premise: friction occurs when two object 's surfaces move against each other sent2: a tire is a kind of object sent3: if the tire overheats, some chemical in the tire will vaporized sent4: skidding is when the tire of a vehicle slides on the road without rotating sent5: a surface is a part of an object sent6: a chemical is a kind of substance sent7: if the temperature of the tire keeps increasing, the tire will overheat sent8: if somethings slides on something else then that something is moving against that something else sent9: friction causes the temperature of an object to increase.
hypothesis: friction causes the tire to produce smoke