The Total solution for NCERT class 6-12
According to law of conservation of energy
Total energy = work done + internal energy
ΔQ = ΔW + ΔU
Here,
Rate at which heat is supplied ΔQ = 100 W
Rate at which work is done ΔW = 75 Js-1
Rate of change of internal energy is ΔU
ΔU = ΔQ – ΔW
ΔU = 100 – 75
We get,
ΔU = 25 J s-1
Hence,
The internal energy of the system is increasing at a rate of 25W