125 water droplets, each of radius r, coalesce to form a single drop. The energy released raises the temperature of the drop. If $\mathrm{\sigma }$ represents surface tension, $\mathrm{\rho }$ represents density, S represents specific heat, then the raise in temperature of the drop is $\frac{(\mathrm{\eta }+7)\mathrm{\sigma }}{\mathrm{\eta r\rho S}}$ where $\mathrm{\eta }$ is a dimensionless constant. Find $\mathrm{\eta }$.