How fast does pee come out? A gap in scientific knowledge

[Kupar 13,212]

From yesterday's Guardian newspaper kids quiz.

 

[wivace6455 21]

Looks like we need to do some research! If someone designs an experiment I'm sure a lot of us would be happy to participate!

[wettingman 530]

I would think it can vary significantly. It would depend on the size of a person's urethra and the actual pee hole, determining how fast it can cone out.

Also how badly the person needs to pee. If their bladder is full the pee would be pushed out harder. If they are too full and the bladder is seriously stretched, it may not be able to push as hard. You need to be in that sweet spot.

On one If my more memorable pees I must have hit that. I had to go pretty badly . When I let go I experienced a unusual sensation. I could feel my pee hole stretch as my pee gushed out at high velocity and pressure. Not at the time but I later recorded my urethra opening , it does not open very far .

It has been shown that females pee faster than males because of their short ,straight down urethra.

A study of the matter could be interesting but I don't know how you can calculate the actual speed of urine flow.

I do member some board college students measuring the speed of ketchup flowing from the bottle..   So maybe.... Who wants to volunteer to be a test subject.

 

 

 

 

[Pinguy94 91]

58 minutes ago, wettingman said:

I would think it can vary significantly. It would depend on the size of a person's urethra and the actual pee hole, determining how fast it can cone out.

Also how badly the person needs to pee. If their bladder is full the pee would be pushed out harder. If they are too full and the bladder is seriously stretched, it may not be able to push as hard. You need to be in that sweet spot.

On one If my more memorable pees I must have hit that. I had to go pretty badly . When I let go I experienced a unusual sensation. I could feel my pee hole stretch as my pee gushed out at high velocity and pressure. Not at the time but I later recorded my urethra opening , it does not open very far .

It has been shown that females pee faster than males because of their short ,straight down urethra.

A study of the matter could be interesting but I don't know how you can calculate the actual speed of urine flow.

I do member some board college students measuring the speed of ketchup flowing from the bottle..   So maybe.... Who wants to volunteer to be a test subject.

 

 

 

 

I have had similar where my urethra felt really stretched and a few of those times I had to go horribly bad, and I have recorded mine during a desperate pee and it can open fairly wide when needed 

[wivace6455 21]

Someone should check my math, but I think if you divide the flow rate in ml/second by the area of the urethra, that should be the speed of the flow right? If my math is right there then from some quick googling of averages I think a typical flow is more like 1.2 km per hour

[Kupar 13,212]

3 hours ago, wivace6455 said:

Someone should check my math, but I think if you divide the flow rate in ml/second by the area of the urethra, that should be the speed of the flow right? If my math is right there then from some quick googling of averages I think a typical flow is more like 1.2 km per hour

I don't know what averages you're using, but certainly volume flow rate divided by urethra cross sectional area would give you a velocity and that's probably the most straightforward way for averages. I don't fancy trying to measure my own urethra cross sectional area, and while you could try to measure the pee stream area with a close up photo I reckon the error in measurement would be big.

You could make a high speed video when the pee begins, with the subject standing or squatting close to a piece of paper with a scale marked on it. Or use a radar speed gun. Apparently there used to be one made by Mattel designed for use with Hotwheels toy cars https://www.eetimes.com/mattel-makes-a-real-radar-gun-on-the-cheap/