Same temperature: kinetic energy is the same ( irrespective of whether solid or liquid or gas)
Internal energy is sum of ke and pe of all the molecules.
Potential energy of gas higher than water as the molecules are further apart. If the gas molecules very far apart (taken to be zero) than in water the PE is negative. Similar to gravitation where infinity is taken to be zero below that at r distance is negative.
Thus internal energy of gas is higher than internal energy of water since PE is the factor taken into consideration as KE is the same.
Check this out at Pg 111 of TYS 2007. N98P3Q5
b) The principle is heat loss equal to heat gained .
Power gained from the sun= I A
Power loss due to vaporisation = mL, where m is rate of mass vaporising. To find volume vaporising v = m /density. The answer is 0.187 m3s-1.
If water is disappearing at a rate of 0.187 and rate needed is 2.7 , you need to supply 2.89 m3s-1.
iii) reduce area of exposure using pipe - cost
reduce temperature of water to reduce vaporisation
