How much heat is lost in an hour through a glass window measuring 2.0 m by 2.5 m when inside temperature is 25⁰C and that of outside is 5⁰C, ,the thickness of glass is 0.8 cm and the value of k for glass is 0.8 Wm⁻¹K⁻¹? (3.6 x 10⁷ J)