How long will it take a runner to go from 1.8 m/s to 3.2 m/s if they can accelerate at 0.25 m/s^2? First which formula will I use and how will I solve this problem?

2. How long will it take a runner to go from 1.8m/s to 3.2m/'s if they can accelerate at 0.25m/s