentum (CLO2)(CLO4) • (U71) Apply the definition of momentum (CLO2)(CLO4) • (U72) Calculate momentum (CLO2) • (U73) State and apply the Law of Conservation of Momentum (CLO2)(CLO4) • (UDS) Develop a well thought out and correct response to various discussion questions(CLO2)(CLO4)(Goal 4) Do not start a new thread. Simply reply to my posting. Be sure to comment on at least two of your classmates' postings. Your replies must be more than a simple phrase like "I agree" or "I like your answers". Replies should reflect on why you agree or like what has been posted. Your replies must reflect a genuine effort to engage your fellow classmates regarding the comments provided or the problem that has been solved. Please post your responses here. 1. The momentum of the universe is always conserved, but the momentum of any observable system on Earth typically is not. Name two forces that are common external forces acting on a given system at any time. 2. Show how the impulse-momentum theorem (Ft = (delta)p) is simply a rewrite of Newton's 2nd Law (F = ma) where the mass of the system is not required to be constant. 3. Why are "real" collisions not elastic? 4. A common error in thinking arises from the examination of car crashes. A car crashing into a wall at 50 mph experiences the same force as a car in a head on collision with a car of equal mass when both are driving 50 mph. Using momentum, explain why the head on collision is not equal to a collision with a wall at 100 mph. (**There's a Mythbusters episode where they examine this very phenomenon and of course destroy some cars in the process.)