Heating up and cooling down 0 Overview Connecting to the Curriculum Marking Student Responses Further Resources This task is about heat conduction. Question a) John filled four glasses with hot water from the tap. He placed a different type of stirrer in each one. He left the stirrers in the water for two minutes, then he touched the top of each stirrer. Metal spoon Plastic spoon Wooden ice-block stick Waxed paper straw A B C D i) Which one felt the hottest? A B C D ii) Explain why the stirrer you chose felt the hottest. Question b) Sally made some hot soup and placed equal amounts in each of four different containers. She left these on the kitchen table. A B C D i) Which soup would show the greatest temperature decrease after 10 minutes? A B C D ii) Explain why the soup in the container you chose would cool more quickly. Level: 3 Curriculum info: Science, Knowledge, Physical World Keywords: physics concepts, energy, heat, conductors, surface area Description of task: Task: Select which stirrer would feel hottest and explain why, and in which container soup would cool fastest, and explain why. Assessment focus: heat conduction. Making Better Sense: Conduction/Convection/Radiation Answers/responses: Y7 (03/1998) a) A easy b) Because metal conducts heat more readily. moderate c) D easy d) The surface area exposed to the air is greater, e.g., the soup is more spread out therefore more air can get to it/easier for the heat to escape. moderate Heating up and cooling down II
