Need help with part c of the question, I have attached my Mathcad file where I have tried to solve for radius with an effectiveness factor of 0.97. Please Help!
You can't use a function derived by the numerical odesolve for symbolic calculations like "solve".
You rather should use either a (numerical) solve block with "find" or the "root" function.
BTW, in the equation you'd like to solve for RR, shouldn't it be W(RR) instead of W(R)?