Question

1# What is the conservation of momentum? Under what conditions is it true?

During the upcoming lab you will work as a class to test predictions as to when momentum is and is not conserved when you collide two gliders. You will have available gliders with different masses and different things you can mount on the end of gliders to interact (including springs, Velcro, magnets). Please identify at least a four different scenarios you could test that span a range of different conditions, including at least one in which you expect total momentum to be conserved and at least one in which you DO NOT expect total momentum to be conserved

2# in the upcoming lab, it will be useful to program Lab Assistant to make graphs of the momentum of each glider and the entire system. In the space below, please make a list of the

·         sensors you will need to set up,

·         derived waveforms and constants you will need to define, and

·         the formulas you will need to enter (including the actual equations)

3#Look over the example lab reports, particularly the abstract. What is the purpose of an abstract? What information is included in it? What information is not included in it? How does it differ from the introduction section?

Answer 1

1# What is the conservation of momentum? Under what conditions is it true?

The "law of conservation of momentum" states that the momentum will remain constant no matter what until and unless any external force comes into action.

For two objects with an initial masses of m₁ and m₂ and initial velocity of v_1i and v_2i with final velocities after collision to be v₁ and v₂, then we have

m₁ v_1i + m₂ v_2i = m₁ v₁ + m₂ v₂

The conservation laws are applicable for an "isolated system".

The momentum of an isolated system is a constant. The vector sum of the momenta (mv) of all objects of a system cannot be changed by interactions within the system. This puts a strong constraint on the types of motion which can occur in an isolated system. If one part of the system is given a momentum in given direction, then some other parts of the system must simultaneously be given exactly the same momentum in an opposite direction. We can say that, conservation of momentum is an absolute symmetry of nature.