Lego Shake Table - Is it possible to have two Independent Variables?

[jg9]

Hi - I am working on a project which mimics earthquakes - Building the Tallest Tower. I need to list out my Independent Variable for my project but am becoming very confused. It is what I change. So I am changing the height of the buildings I build to see if it affects their stability (Dependent Variable). Yet, I am also changing the amount of shake (displacement) to see how that affects the buildings I build. Can an experiment have two independent variables? Any help would be great!

[MadelineB]

Hello and welcome to Science Buddies,
This sounds like a fun and important project.
The Science Buddies project guide has a helpful section on Constructing a Hypothesis with subsections on variables.
https://www.sciencebuddies.org/science- ... ience-fair

Read through those sections and see if that helps! Please be sure to let us know if you have more questions.

[cumulonimbus]

Hi jg9,

In general, you should only test one independent variable at a time. I would suggest picking just one variable; either change the height of the buildings with the same displacement for each one or change the displacement but keep the height constant. If you want to test both variables, you could conduct two separate experiments, or you could test each building height for several different displacements and compare each building height with the same displacement as well as compare the different displacements for one specific building height. Don't compare two buildings with different heights and different displacements, though. I hope this helps and good luck on the project!

Sincerely,
Elena