Question

A solar heating system has a 25.0% conversion efficiency; the solar radiation incident on the panels is 1 000 W/m2.

What is the increase in temperature of 30.0 kg of water in a 1.00-hperiod by a 4.00-m2-area collector? (cw = 4 186 J/kg⋅°C)a. 14.3°Cb. 22.4°Cc. 28.7°Cd. 44.3°C

Answer 1

Rise in temperature will be
`28.7^(\circ)C`

So option (c) will be the correct answer

Step-by-step explanation:

We have given solar radiation on the panels
`=1000w/m^2`

25 % of the conversion efficiency = 25 % 1000 = 250

Area is given
`A=4m^2`

So radiated power
`P=250* 4=1000watt`

Time is given t = 1 hour = 3600 sec

So energy
`E=power* time=1000* 3600=3.6* 10^6J-sec`

Mass of water m = 30 kg

And
`c_w=4.186`

So rise in temperature
`\Delta T=(Energy)/(m* c_w)=(3.6* 10^6)/(30* 4.186)=28.7^(\circ)C`

So option (c) will be the correct option