|The Physics of Pull-Ups - sunday 2005-04-17 0648||last modified 2005-04-18 1449|
|Categories: Nerdy, Daily Grind|
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I thought of installing a chin-up bar in my room. The immediate question of where to put it pointed directly at a relatively narrow alcove in the back. However, one wall is the kind of false, hollowed wall covering you find in an average suburban home, the kind that necessitates a stud detector to find appropriately sturdy mounting points. The opposing wall is solid brick. So I got to thinking about the mechanics of a bar around a spring that exerted force towards the walls instead of requiring drilling or pounding nails.
It would need to have enough frictional force on the ends to oppose the force of the weight of the bar itself and me along with any other sudden applications of force. Except the surfaces of the opposing walls are uneven and it's likely the smooth, false wall would provide more surface area for friction, whereas the uneven brick wall would provide too many breaks for an equal frictional force on both ends of the bar. Which means there might be a substantial net torque exerted on the bar if I'm not pulling up on the correct part of the bar, which means it and I would fall.
So, anybody know anything about drilling in brick? I guess if one end is mounted well in the brick side, the other end won't need to be fixed in place.