A cricket ball thrown into the air is modelled by the following quadratic equation y = 78t - 13t2 , where y shows metres above the ground t seconds after the ball is thrown.\fWhat is highest distance y the ball can reach above the ground?b) The decay of a radioactive substance can be modelled by the equation M = Moe-kt where M grams is the mass of the substance after t years and k is the rate constant. Given Mo = 40 grams and k = 0.3