If I’m hanging onto something, it’s being pulled down by my weight. But if I do a pull-up, does it get pulled down with more force or is it unchanged?

Question

I tried to do think it out but I can’t really wrap my head around the math and where to start.

In: 5

Answer 1

It gets pulled down with more force.

To give a similar but maybe more recognisable example, does jumping up from something push it down?

Also yes, that’s how trampolines work.

If you’re accelerating up due to the force of your legs or arms acting on your centre of mass, an equal but opposite force has to act on whatever your feet/hands are touching.

In vacuum, if you “pulled up” on something, you’d end up pulling it and yourself to your common centre of mass.

If you “jumped off” something, you’d both be accelerated away proportionally to your mass.

Another easy illustration is weighing yourself in an elevator. You’ll see your weight increase when the elevator accelerates up, because you’re exerting more force to stay upright. Otherwise you’d collapse towards the floor of the elevator at the same rate as a stationary reference point outside of it.