1. Momentum and Impulse By Christos Hadjichristidis

2. Momentum in every day life “The momentum brought Sunderland the lead after 67 minutes. Marcus Stewart, their most influential player, crossed from the left and Kyle's lunging header beat Gerrard at his near post.” Sport Telegraph 3/10/2004(Sheff Utd 0 Sunderland 1) Thus, the greater the momentum of a team the harder it gets to be stopped.

3. Momentum in Physics In physics momentum is defined as the quantity of a motion that an object posses. This depends only on “how much stuff is moving” and “how fast the stuff is moving. In other words: Be careful momentum just like velocity is a vector quantity; in order to be fully defined both its magnitude and direction should be given

4. Momentum is directly proportional to both mass and velocity of an object; Both variables are of equal importance in determining the momentum of an object Consider the following example: – A car weighting 1tonne that travels with a speed of 20 m/s and Dave riding his Ducati (mass Dave+Ducati=300Kg) at the legal (for Germany) speed of 83m/s. Guess who has the greatest momentum. (does the weight of the car driver matters?)

5. How momentum changes? In order to stop an object that posses some momentum we have to exert a force against its motion for a period of time. Thus, it would require a greater amount of force or a longer amount of time (or both) to bring an object with more momentum to a halt. In general, in order to change an object’s momentum one has to exert a force to it for a given time. That will change the velocity of the object; but change of velocity means change of momentum too. The amount of the change in momentum depends upon both parameters:

6. The time for which the force acts does matter Force TimeImpulse 1001 502100 254100 10 100 425100 250100 1 0.11000100

7. Conservation of Momentum Lets consider a collision between two objects in an isolated system. (Isolated is a system upon which no external force acts). We know that in a collision between two objects, both objects experience forces which are equal in magnitude and opposite in direction. We also know that the interaction time is the same for both objects

8. Solving collision problems Before Collision (kg*m/s)After Collision (kg*m/s) Granny 80 * 6 = 48080 * v Ambrose 040 * v Total 480

9. Solving Problems in General READ the problem carefully CONSTRUCT a sketch IDENTIFY the known quantities and isolate the ones that you were supposed to find.(Probably by constructing an known-Unknown table). TIP: The number of the equations needed to solve the problem is defined by the number of your unknowns. THINK of relevant equations you should use. In our case you could use one or more of the following:

10. In Conclusion Every moving object posseses a momentum : Momentum is conserved unless a force is applied upon the object for a given time. The change of momentum that the force is causing during this time period is: Collisions of objects within an isolated system could not change the total momentum of the system:

11. http://physics.weber.edu/amiri/director/dcrfi les/momentum/carCrashS.dcr http://physics.weber.edu/amiri/director/dcrfi les/momentum/carCrashS.dcr