Unit 7I Energy resources Lesson 6

Energy resources lesson plans

Lesson 6 energy and food

Aim – Where does all our energy originate from?

5 minutes Starter Students have previously studied food chains. Ask them what normally starts any food chain? Why do we have to have a plant at the start? Where do plants get their energy from?

20 minutes Trace the food chain ending in a glass of milk back to its source – the sun. The energy in the foods we eat can be traced through a food chain with the Sun’s energy at the start of the chain.

Similarly, trace the energy of a moving car or bus back to the sun – fossil fuels were living organisms that transformed and stored the suns energy.

Students answer Q 1 and 2 p.107

30 minutes Use p 107 as stimulus material for a discussion on how we can use energy well.
Pupils may wish to present the points that arise in the form of display material or a debate.

National curriculum links: Sc4 5a/b/c energy resources

Grading:

Level 5 Describe the type of energy that an object has or is using

Level 6 Describe how energy is transferred from the Sun to other energy resources

Unit 7I Lesson 5 Energy and food

Energy resources lesson plans

Lesson 5 energy and food

Aim – Calculate the energy content of two different brands of crisp

5 minutes – recap of the last two lessons about renewable energy and fossil fuels.

This lesson is has two parts – In the first part discuss and identify our energy related need for food. In the second part is an experiment.

10 minutes Starter Living things such as people transform the energy provided by food into other forms
We need heat to maintain our body temperature. Energy from food is transformed into movement including the movement needed to make our lungs breath air and our heart pump blood. The food we eat combines with oxygen to make the energy.

If we eat more than we need the food is converted into fat.

You need to remember that humans convert the chemical energy from food into movement (kinetic) energy and heat energy.

Some types of food provide more energy than others. The energy content of food can be measured in units called Joules. If you throw an apple about 1 metre into the air then you use up about 1 Joule of energy.

30 minutes Main activity and experiment

Comparing the energy content of two different types of crisp

Measure out 10 ml of water and pour it into a boiling tube.
Carefully place the tube in a clamp stand.
Use a thermometer to record the starting temperature of the water.
Carefully light the crisp using a Bunsen burner and hold underneath the boiling tube.
Once the crisp has extinguished record the finishing temperature of the water.

The specific heat capacity of water is approximately 0.42 Joules/g. We can work out the energy content of each crisp by using the equation…

Energy content = temperature change of water x 42 (10 grams of water)

Megan and Georgina's energy content = 19 x 42 = 798

Energy content of 100g of crisps = Energy content/mass of wotsits x 100.

Megan and Georgina's energy content of crisps = 798 Joules / 1.5 grams x 100 = 53,200 Joules

Do our results agree with what the food labels on the crisps say?

According to the label a 100g of Wotsits contain 2,270,000 Joules.

What!?! So where did all the energy go? Thats what we will be finding out in the next unit 'Heating and Cooling'.

Grading

Level 4
List the eight forms of energy

Level 5
Describe some energy transfers including some which involve living things

National curriculum links

Sc4 5a Energy resources

Sc1.2g- observations

Lesson 4 Renewable energy

Energy resources lesson plans

Lesson 4 renewable energy

5 minutes – recap of the last lesson about fossil fuels.

10 minutes Starter – Setting up the solar panel practical

Most of the energy on earth comes from the Suns rays. It is then converted into other forms of energy that we are familiar with on Earth. However as an alternative to fossil fuels we can use the Sun’s rays directly as an energy resource – this is called solar power. You will be setting up an experiment to investigate how colour affects the solar panels that heat water in some peoples homes.

1. Wrap a measuring cylinder with different coloured sheets of paper (inc black & white).

2. Fill the cylinder with 50 ml of water, use a thermometer to measure the starting temperature of the water.

3. Place the cylinder next to a desk lamp with a 60 W bulb and wait for 25 mins.

25 minutes Main activity Table and other energy resources

Prepare a table to record the results of the experiment and draw a diagram of the equipment. Mr Cuthbert will then ask for your ideas on other forms of renewable energy. What are the advantages and disadvantages of these?
http://www.bbc.co.uk/schools/ks3bitesize/science/physics/energy_transfer_6.shtml for more information.

Home work set for this week. Design a poster about 1 form of renewable energy that shows one advantage and one disadvantage.

20 minutes – Practical results.

4. Measure the final temperature of the water in the measuring cylinder.

5. Were there any changes? Were some colours better than others?

6. Answer questions a – d on pg 103 of the textbook.

Recap of key points in the lesson.

Grading

Level 3
Name some renewable energy resources

Level 4
Give some examples of how to save fuels

Level 5
Identify which sort of energy an object has, or is using
Describe how renewable energy resources can be used to make electricity
Describe how renewable energy resources can be used to make heat

Level 6/7
Explain the advantages and limitations of different energy resources

NC Scheme of work - Sc4 5a/b Energy resources

SC1 Scientific enquiry - Sc1. 2a,g,h,I,j,k,m,o,p Investigative skills – obtaining evidence