Eli5: why are the tips of scissors worse at cutting than the base?
In: 38
In math terms, torque = force * distance. Constant torque divided by big distance means low force. When you grab the scissors and rotate the blades by hand, you apply a certain torque. Now that spreads out over the blade distance to make the tips weak but the base strong.
It’s hard to move a thing strongly when it’s way at the end of a stick — unless you have leverage, which for scissors, you do not have much of. Your leverage happens right at the base, because your handles are close to that base, but your blades are long.
If you compare scissors to a branch pruner, where you have big long handles and tiny but strong blades, you can see the opposite of this happen. Your hands are way out there, so they are applying lots of torque to that hinge. Then, the blades, being very close to the hinge, close with a whole bunch of force and chop off the branch because the distance they have from that point of leverage is so tiny.
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