1. The problem statement, all variables and given/known data The mechanical equivalent of heat is 1cal=4.18J. The specific heat of water is 1cal/g*K and its mass is 1g/cm^3. an electric immersion water heater rated at 400 W should heat a liter of water from 10C to 30C in about how much time 2. Relevant equations R=v/i power=v*i 3. The attempt at a solution I know the answer is 3.5 minutes but i do not know how to get there. Im pretty lost.