IGCSE Physics Thermal Physics Long Question Answers

“A student is tasked with designing a system to keep a small room at a constant temperature. The room loses heat to the surroundings at a rate of 500 J/s. The student has a heater that can provide heat at a rate of 800 J/s. Describe the steps the student should take to ensure the room remains at a constant temperature, explaining the concepts of heat transfer involved and how they apply to maintaining a stable thermal equilibrium. A container holds 2.0 kg of water at 25°C. A 500 W heater is immersed in the water. Assuming no heat is lost to the surroundings, calculate how long it will take for the water to reach 100°C. Then, describe what happens to the energy supplied by the heater after the water reaches 100°C, explaining the concept of latent heat and its role in the phase change of water. (Specific heat capacity of water = 4200 J/kg°C)”