1. consider an infinitesimally thin airfoil that has a shape like a parabola: the free stream is parallel to the x- axis. note that the slope of the airfoil is zero at the leading edge (x=0) so that the free stream is parallel to this airfoil leading edge. assume that the freestream mach number is 2.059, and zmax/c=0.1.a) find the expressions for the lift coefficient, drag coefficient, lift to drag ratio, and the moment coefficient about the leading edge using ackert's rule. ans. c1-0., cd=0.0296, collef-0.1482 b) sketch cp vs x/c for the upper and lower surfaces (on the same graph). use ackert's rule. note: if you had done this problem using shock-expansion theory covered in ae 2010, you will get cl- 0.2286, cd- 0.0302, and l/d 7.57.