The projectile is fired vertically; the only force acting on it is the force due to gravity. A force balance yields the equation d2x R2 (R+x)?, dt? Where "x", is the vertical distance measured from the surface of the earth in meters. R is the radius of the earth 6.4 x 106 m. g = 9.81 m/s?. Model this equation using Simulink. Display a graph of the projectile height "x", as a function of time. Assume that the initial height is "0", and the initial velocity is 100m/s. (dx/dt = 100 at time =0).