4Forces, Friction, and Torque (Oh My!)

Have you ever tried to push open a door, only to realize you’re pushing on the wrong side—the one closer to the hinge—and it’s really hard to open? This happens because a door needs a certain amount of torque to open, and if you push too close to the hinge, you have to use a lot more force than if you push at the handle to create the same amount of torque. I suggest pushing on doors in the middle to avoid embarrassment.

In order to estimate torque, know where on the door to push, figure out if something will break, choose a motor, or pick a material for a project, it helps to think about the world around us in terms of numbers. So, before we get to examples of forces, friction, and torque, we need to review ...

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