Respuesta :

We know, a = Δv / t
Here, a = 1.4 m/s²
Δv = 26-20 = 6 m/s

Substitute their values, 
1.4 = 6/t
t = 6/1.4
t = 4.28 s

In short, Your Answer would be 4.28 seconds

Hope this helps!