A liquid of density \( 750\,\text{kg m}^{-3} \) flows smoothly through a horizontal pipe that tapers in cross-sectional area from \( A_1 = 1.2 \times 10^{-2}\,\text{m}^2 \) to \( A_2 = \frac{A_1}{2} \). The pressure difference between the wide and narrow sections of the pipe is \( 4500\,\text{Pa} \). The rate of flow of liquid is ____________ \( \times 10^{-3}\,\text{m}^3\text{s}^{-1} \).
