An electric heater supplies heat to a system at a rate of `100W`.If system performs work at a rate of `75` joule per second ,at what rate is the internal energy increasing?

DeltaU=q-pDeltaV. If the process is carried out at constant volume, then DeltaV=0. Answer the following questions. a) Give the equation for DeltaU. b) 1000J was supplied to a system at constant volume. It resulted in the increase of temperature of the system from 45^oC to 50^oC. Calculate the change in internal energy.

An electric heater working at 230 V produces 1000 J energy in one second. What is the power of the lamp ?