Resources: Class presentation and handout.
Handout: Information on James Watt for historical context. Definition of power and model calculation. Practice calculation for power, including changing units and the subject of the equation. Practice converting SI units.
The presentation has pictures of 5 household appliances. Ask the students discuss their energy usage and place them in order of the biggest user of electricity to the smallest. Use this to lead a discussion of why they may use so much energy.
(Data from energy savings trust website 2022: https://energysavingtrust.org.uk/top-five-energy-consuming-home-appliances/)
Use the handout to briefly explore what the industrial revolution was and how the steam engine - pioneered by Boulton and Watt - changed the world. Practice the power calculations and rearrange the formula. Discuss SI units and reading questions with care. Ensure that the students understand the difference between energy and power.
(Energy is the capacity to do work. Power is the rate at which energy is transferred or work is done.)
Practice the calculations for power and rearrange for time taken to transfer and for energy. Use power ratings to compare the power ratings for a range of household appliances. Ensure that the students understand the rating is in watts and it tells us how much energy is transferred per second. Discuss that some appliances are only on briefly whereas others run all day. Power is useful for comparing appliances.
Career Film: This is Beth Slingsby. Beth works as a Physicist for National Nuclear Laboratory.
Expert Film: This is Edward Reeves, who works as a Project Manager for National Nuclear Laboratory. Edward talks about power.
Use the handout to explore the industrial revolution and discover how the steam engine - pioneered by Boulton and Watt - changed the world. Practice the power calculations and rearrange the formula. Discuss SI units and reading questions with care.
Challenge Task: Ensure that the students have understood the definition of power by asking them to compare 2 machines that are lifting the same mass at a different rate. Which one does more work? Which one has the greatest power and why?
Use the summative quiz to assess students' learning.
Go back to the starter: How can we reduce our energy usage. Why is this so important? What would have the biggest impact?
Get students to write a green pledge: 2 things they will do at home to reduce energy wasted.