Question 1: Explain in your own words what thermal insulation is and why it is important in everyday life.

Answer: Thermal insulation reduces heat transfer between objects or environments, helping to maintain temperature and save energy in buildings, clothing, and appliances.

Question 1: What is the main mechanism by which insulation materials reduce heat transfer?

Answer: They trap air or reduce thermal conductivity, decreasing conduction, convection, and radiation of heat.

Question 2: Name three common materials used as thermal insulators in buildings.

Answer: Fibreglass, polystyrene foam, mineral wool.

Question 1: A wall with a surface area of 10 m² and thickness of 0.2 m is made of a material with thermal conductivity k = 0.04 W/m°C. If the temperature difference across the wall is 20°C, calculate the rate of heat transfer through the wall.

Answer: Q = (k * A * ΔT) / d = (0.04 * 10 * 20) / 0.2 = 40 W

Question 2: A thermal insulator reduces heat loss by 60%. If the original heat loss was 150 W, what is the new heat loss after applying insulation?

Answer: New heat loss = 150 W * (1 - 0.60) = 60 W

Question 1: Describe a simple experiment to compare the effectiveness of two different insulating materials. Include variables to control and safety precautions.

Answer: Use two identical containers filled with hot water, each wrapped with a different insulating material. Measure the temperature change over time with a thermometer. Control variables such as initial water temperature, container material, and volume. Safety precautions include handling hot water carefully and using heat-resistant gloves.

Question 1: A house in a cold climate uses wall insulation with a thermal conductivity of 0.035 W/m°C. The house has a wall area of 80 m² and a thickness of 0.25 m. If the indoor temperature is maintained at 20°C and the outdoor temperature is -5°C, estimate the heat loss through the walls.

Answer: Q = (k * A * ΔT) / d = (0.035 * 80 * 25) / 0.25 = 280 W

Question 1: Explain how the choice of insulation material affects the overall thermal resistance of a building wall. Include the relevant formula in your answer.

Answer: The thermal resistance R of a material is given by R = d / k, where d is thickness and k is thermal conductivity. A higher R means better insulation. Choosing materials with low k and appropriate thickness increases R, reducing heat transfer and improving insulation performance.

Question 1: Identify one technological advancement in insulation that improves energy efficiency in homes or industry. Explain its principle of operation.

Answer: Vacuum insulated panels (VIPs) use a vacuum to eliminate air conduction and convection, significantly reducing heat transfer and improving energy efficiency in building insulation.