An elevator is travelling at 2.00m/s upward when the brakes are put on. The acceleration is a= -1.22m/s^2 while the brakes are acting.

a) How long does it take to bring the elevator to a stop?

b) Calculate the displacement of the elevator while it is being brought to a stop.

a) in this case ... time = velocity / acceleration

... the negative sign on the acceleration is not used in the calculation

b) the average velocity while braking is ... (2.00 + 0.00) / 2
... braking distance is ... average velocity * time