Answer

a) Use v² = u² + 2 as (1) u² = -2 x - 10 m s^-2 x 3.5 m = 70 m²s^-2 (1) u = 8.4 m s ^-1 (1)

b) Time travelling upwards, t= distance / average speed = 3.5m / 4.2 m s ^-1 = 0.83 s (1) Time in air = 1.66 s (1)