An immersion heater used to boil water for a single cup of tea plugs into a 120 V outlet and is rated at 300 W.
A) What is the Resistance of the Heater?
B) Suppose your super-size, super-insulated tea mug contains 400 g of water at a temperature of 16 degrees C. How long will this heater take to bring the water to a boil? You can ignore the energy needed to raise the temperature of the mug and the heater itself.