Answer in Physics for Mike #226543
Here’s what I believe the complete condition of the problem is:
An electric immersion heater has a power rating of 1500 W. If the heater is placed in a liter of water at 20°C, how many minutes will it take to bring the water to a boil? (Assume that there is no heat loss except to the water itself.)
So, the energy required to increase the temperature is
The electrical energy required for this is equivalent to power times time:
or 3 min 44 s.