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If energy is movement, how come I get tired just from holding a heavy object? (multiverse.soulism.net)
submitted 1 month ago by to c/nostupidquestions@lemmy.ca
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In high school physics, I learned that the equation for energy from moving something is a factor of force and displacement. So if an object remains stationary, then no matter how much force is put into it, no energy is expended.

So how come if I hold a heavy box filled with dumbbells, I get tired? I'm obviously putting a lot of newtons into it to keep it from falling, but it's not moving. So how is the weight of the object causing Me to expend energy?

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[โ€“] 11 points 1 month ago (1 child)

You're opposing the pull of gravity. It's not moving because of the effort you put in to keep it that way.

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  • [โ€“] 5 points 1 month ago

    Depends on perspective. You could also argue that it IS moving, and your effort is part of what keeps it moving in the same path instead of deviating towards the center of the earth, which would involve less energy. Like riding a bicycle around a velodrome; the energy of pushing forward keeps it from falling into the center.

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