Lesson Plan

2. Explore gravity and air resistance

05_03_06

Learning Outcomes

To understand the forces of gravity and air resistance

Higher: Is able to explain 'drag' and how it affects the speed of an object falling
Middle: Can identify some examples where both gravity and air resistance are forces acting against one another
Lower: Is able to understand what gravity and air resistance are

To know how to make an effective parachute

Higher: Can test and evaluate the variables to improve the design of their parachute
Middle: Can design and make their own parachute
Lower: Understands the necessary features needed for a good parachute

Activities

Lesson Starter - Engage

Method:

Lesson Recap Starter: Think back to the last lesson. What are the highlights of the life and work of Sir Isaac Newton?

Lesson Starter: Watch the film then discuss what helps the Discovery spacecraft slow down.


Children may consider previous learning about Newton's Laws to help them understand motion and forces

Resources:

Presentation - Starter Slide.

The Story - Explore and Explain

Method:

Answer questions and take part in activities during the presentation.

Galileo's gravity test.

Literacy:  Using the letters of the word GRAVITY, create a mnemonic using each letter as the start of a sentence. Using the mnemonic, you should explain how gravity and air resistance works!

Key Concept:

During this unit, each lesson contains a key concept question housed in the '30 Second Challenge' slide. To help children master this content so the knowledge moves from their short term memory to their long term memory, at the beginning of the follow on lesson the question from the previous lesson is revisited. 

The questions covered during this unit include:

What are the highlights of the life and work of Sir Isaac Newton?

What is the difference between gravity and air resistance?

What's the difference between water resistance and friction?

Explain how a lever and a pulley can make it easier to complete a task. Use an example to explain your answer.

When riding a bike up a hill, how do gears work to make pedalling easier?

Why do certain objects sink or float and what does density have to do with it?

Resources:

Presentation

Lesson Expert - Explain

Method:

Expert Film: Sam talks to Karina Hilbolling from Norwich Astronomical Society about gravity and air resistance.

How we deliver the Gatsby Benchmarks:

2 - Learning from career and labour market information:  Pop along to Developing Experts career’s zone to find out about jobs in your area.

4 - Linking curriculum learning to careers: This unit showcases careers that relate to forces. Access our 360° virtual work tours.

7 - Encounters with Further and Higher Education: Pop along to Developing Experts career’s zone to find out about training providers in your area.

Resources:

Expert Slide

Lesson Assignment - Elaborate

Method:

Paper Drop

  1. Cut out a piece of paper that is 16cm x 16cm, clip a paperclip to the paper. Stand a metre stick upright or affix it to a wall.
  2. Hold the piece of paper at the top of the metre stick and release it. Use the stopwatch to time how long it takes the piece of paper to reach the floor. Record the time in the table.
  3. Fold the piece of paper in half to make an 8cm x 16cm rectangle clip the flap together with the paperclip. Drop this from top of the metre stick as before.
  4. Repeat this folding the paper in half each time and use the paperclip to keep the paper together.

It is important to fold and not cut the paper to size to ensure the mass of the paper remains the same throughout.

Make a Parachute 
Alternatively students could try their own parachute investigation. This is more time consuming and more challenging to make a fair test.

Pupils should plan their investigation beforehand in order to ensure their investigation is structured.

  1. Pupils should suggest a hypothesis or prediction.
  2. Pupils should then suggest what their independent variable (what they are changing) and dependent variable (what outcome they are measuring) will be.
  3. Pupils should list their control variables (factors they are keeping the same, to ensure a fair test).
  4. Pupils can the write out a recipe like method and then carry out their investigation.

Suggested investigations

  • How does the weight of parachutist affect the time taken to fall?
  • How does the material the parachute is made from affect its time taken to fall?
  • How does the height dropped affects time taken to fall?
  • How does the shape of parachute affect time taken to fall.

Resources:

Paper Drop
Metre stick
Stopwatch
Paper
Scissors
Paperclip

Make a Parachute 
String     
Plastic carrier bags     
Sticky tape     
Tangerines (or similar)     
Scissors
Handout

Lesson Log - Evaluate

Method:

Quiz
With their talk partners, the children are to go through the quiz at the end of the presentation and answer the questions.

Resources:

Quiz in presentation

Assessment

Questions to Ask During the Lesson

Do children take and record readings accurately?  
Can they use findings to refute or support scientific ideas?  
Do they use scientific vocabulary?  
Can they describe how gravity pulls things towards Earth?  
Can they explain that air resistance slows falling objects, and therefore the surface area of an object affects their speed?

Mark Allocation

Quizzes available in pupil zone.

Unit knowledge organiser and test available in unit documents.

Choral Response Questions/ Phrase Suggestions

The force that tries to slow things down when are moving through the air is called....
Air resistance happens when...
An example of something we use to balance gravity and air resistance is...(a parachute)

Teacher Mastery

The Science Behind the Science:

Gravity is the force that keeps all planets within the solar system in orbit around the Sun. It also helps the moon to stay in orbit around the Earth too. Gravity is basically when objects that have mass are attracted to one another. Many people believe that it was Isaac Newton’s initial observation of the apple falling from the tree that inspired the theory around gravity. Albert Einstein later adapted this theory to his theory of relativity. 

Would you believe me if I said that every object has gravity in it? It’s just that some of these objects have a lot more gravity than others do. Can you think of one? Yes, the Sun. The Sun has a huge amount of gravity which explains why it can keep all planets in orbit around itself. This gravitational force keeps Earth at just the right position to allow us to get the necessary amount of light and warmth to survive. Gravity is proportional to how big an object is. For example, the larger an object is, the more gravity it has. This can be used to explain why the Sun has so much gravity.  

We need gravity to prevent us from flying off here and there. Gravity keeps us grounded to the floor. Do you remember the football example? If you kick a football, it goes flying in the air. This football would continue to fly if it was not for gravity. Gravity is what brings the ball back to the ground. Here’s a cool fact to remember: the tides that you see in the ocean are as a result of the moon’s gravity. 

Air resistance is the force that acts in the opposite direction to which an object is moving. So basically, air slows down things that are trying to or are already moving. Another word for air resistance is ‘drag’. The quicker you move, the bigger the resistance. A cool way to remember it is by taking into consideration what happens when you ride a bicycle. When you are pedalling fast, the air is also pushing back against your body. This is air resistance. If it is windy on your bike ride, it would be very difficult to pedal through the air as it is pushing back against you with a greater force. This is why you don’t see many cyclists on a windy day.   

Curriculum Fields

National Curriculum

Explain that unsupported objects fall towards the Earth because of the force of the gravity acting between the Earth and the falling object.

Curriculum Of Excellence

Forces, electricity and waves - Forces - By investigating how friction, including air resistance, affects motion, I can suggest ways to improve efficiency in moving objects. SCN 2-07a

International Baccalaureate

Forces and Energy: the study of energy, its origin, storage and transfer and the work it can do; the study of forces; the application of scientific understanding through inventions and machines.

Enquiry Skills and Approaches

Carrying out comparative and fair tests.

Working Scientifically Skills

Planning different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary

CBSE

Grade 6 - Motion and Measurement of Distances