An Electric Kettle is used to boil water. After the water is boiled, the temperature of the water decreases by 22C. The mass of water in the kettle is 0.50 kg. The specific heat capacity of water is 4200 J/kg C. Calculate the energy transferred.

First, we need to recognise which equation to use. From the Physics Equation Sheet, we can see that the correct equation here is that dQ=mcdT, where dQ is the Energy transfer. Using this equation, we can see that dQ = 0.50 * 4200 * -22 = -46200 J. We can check that all of our units match up too. If the water loses 46200 J, then the surroundings must gain 46200 J.