Question 22
FA student compares how quickly hot water cools in two containers, X and Y. The walls of the containers have the same thickness but are made of different materials.
The student pours the same volume of water at 80 ∘C80\ ^{\circ}\text{C}80 ∘C into each container and measures the temperature every 2 minutes.
The Figure shows the results.
Figure
a.[1]
Use the graph to find the temperature of the water in container X after 4 minutes.
b.[2]
Calculate the average decrease in temperature per minute for the water in container Y over the 10 minutes.
c.[2]
Explain which container has walls with the higher thermal conductivity.
Use information from the graph in your answer.
d.[2]
Give two variables, other than the ones already given, that the student should keep the same so that the comparison is valid.
3.2 Dissipation and efficiency Questions
100 exam-style questions on Edexcel GCSE Physics 3.2 Dissipation and efficiency, covering 3.2.1 Dissipation of energy, 3.2.2 Reducing unwanted energy transfers, 3.2.3 Efficiency, and 3.2.4 Increasing efficiency. Each one has a worked solution and a mark scheme showing where the marks go.