With this information, you can calculate the quantity of feet per second 9 knots is equal to.

¿What is the inverse calculation between 1 foot per second and 9 knots?

Performing the inverse calculation of the relationship between units, we obtain that 1 foot per second is 0.065831533 times 9 knots.

Which is the same to say that 9 knots is 15.190289 feet per second.

Nine knots equals to fifteen feet per second. *Approximation

A foot per second is zero times nine knots. *Approximation