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€“] 15 points 1 month ago

The effect of gravity is the same as movement. We are all "falling" towards the center of the Earth, at all times. You holding onto something heavy, is preventing it from falling...so the force needed to keep it stationary is equal to the force of gravity pulling it down.

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