Position sensor for moving projectile

[Jdo300]

Hello All,

I am going to be conducting a basic physics experiment where a magnet, which can slide up and down a vertical pole is launched upward using an electromagnet. I am not sure how high this magnet will go yet but I'm expecting a maximum vertical displacement of no more than 6-12 inches. My question for you all is how to most accurately measure the maximum vertical displacement of the magnet when it is propelled upward?

Ideally, I want to use some kind of sensor to measure and record the maximum displacement that the magnet is launched to but I'm not sure how to accomplish this in an accurate way. I was thinking about using a series of proximity switches that could be triggered as the magnet is moving past but at this point, the displacement could be as little as 1/2 inch which would make it very hard to accurately calculate the vertical velocity and deceleration to get the height. What do you all think?

Thanks,
Jason O

 

[kuruman]

Presumably this is not a random launch and there is an independent variable associated with the electromagnet that controls the maximum height. A low tech solution to the problem is to watch a couple of launches and then clamp a stop on the pole at the point wheree you think the max. height is. Repeat the experiment and adjust the stop until the electromagnet barely reaches it. Listen for the sound of the electromagnet hitting the stop. You have maximum height at the point where the sound of the collision disappears.

I agree with you, having fixed sensors is problematic.