Independent, dependent,and control variables for science project?

im doin a friction project for science and i need to know the independent and dependent variables and what i should keep constant (constant variables). i said that the friction created is the ind. variable and that the surface that the friction was created on is the dep. variable, but im not sure.Independent, dependent,and control variables for science project?
backwards.





you are trying to measure the friction for different surfaces (perhaps by sliding something over an inclined plane covered with that surface and measuring the time?)





if so, the surface is the independent variable and the total sliding time


(which you can then convert to the coefficient of friction) is the dependent variable..





the control variables are the angle and length of the inclined plane etc...





do i understand the question correctly? cheers





EDIT: re: your followup clarifications ';yes but its not on a plane. its on a desk with a type of material under it. there is a block with taped paper clip on it and string with a cup attached to the end of it. at the end of the material is a tube that stops the block from falling down.';





o.k. - you're not using an inclined plane, but the experiment, and how you will be interpreting the data you collect, is essentially the same in terms of the effect of friction. so my comments still work in terms of your posted question...





cheers