# Conservation of Energy and Efficiency

Quantify energy, using box diagrams, and explain the idea of conservation of energy. Identify useful and wasted energy transfers and calculate efficiency from written questions and Sankey diagrams.

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What unit is energy measured in?

1/6

Q2.Which of these statements about energy is true?

2/6

Q3.A light bulb has energy transferred to it electrically. How is energy wasted by a light bulb?

3/6

Q4.A washing machine transfers energy to its thermal and kinetic stores to wash clothes. How is energy wasted by a washing machine?

4/6

Q5.Match the energy store to a real life example.
• kinetic energy
• gravitational potential energy
• chemical energy
• elastic potential energy
• a book high up on a shelf
• a football moving quickly
• a bow pulled back to fire an arrow
• a banana

Where you see this icon you can drag and drop! If you are using your keyboard select and move using space and the arrow keys.

5/6

Q6.Match the energy transfer to a real life example.
• electrical transfer
• mechanical transfer
• heating transfer
• a crane lifting an object
• a frying pan warming up on a hob
• a microwave oven using microwaves to heat food
• a circuit

Where you see this icon you can drag and drop! If you are using your keyboard select and move using space and the arrow keys.

6/6

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What unit is energy measured in?

1/6

Q2.Which of these statements about energy is true?

2/6

Q3.A light bulb has energy transferred to it electrically. How is energy wasted by a light bulb?

3/6

Q4.A washing machine transfers energy to its thermal and kinetic stores to wash clothes. How is energy wasted by a washing machine?

4/6

Q5.Match the energy store to a real life example.
• kinetic energy
• gravitational potential energy
• chemical energy
• elastic potential energy
• a banana
• a bow pulled back to fire an arrow
• a football moving quickly
• a book high up on a shelf

Where you see this icon you can drag and drop! If you are using your keyboard select and move using space and the arrow keys.

5/6

Q6.Match the energy transfer to a real life example.
• electrical transfer
• mechanical transfer
• heating transfer
• a crane lifting an object
• a frying pan warming up on a hob
• a microwave oven using microwaves to heat food
• a circuit

Where you see this icon you can drag and drop! If you are using your keyboard select and move using space and the arrow keys.

6/6

# Video

Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:

• Click "Close Video"
• Click "Next" to view the activity

Your video will re-appear on the next page, and will stay paused in the right place.

# Worksheet

These slides will take you through some tasks for the lesson. If you need to re-play the video, click the ‘Resume Video’ icon. If you are asked to add answers to the slides, first download or print out the worksheet. Once you have finished all the tasks, click ‘Next’ below.

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Energy stores and transfers (Part 2)

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.What is the law of energy conservation?

1/6

Q2.What is energy dissipation?

2/6

Q3.How is energy commonly dissipated?

3/6

Q4.How can efficiency be calculated?

4/6

Q5.How is efficiency often shown?

5/6

Q6.What is the purpose of a Sankey diagram?

6/6

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Energy stores and transfers (Part 2)

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.What is the law of energy conservation?

1/6

Q2.What is energy dissipation?

2/6

Q3.How is energy commonly dissipated?

3/6

Q4.How can efficiency be calculated?

4/6

Q5.How is efficiency often shown?

5/6

Q6.What is the purpose of a Sankey diagram?

6/6

# Lesson summary: Conservation of Energy and Efficiency

## Time to move!

Did you know that exercise helps your concentration and ability to learn?

For 5 mins...

Move around:
Jog

On the spot:
Chair yoga