Question

surfaces distance marble traveled carpet 30 cm smooth tile 150 cm cement sidewalk 60 cm plastic 95 cm a student rolled a ball across different surfaces to see how far the ball would roll. the scientist changed the ____________ to see how far the ball would roll each time. the different surfaces are the ____________. a. independent variable b. dependent variable

Explanation:

In an experiment, the independent variable is what is changed. Here, the student changed the surfaces (carpet, smooth tile, etc.). The dependent variable is what is measured (distance the marble traveled). Since the surfaces are being changed to observe the effect on the distance, they are the independent variable.

Answer:

a. Independent variable