So, the axial component will be equal to the speed of the ship that is, if I draw it just here, if the ship speed is v and this will be v, the axial component of the wave whereas, the actual ship, actually this velocity will be v cos theta where this is theta, the enclosure, the envelope angle, this is theta, this is theta. So, then, the length of the divergent waves will be into cos square theta where this is theta, this angle is theta that is, this angle now, making mistake this is, this is not the, this thing, this is the velocity v cos theta, this is the theta angle, this is the velocity of the divergent waves in its own direction whereas, axial direction the velocity will be equal to ship velocity.