In an experiment to investigate transpiration, a student prepared a leaf where the upper surface was sealed with waterproof grease, leaving only the lower surface exposed.
The exposed lower surface of the leaf has an area of 25 cm2. Over a period of 4 hours4\text{ hours}4 hours, the leaf lost 0.45 g of water.
Calculate the rate of water loss from the uncovered surface of this leaf in g cm−2 hour−1\text{g }\text{cm}^{-2}\text{ hour}^{-1}g cm−2 hour−1.