A catapult launches a pumpkin from the base of a hill. The hill follows an incline with the height in meters, y, in terms of horizontal distance in meters, x, given by the equation y=0.9x. The height of the pumpkin, as it is launched uphill, is given by the function f(x)= -0.1x^2+4.9x.
What is the height, in meters, where the pumpkin lands on the hill?