I think you want to determine the exit speed?
You have to determine how much velocity was decreased by calculating it from the kinetic energy.




So the velocity reduces by 15.95 m/s. Subtracting this to the initial velocity: 22 - 15.95 = 6.05 m/s.
So, the final speed was 6.05 m/s.
I hope I was able to help :)