Geometrical Optics

A pole is vertically submerged in swimming pool, such that it gives a length of shadow \(2.15 \mathrm{~m}\) within water when sunlight is incident at angle of \(30^{\circ}\) with the surface of water. If swimming pool is filled to a height of \(1.5 \mathrm{~m}\), then the height of the pole above the water surface in centimeters is \(\left(n_{w}=4 / 3\right)\) ____________.