When you have studied the 4.3 Further Mechanics 73-75 handout given out in class, try this…
This is a simulation of a linear air track, which you might have seen briefly before in the IG course. The trollies or carts float on a cushion of air, so can move horizontally with a gentle push at more or less constant speed. If the carts have small magnets attached to them, they can either stick together and collide inelastically or repel each other without touching, simulating elastic interactions. You can vary the speeds along a straight line, also the masses of the carts, hence calculate momenta and kinetic energies.
Also read 4.3 Further Mechanics 76
For a momentum calculator, click on this link. There’s lots that Wolfram Alpha can help you with. It’s worth having a look around, especially at the Maths parts.