How might we determine if one thing causes another?​

Answer8.0m;

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

Answerit is comparative because this experiment is comparing the results of the volume at minimal pressure and then increases it; ; ;