A jet plane lands with a speed of 85 ms and can accelerate

Question

Compute all parts of given question:

Question: A jet plane lands with a speed of 85 m/s and can accelerate at a maximum rate of -4.20 m/s² as it comes to rest.

Part A: From the instant the plane touches the runway, what is the minimum time needed before it can come to rest?

Part B: Can this plane land on a small tropical island airport where the runway is 0.800 km long?

Please show me step by step or type in formulas used. I am so lost!!