E) The heights metres of a mass projected vertically upward at time t seconds is given by: s = ut - 1/2/gt²

Where u is the initial velocity and g is the acceleration due to gravity. (Note: if we take upward motion as positive and gravity acts

downward then we need to replace the acceleration term in D above with -g which accounts for the above form of the SUVAT

equation in this question)

i) Rearrange this equation in terms of the time, t to form a quadratic equation

ii) By solving the above quadratic equation, determine how long the mass will take after being projected to reach a height of 16 m (a)

on the ascent and (b) on the descent, when u = 30 m/s and g = 9.81 m/s²