Twothreeten

Thanks, I'll look into those ideas.

I recently had to do an experiment to show how aluminium absorbs β-particles from a strontium source. I was wondering, does the distance between the source and the aluminium sheet affect the absorption if the Geiger tube is the same distance from the strontium?

I don't think that's correct because a falling object will continue to accelerate under gravity until it reaches its maximum velocity or it collides with something - like the Earth's surface - between it and the centre of gravity. It doesn't decelerate when it hits the ground; the reaction force of the ground stops it falling any further. The reaction on the object opposes gravity which stays constant throughout the fall and when it's on the ground (unless it's fallen a very long way).