Question 1: Define the term 'thermal energy store' in the context of physics.

Answer: A thermal energy store is the energy stored within a body due to the random motion of its particles.

Question 2: Describe briefly how heat is transferred through conduction in a solid.

Answer: Heat is transferred through conduction by particles vibrating and passing energy to neighbouring particles without overall movement of the material.

Question 1: Calculate the thermal energy transferred when 500 g of water is heated from 20°C to 80°C. Use the specific heat capacity of water as 4200 J/kg°C. Show your working.

Answer: Q = mcΔT = 0.5 kg × 4200 J/kg°C × (80°C - 20°C) = 0.5 × 4200 × 60 = 126,000 J

Question 1: Outline a simple experiment to investigate the effect of insulation on heat loss from a container of hot water. Mention variables to control and safety precautions.

Answer: An experiment involves wrapping a container of hot water with different insulating materials and measuring temperature changes over time. Control variables include initial water temperature, container size, and amount of water. Safety precautions include careful handling of hot water and using heat-resistant gloves.

Question 1: A metal block of mass 2 kg is heated to 150°C and then allowed to cool. After 10 minutes, its temperature drops to 100°C. Explain what factors could affect the rate of cooling and how the thermal energy store of the block changes during this process.

Answer: Factors include thermal conductivity of the surroundings, surface area, and temperature difference. The thermal energy store decreases as the block loses heat to the environment.

Question 1: Explain how thermal insulation in buildings helps to save energy and reduces heating costs.

Answer: Thermal insulation reduces heat transfer from inside to outside, maintaining warmer indoor temperatures and reducing the energy required for heating.