Describe whether one machine is more divide their lists into these categories. different pieces of efficient than another. equipment. The Describe what power means, and the Exploring: Power ratings results should be relationship between watts and Students examine various items of linked to the joules/second. domestic electrical equipment to find power ratings of Securing their power ratings. Ask students to the equipment. Use Sankey diagrams to compare find a connection between the type of appliances or processes. energy transfer that the device Calculate energy efficiencies. carries out and its power rating. Explain why the efficiency can never be greater than 100%. Explaining: Drawing Sankey diagrams Exceeding Guide students through the process Use the formula relating power, energy of converting data about energy and time (in W, J and s). transfers into a Sankey diagram. Evaluate energy-saving appliances or modifications. Plenary: Thinking about power and efficiency Odd One Out: electricity, heating, chemical. (Possible answers: chemical is the only one that is used as a name for an energy store; heating is the only one that is both a useful and a wasteful way of transferring energy.) Lesson 8Ke: Paying for energy Learning objectives Exemplar teaching activities Differentiation Resources Maths skills Practical skills Developing Starter: Domestic fuel bills Exploring: Energy Resources n/a Students Recall that electricity and mains gas Ask students to work in pairs to come survey from 8Ke complete an are charged for on the basis of the up with as many different Follow up the Exploring energy survey. energy transferred. explanations for this statement energy survey by Science. Explain why power companies use the as they can: ‘One household spends asking students kWh as a measure of energy. twice as much as another on gas and to produce a Recall some advantages of low-energy electricity each year.’ leaflet explaining appliances. the best ways to Securing Exploring: Energy survey save energy at Use data to consider cost efficiency by Ask students to carry out an energy home.
Describe whether one machine is more efficient than another. Describe what power means, and the relationship between watts and joules/second. Securing Use Sankey diagrams to compare appliances or processes. Calculate energy efficiencies. Explain why the efficiency can never be greater than 100%. Exceeding Use the formula relating power, energy and time (in W, J and s). Evaluate energy-saving appliances or modifications. divide their lists into these categories. Exploring: Power ratings Students examine various items of domestic electrical equipment to find their power ratings. Ask students to find a connection between the type of energy transfer that the device carries out and its power rating. Explaining: Drawing Sankey diagrams Guide students through the process of converting data about energy transfers into a Sankey diagram. Plenary: Thinking about power and efficiency Odd One Out: electricity, heating, chemical. (Possible answers: chemical is the only one that is used as a name for an energy store; heating is the only one that is both a useful and a wasteful way of transferring energy.) different pieces of equipment. The results should be linked to the power ratings of the equipment. Lesson 8Ke: Paying for energy Learning objectives Exemplar teaching activities Differentiation Resources Maths skills Practical skills Developing Recall that electricity and mains gas are charged for on the basis of the energy transferred. Explain why power companies use the kWh as a measure of energy. Recall some advantages of low-energy appliances. Securing Use data to consider cost efficiency by Starter: Domestic fuel bills Ask students to work in pairs to come up with as many different explanations for this statement as they can: ‘One household spends twice as much as another on gas and electricity each year.’ Exploring: Energy survey Ask students to carry out an energy Exploring: Energy survey Follow up the energy survey by asking students to produce a leaflet explaining the best ways to save energy at home. Resources from 8Ke Exploring Science. n/a Students complete an energy survey.