2 A particle \(P\) is projected vertically upwards and reaches its greatest height 0.5 s after the instant of projection. Calculate
- the speed of projection of \(P\),
- the greatest height of \(P\) above the point of projection.
It is given that the point of projection is 0.539 m above the ground.
- Find the speed of \(P\) immediately before it strikes the ground.