Momentum:
- Its the product of mass and velocity
- It is represented by a capital P
- Can be conserved if no external forces act on it
- It is a vector so it does have direction and magnitude
- The unit for momentum is kilogram meter per second kg⋅m/s
- The change of momentum is impulse
- Impulse is a change of force over time
- On a force vs time graph impulse is represented by the area under the line
- The equation for impulse is FΔt= J
- since momentum is mass x velocity and impulse is the change of velocity, impulse can be represented as mΔv
- unit for impulse are Newtons times seconds or kilogram meter per second kg⋅m/s
Collisions:
- Perfectly inelastic
- Conserved momentum but kinetic energy is lost. This is also a situation when objects hit and stick together
- Inelastic
- Momentum is conserved but kinetic energy is lost
- Perfectly Elastic
- kinetic energy is conserved and so is momentum. The objects will hit and bounce off each other
- Elastic
- This is when momentum and kinetic energy is conserved but the objects don't stick together.
- Explosive:
- Momentum is conserved and kinetic energy increases. This is the situation where objects start touching each other but then explode by separating from each other,
Most of our equations are going to work with the concept of conservation of momentum. This sounds like it is states, momentum is conserved in a system. A key term to know for this would be center of mass. This is the unique point in which the relative weight distributed would sum to zero and if a force is applied at the point it will cause it to linearly accelerate rather then angularly distribute.
Momentum bar charts (LIL charts)
- Something new that is learned in this unit is LIL charts or momentum bar charts. They are used to represent momentum and impulse which show the conservation and change in momentum from initial to final quantities.