I'm sorry I must go sleep and have free time
I will back to this after one - two week ---

It is too much for one single person !!!

we need only rope / two mass and / light desk ( 0,5 USD )


electric version is impossible to test in home
Many problems !!! very low level of the signal
problems

But classical mechanic -itis more precission than pendulum
almost zero LOST and is very cheap ( everyone can do in home )

On my blog I showed all ( we can eliminate III Newton )

http://marosz-physics.blogspot.com