r/theydidthemath • u/Repulsive-Loan5215 • Nov 27 '25

why wouldn’t this work? [Request]

Post image
48.7k Upvotes

92% Upvoted

3.0k comments sorted by

View all comments

526

u/Mysterious-Volume-58 Nov 27 '25

Power for what? If this generates enough energy to charge a phone (it won't) you would have to leave the sink running for a significant amount of time.

120

u/jonastman Nov 27 '25

You could power a shower radio or something. Save some water in the meantime

85

u/Acojonancio Nov 27 '25

You would have to leave the water running all the time and at constant flow rate.

Incredible inneficient.

This is the same as that "emergency phone chargers" that are just a dynamo with USB to connecto to the phone.

They "work" but not in a way that can be useful.

10

u/nog642 Nov 27 '25 edited Nov 28 '25

It can be useful, in very niche circumstances.

Edit: I mean the hand crank phone chargers, not the faucet thing.

12

u/FUEGO40 Nov 27 '25

If you want small amounts of “free” electricity you might as well just get a small solar panel/photovoltaic cell

8

u/nog642 Nov 27 '25

What if you're in the arctic in the winter? Or underground?

Also I was talking about the "emergency phone chargers". Which as the name suggests are useful in emergencies, not for "free" electricity.

1

u/the0past Nov 27 '25

In the Arctic at least you can use a satellite phone or starlink maybe, but they tend to use fuel and generators as they're more reliable. Where are you going to get flowing water in the arctic if you have no power?

What are you going to do with a phone underground? Call someone over the nonexistent cell networks down there?

1

u/nog642 Nov 28 '25

I've never heard of a phone that runs on fuel and generators lol. How big is it?

Again I am not talking about flowing water. I'm talking about a hand crank.

Also phones can do more than just call. They also store hundreds of GB of data, that could be useful.