All I need is a Warm Shower.....

Here, the above diagram shows a common sight of a solar heating system put in place.

On a particular day, you came back home early in the afternoon and felt that you had a really long day at work. All you want to do is to take a warm shower, a light meal and some sleep..... However, a few weeks ago, one of your neighbors commented that your solar panel was not of a high standard and only had a efficiency of $30\%$ %. Due to this, you want to investigate how effective your solar heating system. On this same particular day, the amount of solar radiation falling on the panel is $600W{ m }^{ -2 }$ . Given that the total area of the panel is $16{ m }^{ 2 }$ and at the same time, the water that enters the solar heating system is at a temperature of $15^{ 0 }C$ . Calculate the temperature of the water leaving the shower head when it is operating at the maximum flow rate of $90g{ s }^{ -1 }$ .

Important : Consider the operation of the solar heating system to be working after $5$ hours. To put in simply, use the time duration of $5$ hours to help solve the problem. Don't forget to input your answer in degree Celsius.