During male orgasm, the smooth muscle of the penis must contract with sufficient force to ejaculate semen from the penis.

Is the mean velocity of ejaculation known? I do not find scientific sources. I only found 17 km/h in the media without further elaboration.

Moreover, in some species, males must compete with other males for egg fertilisation. Presumably, evolutionary forces would favour those who had a greater ejaculation velocity. Is there a relationship between the velocity of male ejaculation and fertility?

  • 3
    I'm voting to close this question as off-topic until it can be explained how this is anything over than trivia.
    – JohnP
    Commented Jun 28, 2018 at 17:31
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    Why? What is wrong with this? There are two velocities documented online, but I do not find the scientific source. I write about pelvic muscles and urologIcsl issues, so how can you judge whether it is trivial or not. Maybe to you, not for me.
    – Doc17
    Commented Jun 29, 2018 at 6:14
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    I am just speculating but due to the inhospitable nature of the vagina to the sperm, maybe ejaculation velocity will help increase fertilisation rates if the velocity is higher than average due to muscle tones @Doc17 mentioned. However, motivation for the question does need to be provided so I would suggest, Doc17, that you need to put some of your findings into your question and provide reasons for why you would like to know such things. Is it something like I mentioned? Commented Jun 29, 2018 at 8:20
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    There is nothing in your question about muscles or urology, other than they have to be there. As Chris says, reasoning behind why you would like to know, and the relation to health could make it on topic (as I referenced in m close comment). The media sources you reference would also help.
    – JohnP
    Commented Jun 29, 2018 at 14:02
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    i found the answer. i've also suggested an edit to make it appropriate.
    – faustus
    Commented Jun 29, 2018 at 20:32


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