A ball is projected vertically upwards from a point 4 m above horizontal ground with speed 8 m s-1. The ball is modelled as a particle moving freely under gravity. Use g=9.8 m s−2g=9.8\text{ m s}^{-2}g=9.8 m s−2.
Find the time taken for the ball to reach the ground. Give your answer to 3 significant figures.