Two travelling waves of equal amplitudes and equal frequencies move in opposite directions along a string. They interfere to produce a stationary wave whose equation is given by \( y=(10 \cos \pi x \sin \frac{2 \pi t}{T}) \, \text{cm} \). The amplitude of the particle at \( x=\frac{4}{3} \, \text{cm} \) will be _______ \( \text{cm} \).
