Question 1: Define thermal energy store and explain how it differs from other energy stores.

Answer: A thermal energy store is the energy stored in an object due to its temperature, arising from the random motion of particles. It differs from other energy stores, like kinetic or potential energy, because it specifically relates to microscopic particle motion and heat energy.

Question 2: Describe the mechanism by which heat is transferred through conduction.

Answer: Heat is transferred through conduction when particles in a material vibrate and pass their energy to neighboring particles, transferring thermal energy from the hotter region to the cooler region.

Question 1: Calculate the amount of thermal energy (in joules) stored in 2 kg of aluminum at a temperature of 80°C. (Specific heat capacity of aluminum = 900 J/kg°C)

Answer: 1,440,000 J

Question 2: A metal rod with a length of 1.5 meters and a cross-sectional area of 1 cm² is heated, causing a temperature increase of 50°C. If its thermal conductivity is 200 W/m°C, what is the rate of heat transfer through the rod? (Use Fourier's law: Q̇ = (kAΔT)/L)

Answer: 66.67 W

Question 1: List three safety precautions that should be followed when conducting an experiment involving heating a metal object.

Answer: Use heat-resistant gloves, ensure proper ventilation, and keep flammable materials away from the heat source.

Question 2: Identify the independent and dependent variables in an experiment measuring the rate of heat transfer through different materials.

Answer: Independent variable: type of material; Dependent variable: rate of heat transfer.

Question 1: A container of water at 25°C is heated to 75°C in 10 minutes. Describe how the thermal energy stored in the water changes during this process and what factors influence the rate of heating.

Answer: The thermal energy stored in the water increases as its temperature rises from 25°C to 75°C. Factors influencing the rate include the power of the heat source, the mass and specific heat capacity of the water, and heat losses to the surroundings.

Question 1: Explain how understanding thermal energy stores is important in designing thermal insulation for buildings.

Answer: Understanding thermal energy stores helps in designing insulation that minimizes heat transfer, keeping buildings warm in winter and cool in summer, which improves energy efficiency.

Question 2: Describe a technological application that relies on controlling thermal energy transfer, and explain its significance.

Answer: Thermal power plants use controlled heat transfer to convert thermal energy into electricity. Efficient heat transfer and insulation are crucial to maximize energy output and reduce energy loss, making power generation more sustainable.