4. This question relates to the solution of a simple first-order differential equation using Euler's method. It forms the basis of the terminal velocity problem. a) The equation of motion of a mass undergoing free fall in air is given by the following equation. mdtdv=mgcv Briefly explain the meaning of each term and using the relationship below transform the equation above into a simple recursive relationship between vn+1 and vn using Euler's method. dtdvtvn+1vn [15 marks] b) If vo=0.0,g=10,m=1 and c=2 use the Euler's method to find v1,2,3,4 if t=0.1 and so plot the velocity as a function of time. [10 marks] c) Considering the original equation of motion given in part a of this question, what will the terminal velocity be