A composite string is made by joining two strings of different masses per unit length μ and 4μ. The composite string is under the same tension. A transverse wave pulse. y=(6 mm)sin(5t+40x), where 't' is in seconds and 'x' is in meters, is sent along the lighter string towards the joint. The joint is at x=0. The equation of the wave pulse reflected from the joint is y=(2 mm)sin(5t−40x+π). The percentage of the power transmitted to the heavier string through the joint is approximately