Science Buddies: "Ask an Expert"

OK, so i'm conducting an experiment where you are finding if the height a marble is dropped at on a ramp affecrts its stopping distance, and i plan to write a method, evaluation etc. to go with it. BUT first i need to answer a few questions. So it said: Whats the independet variable? I answered saying the height of the marble, it then asked for the dependent variable. i answered with the height of the ball, mass of the marble.....

BUT then it asked for the KEY variables. Could some one explain this? define KEY variables!
i'm confused

Hi,

You should take a look at Science Buddies' guide to variables, here: https://www.sciencebuddies.org/science- ... bles.shtml; I think you will answer the question about dependent variables differently after having read it. However, it does not talk about 'key' variables--this seems like it is something specific to your science fair, and I would ask your teacher what he/she means if I were you. My guess is that since 'key' normally means 'important', he/she means your most important independent and dependent variables--for example, height of the marble. But I would double-check with your teacher to make sure.

Dear habbity,

I have found that "key variable" is another term for "dependent variable," so I'm not sure what your prompt could have been referring to. It might have something to do with the fact that you typed in "height of the marble/ball" for both independent and dependent variables. It sounds like height of the marble is the dependent variable and that other factors such as the length of the ramp (and where you drop it onto the ramp) and the mass of the marble are independent variables, unless you are testing other factors such as how far the marble travels depending on the mass of the object. You might want to clarify with your teacher which variables you are testing.

Hope this helps!

Michelle