For his science fair experiment, Cole decided to determine how different types, of surface material , affect how fast a matchbox car will go. He chose to use a tile floor, concrete patio and carpet.He used the same car for each of the 20 trails. He measured the distances the car went after riding down a 1 meter-ramp.
What is Cole's test ( independent) variable?
What is Cole's outcome ( dependent) variable) ?
What must be kept constant ( the same) for every trail?
What do you predict will happen and explain why.