Answer:
Energy change = 59. 5 kJ
Explanation:
First, we collect the data:
Let:
Q (supplied) be the energy supplied to the water
Q (lost) be energy lost to surroundings
Q (piston) be the energy possessed by the piston as it moves up
v = volume flow (m³/s)]
V = velocity of the gas (m/s)
mass = 50 kg
Second, calculate the work done by the piston:
to find velocity, we use this formula:
v = A × V
Therefore, V = 0.5 (m³/s)/0.005 m²
= 10 m/s
it means the water is evaporating at a rate of 10 m/s
the evaporating water transfers energy to the piston, kinetic energy Ek
Ek = 1/2 mV²
= 0.5 (50) ( 10) ²
= 2 500 J
= 2.5 kJ
The net energy, ΔQ is given by:
ΔQ (net) = Q (supplied) - Q (piston) - Q (lost)
= 70 - 2.5 -8
=<u> 59.5 kJ Ans</u>
