The reason it’s a tenth off is because you are still accelerating until about 65m.
Everyone needs to remember that each plate (10 meters), of your race will almost always have a different time. The less time you’re dealing with (40yards/55m/60m/), it’s espescially much more difficult to make a guessimate of (based on other distances), because the 0-60m distance is much more calculitably unstable mostly due to acceleration phase.
You’re calculating your average m/p/s. You have to view it in chunks.
Run next to your buddy’s car or bike/wspeedometer to find out your top mph, convert that down to m/p/s and you have your top speed.
Based on things I’ve read and heard, a solid sprinter reaches top speed at about 45-60 and can maintain it for a plate of time of about 10-15m.
Your top speed is much faster than 8.anything, and at least over ten m/p/s quik. (which I’m sure you know)
Take your top speed and divide into those last or extra 5 meters, tack this onto your 55 time, and you got it.
use these calculators to make things easier – https://www.onlineconversion.com/length_common.htm – to convert lengths
https://www.onlineconversion.com/speed_common.htm – to convert your speed