Momentum What is momentum and how does it affect moving objects? Starter: Which of these is the hardest / easiest to stop. Give reasons for your decisions. Learning outcomes Know the equation for momentum. Newtons cradle This shows the law of conservation of momentum. In a closed system the total momentum before the event is the same as the momentum after the event. i.e. momentum at beginning is same as at the end. A demonstration of momentum. Crashing trolleys. Gun recoilWNBkHMhttp://www.youtube.com/watch?v=_S8Fh WNBkHM How does this show conservation of momentum? 1min 15 Momentum what could the equation be? Momentum (kg m/s) = __________x___________ Momentum Momentum (kg m/s) = mass (kg) x velocity (m/s) Momentum is NOT A force Think Pair Share: Order the cards in terms of highest to lowest momentum. Its a momentum race! Dougie has a mass of 67kg and is moving at 23m/s. What is his momentum? Danny is on a motorbike with a momentum of 650 Kg m/s. His mass is 71kg, what is his velocity? Tom is moving at 5 m/s along a motorway in his new car. The car has a momentum of 200kg m/s. What his Toms mass? Harry is moving his drum kit at 0.5 m/s. The drum kit has a mass of 85kg, what is the momentum? A tour bus is moving with a speed of 3 m/s. The overall mass is 4320kg. What is the momentum of the tour bus? A tour bus is moving with a speed of 3 m/s. The overall mass is 4320kg. What is the momentum of the tour bus? 5 mins Complete the questions on momentum. Task Write 5 momentum questions of your own, and produce a marking scheme. Swap with neighbour, complete their questions and WWW/ EBI them. Force and Change in Momentum Why is momentum important in car design? Starter: Why are people killed in car crashes? Learning Outcomes demonstrate that the change in momentum depends on the size of the force and the time for which it acts explain that change in momentum (kg m/s) = resultant force (N) time (s) Think Pair Share: Would you be safer in Car A or Car B ? Crumple Zones Clever Car Design If you go from 70-0 mph too fast then the change in momentum from high to 0, means a massive force is transferred to your body. change in momentum (kg m/s) = resultant force (N) time (s) THINK PAIR SHARE how are cars designed to reduce this force? Lets go outside! (Assuming it isnt raining) https://www.o2learn.co.uk/o2_video.php?v id=1575https://www.o2learn.co.uk/o2_video.php?v id=1575 Crumple zones Crumple zones are designed to reduce the forces that hit your body by allowing the momentum into the car rather than you. Task Design and build a crumple zone that will protect a passenger/an egg. 6 mark question Use the idea of momentum to explain why cars are built with crumple zones.