1. Drag 03 Apr 2011

2. WALT Describe what drag is and some examples of drag reduction in everyday life Explain drag using the particle model Carry out a fair test to investigate the relationship between shape and drag

3. Keywords Drag The force of resistance acting on an object moving through air or water Air resistance The force of resistance acting on an object moving through air Water resistance The force of resistance acting on an object moving through water Streamlined Something that has a smooth shape designed to reduce drag

4. What is a force? A force is a …………. or a ………….

5. What is a force? A force is a push or a pull.

6. A force can make something change ……………… or ……………….

7. A force can make something change direction or shape.

8. What will the car do? What are the forces?

9. What will the car do? The car will accelerate ! Pull (engine force) Friction + Air resistance

10. What will the car do? Pull (engine force) Friction + Air resistance

11. What will the car do? Pull (engine force) Friction + Air resistance The car will move at a constant speed

13. Speeding Up Why do things move?

17. Faster Why are they wearing costumes?

18. Faster

19. Faster What do these two images have in common?

20. Fuel consumption Pages 134/135 of Exploring Science. A lorry is traveling at a constant speed of 70mph • are the forces balanced or unbalanced? • what 3 forces act on the lorry? • if we reduce the air resistance, what is the effect on fuel consumption? • can you tell me 2 other advantages of lorries fitting deflectors

21. Fuel consumption Pages 134/135 of Exploring Science. A lorry is traveling at a constant speed of 70mph • are the forces balanced or unbalanced? • what 3 forces act on the lorry? • if we reduce the air resistance, what is the effect on fuel consumption? • can you tell me 2 other advantages of lorries fitting deflectors [cheaper food, less carbon emissions]

22. Wind tunnel/cyclist http://www.bbc.co.uk/learningzone/clips/aerodynamics-reducing-air-resistance/276.html While you are watching sketch the outline of any shapes you would like to test in our streamlining experiment.

23. Particle model Using the particle model to explain drag OK – now I want you to take 30 seconds to read the card in front of you in pairs. I suggest you each read alternate paragraphs. Now pick an A and a B – I want A to test B by asking the 5 questions in italic. Then switch. Continue until you are both answering all questions correctly.

24. Cyclists reducing drag http://www.bbc.co.uk/learningzone/clips/air-resistance/10595.html 2min I would like you write down the 3 ways of reducing air resistance you see in this video, and at least 2 design features you see here that reduce air resistance.

25. Investigation Do a fair test to investigate which is the best shape to reduce drag. You have been given a worksheet on which to record your results. You each have a cylinder of wallpaper paste, a beaker, a stopclock, plasticene, and a balance to weigh it.

26. Graphing Draw a bar chart of velocity vs. shape, placing the bars in order of velocity, so the slowest missile is first bar. Above each bar draw a small diagram of the shape. Some: if you also did the range of masses, do a line graph showing velocity vs. mass.

27. Pack away http://www.bbc.co.uk/learningzone/clips/the-sharkskin-swimming-suit/11036.html

28. WALT Describe what drag is and some examples of drag reduction in everyday life Explain drag using the particle model Carry out a fair test to investigate the relationship between shape and drag