JAMB Physics 2024 Paper

Concept:The quantity of heat transferred depends on the thermal capacity of the material and the change in temperature it experiences.Explanation:The formula for the quantity of heat is $Q = C \times \Delta\theta$.Here, $Q$ is the quantity of heat, $C$ is the thermal capacity, and $\Delta\theta$ is the temperature change.First, find the change in temperature: $\Delta\theta = 80^\circ\text{C} - 60^\circ\text{C} = 20^\circ\text{C}$.A change of $20^\circ\text{C}$ is equal to a change of $20\text{ K}$, so $\Delta\theta = 20\text{ K}$.Substitute the given values: $Q = 400\text{ J K}^{-1} \times 20\text{ K}$.Therefore, $Q = 8000\text{ J}$.Convert the result to kilojoules: $Q = \frac{8000}{1000} = 8\text{ kJ}$.Answer:The quantity of heat is $8\text{ kJ}$, so the correct answer is D.