Question about Marble Roller Coaster Experiment

[Rebekahlovsanimals]

Hi!

My son is doing the Marble Roller Coaster Experiment (https://www.sciencebuddies.org/science- ... p-the-loop).

The instructions for the project state:

12) Run a single marble down the track 10 separate times. How many times does it successfully go through the loop?
13) Change the height and repeat the previous step. If the marble makes it through the loop most of the time, lower the height. If the marble fails to make it through the loop most of the time, raise the height.

I'm not sure how to raise or lower the height without moving where the marble run is attached to the floor as well. If my son needs to change the height, how can he do so without adding another variable? Is it okay to move the loop that's taped to the floor closer or further to make it possible to raise or lower the height?

Thank you!

[bfinio]

Hi - you don't need to change the height of the actual track to do this, you can just change the starting location of the marble on the hill. It doesn't always have to start at the very top. Hope that helps!

[Rebekahlovsanimals]

Okay, thank you so much!