Group of students is investigating whether the force of friction depends on the nature of the surfaces in contact. The students push two pieces of wood each with the same force on a table. One piece of wood is smooth and the other is rough. The distance traveled by each piece of wood is shown. Experimental Observations
Student 1Student 2Student 3Student 4
Distance traveled by smooth piece of wood20 cm18 cm16 cm19 cm
Distance traveled by rough piece of wood15 cm12 cm10 cm11 cm
What was the outcome variable (dependent variable) in this experiment?

Group of answer choices

Distance traveled

Smooth wood

Rough wood

Number of students