When a football is kicked, its height can be modelled by the function h(d)=−0.1d2+4.8d, where d is the horizontal distance that the ball has travelled, in metres, and h is the height of the ball, in metres.

a) Write a quadratic equation that can be used to determine the distance that the ball has been kicked. What is the height of the ball when it lands on the ground?
b) Solve the quadratic equation to determine the distance the ball travels.