With this information, you can calculate the quantity of feet per second 646 miles per hour is equal to.

¿What is the inverse calculation between 1 foot per second and 646 miles per hour?

Performing the inverse calculation of the relationship between units, we obtain that 1 foot per second is 0.0010554461 times 646 miles per hour.

Which is the same to say that 646 miles per hour is 947.46667 feet per second.

Six hundred forty-six miles per hour equals to nine hundred forty-seven feet per second. *Approximation

A foot per second is zero times six hundred forty-six miles per hour. *Approximation