At what angle does the coefficient of lift over a flat plate become maximum?

A)
33.3 deg
B)
54.7 deg
C)
66.6 deg
D)
90 deg

Correct Answer :   54.7 deg


Explanation : According to the Newton’s theory, the coefficient of lift is given by :

cl = 2sin3α

This value is maximum for α = 54.7 degrees.