Do you get the same result if the conical flask is not closed?

To demonstrate, "black surface absorbs more heat as compared to a white surface". Apparatus - Materials : Conical flasks, water, thermometer Procedure : rarr Take two conical flasks and paint one white and the other black. rarr Fill water in the both flask. rarr Place the conical flasks in direct sunlight for half an hour to one hour. rarr Measure the temperature of the water in both conical flask with a thermometer. If you touch the conical flasks, which one is hotter ?

To demonstrate, "black surface absorbs more heat as compared to a white surface". Apparatus - Materials : Conical flasks, water, thermometer Procedure : rarr Take two conical flasks and paint one white and the other black. rarr Fill water in the both flask. rarr Place the conical flasks in direct sunlight for half an hour to one hour. rarr Measure the temperature of the water in both conical flask with a thermometer. Which property is used in solar cooker and solar water heater ?

To demonstrate, "black surface absorbs more heat as compared to a white surface". Apparatus - Materials : Conical flasks, water, thermometer Procedure : rarr Take two conical flasks and paint one white and the other black. rarr Fill water in the both flask. rarr Place the conical flasks in direct sunlight for half an hour to one hour. rarr Measure the temperature of the water in both conical flask with a thermometer. In which ways this finding can be used in our daily life ?