HS - PS2.A (B) - Momentum - FINAL (WND 4/9/2014)

Module: Momentum

DCI: PS2.A (B) Momentum is defined for a particular frame of reference; it is the mass times the velocity of the object.

PE: HS-PS2-2 Use mathematical representations to support the claim that the total momentum of a system of objects is conserved when there is no net force on the system.

 [Clarification Statement: Emphasis is on the quantitative conservation of momentum in interactions and the qualitative meaning of this principle.] [Assessment Boundary: Assessment is limited to systems of two macroscopic bodies moving in one dimension.]

The ideas here are: 

- momentum can be defined for a particular frame of reference

- momentum is the mass times the velocity of an object

This particular batch will be followed up by one that will address the next portion of the DCI: 

• If a system interacts with objects outside itself, the total momentum of the system can change; however, any such change is balanced by changes in the momentum of objects outside the system. (HS-PS2-2),(HS-PS2-3)

So, for this batch, we will need to focus in on situations where the net force acting on a particular system is zero.  

We can do straight calculations, using the simple formula for momentum.  p = mv

In order to support the claim that the total momentum of a system is conserved, we might have to provide some data about the net forces acting on a pair of objects.