Question

Julian designs an experiment to see how well different liquids lubricate wooden surfaces. He sets up a number of identical wooden ramps and prepares to slide identical wooden blocks down them. He will time how long it takes each block to reach the end of the ramp. He covers one ramp with water, the second with motor oil, and the third with corn syrup.

What can Julian use as a control group for the experiment?
A.
a block that drops straight down instead of sliding down a ramp
B.
a second set of ramps covered with water, oil, and syrup respectively
C.
a ramp with no friction on its surface
D.
a ramp with no liquid on it

Answer 1

Julian can use **D. a ramp with no liquid on it** as a control group for the experiment. This will allow him to compare how the different liquids affect the movement of the blocks relative to a surface that has no lubrication, providing a baseline for his results.