Question

Hypothesis: If I put a chocolate bar on the table near a sunny window, it will melt faster. If your independent variable is the placement of the chocolate bar and the dependent variable is the speed at which it melts, what are some controlled variables that one must have during each trial?

Answer 1

The temperature of the room which way the sun is shining from

Answer 2

Type of chocolate bar, size of it, surface it is placed on, etc

Controlled variables are anything that stay the same for both trials