A very long copper rod of $3cm$ diameter of thermal conductivity $386\frac{W}{m}K$ has one of its end maintained at a constant temperature by holding it a furnace while the remaining portion of rod exposed to an ambient at $25C$ at steady state, the temperature at two location that are $25cm$ apart along the length of rod are measured to be respectively $200C$ and $100C.$ Calculate convection heat transfer coefficient offered by the environment.