Paper Saw Blades- paper cuts paper- Part 1- centrifugal force // Homemade Science with Bruce Yeany
Part one: Can a saw blade made out paper cut through a sheet paper? It can if it's spinning fast enough. Circles of paper are mounted onto a Dremel type tool and then are tested to see if they can cut paper, cardboard foam cups, even thin strips of wood. However, don't look to replace your steel saw blades with these anytime soon, these will disintegrate after a few uses, after all, they are just paper. The demonstration relies on the concept referred to as "centrifugal force". I would point out that this is a fictitious force. The behavior that it describes is real enough, however the words defining it are incorrect. the term "force" used with the word centrifugal is misleading and wrong, there is no force applied radially outwards. However, even though it is mislabeled, the term centrifugal force is used to describe the motion of the matter or an object moving radially outwards. This is what we observe here when the paper straightens out when spinning or the string on a grass trimmer becomes rigid as it spins and can be seen in all sorts of other examples and applications all well. It can be as simple as soaking a towel with water and spinning it over your head. The water drops move away from the towel outwards from the center of rotation ( centrifugal force). We can actually see similar results in the paint trails in the pictures at the endo of my spin art video.
My preference would be to call it a centrifugal behavior. What we are seeing is a cause and effect. The centripetal force which causes the object to curve off of a straight is applied inwards towards the center of rotation. This inward force pulls against the inertia of the object and the effect or result is an outward movement even though there is no outward force.
One further note on safety: I recognize that using the table saw without the guard down is dangerous, it was left up for visual purposes of making the video. My standard procedure is normally to use all safety measures available when using power tools. Also, as has been suggested, I would very strongly recommend that anyone attempting this experiment wear gloves as protection against paper cuts.