Teachers' Notes
Teachers' Notes
This section forms the framework for pupils' work using this online resource. The idea is to establish the challenge at the start. It may seem that making a model aircraft which flies furthest/longest is a good challenge. However, it may be more demanding to require models to land close to a target, or to follow a curved path past a vertical post. It is unlikely that you will be able to make powered models, and you may have to impose restrictions, e.g. on available materials and mode of launching. You might wish to establish a shared challenge by discussion with a class in a different school. You will probably want to intervene at intervals so that pupils can report on progress; you can then ensure that they are consulting and learning from the other sections of this resource. Back to the 'Challenge of Flight'
Blowing on Paper This activity shows that a piece of paper can appear to be sucked up by fast-moving air. It's better to think of it as being pushed up by the slow-moving air underneath (i.e. the pressure of the slow-moving air underneath is greater than the pressure of the fast-moving air above). The aerofoil shape (see the next activity 'Investigating an Aerofoil Shape') is designed to exploit this effect. Lift is caused in two ways: 1. By the wing deflecting air downwards as it moves along (which results in a reaction force upwards on the wing) since the front edge of the wing is slightly higher than the rear edge. 2. By the pressure effect, described above, of the flow of air round an aerofoil-shaped wing. Back to 'Blowing on Paper'
Investigating an Aerofoil Shape This is a tricky activity. You may wish to set up your own demonstration to show the students if theirs don't work very well. The wing cross-section needs to be asymmetrical. You could set up a symmetrical version to show that no lift is generated. Back to 'Investigating an Aerofoil
Shape'
Make Your Own Helicopter Which direction should you spin your model helicopter to make it go upwards? Investigate differently-shaped strips. What happens if you use a longer strip? What happens if the strip is shorter and wider? Strips should be cut lengthways from a plastic bottle. You may wish to cut the ends off a bottle to make this easier for your students. The hole could be made using a hole punch, a nail, or the point of the scissors. It should be smaller than the pencil. The strip should be twisted by holding the two free ends and twisting in opposite directions. Instead of pencils, you could supply lengths of thin dowelling. This activity gives students an opportunity to investigate a variety of different shapes. Long, thin strips tend to be too floppy; short fat ones do not generate much lift. Back to 'Make Your Own Helicopter'
Swimming and Diving The important point here is to emphasise that when a swimmer pushes water backwards, the result is a forward force on the swimmer. In a similar way, an aircraft moves forwards by pushing air backwards. Back to 'Swimming and Diving'
Thinking about Weight and Gravity The relationship between mass, weight and gravity is tricky. This activity simply asks students to think about the origin of weight in the gravitational pull of the Earth (or any other massive body). By thinking about situations where gravity has a different strength, students can start to grasp this relationship. The activity avoids the distinction between mass and weight. Back to 'Thinking about Weight and Gravity'
Make Your Own Hot Air Balloon Only a large bag made from the thinnest plastic is likely to rise, since the plastic itself has to be lifted too. An alternative is to make a bag from tissue paper. Cut out six sections as shown, and glue them together. Leave the bottom edge open.
Warning: Naked flames must never be used for these hot air balloons and the heat source must never be attached to the balloon. Back to 'Make Your Own Hot
Air Balloon'
Weighing In and Out of Water Part 1 encourages students to understand the idea of weight by weighing by hand. Part 2 makes the point that a measuring instrument like a newtonmeter can give you more reliable results than human judgement. Part 3 encourages pupils to understand the upthrust force on an object in water. (You could discuss their own experience of this when bathing in the sea or in a pool.) For objects less dense than water, students will have to decide their own method of measuring the upthrust. This activity could be extended to a consideration of density and floating/sinking. Back to 'Weighing In and Out
of Water'
Fast fall, slow fall This activity includes two ways of investigating drag (air resistance). In one, students are required to minimise this force; in the other, they must maximise it. Starting the activity: With the class, discuss the ideas presented on the activity page. They will already have some ideas about drag, and how it can be altered. They might talk about the design of fast cars and aircraft; they might mention parachutes, including those used for braking the space shuttle. (For ideas about how to discuss drag, see the drag page in Forces of Flight.) This activity is intended to formalise your students' ideas about the factors which effect drag, including shape, area and speed. Using Forces of Flight: The factors which effect drag are discussed in the drag pages. It is probably best to encourage students to start on one of the challenges before they start looking at Forces of Flight. Then they can use the reference pages to help them develop their designs, and to formalise the language they use to explain their findings. The two challenges give students plenty of opportunity to develop their ideas of fair testing. Challenge 1: You will need to impose some restrictions, which you can discuss with the class. Students might be restricted to using a standard sheet of paper, which they may only fold. Alternatively, they might be allowed to cut it, use glue or sticky tape, or attach other objects such as paper clips. This would allow them to investigate the effects on drag of shape (including streamlining), area and weight. Challenge 2: Here it will be essential to use additional materials. Students are likely to devise techniques such as parachutes, or adding propeller blades to make the stone spin. (You could use a rubber bung as a safer and more standard alternative to a stone.) Again, you may wish to come to an agreement with the class about the extent to which the stone can be modified. What do you know? From their investigations, students should be encouraged to draw up a summary of the factors which they believe effect the force of drag. A full understanding of drag is difficult. The force itself depends on several factors, including speed. (Compare this with weight, which for practical purposes only depends on the object's mass, so that we can regard it as constant.) The effect of drag depends on both the object's weight and its mass. (To find out how the object will accelerate, we need to know the difference between weight and drag, and then take account of its mass.) For most students at this level, it is sufficient to think of drag as a force which tries (or tends) to slow down anything which is moving. Summary of ideas about drag:
Back to 'Fast Fall, Slow Fall'
Ideas in the bath These questions will give students an experiential feel for the factors which effect drag. Some suggested answers:
Back to list of activities
Falling through water It is difficult to time an object falling through the air. A ball bearing or marble will be slowed down by viscous drag as it falls through water, and this is easier to measure. Traditionally, this experiment is done with glycerine or a similar viscous liquid, rather than water, but this is very messy. Water is an alternative, but the effect is not so dramatic. Suggested procedure: With a vertical cylinder of water, mark a starting line near the top of the cylinder. Students can time the fall of ball bearings from this line to the bottom of the cylinder. The ball bearings should be dropped from a standard height above the surface of the water. With a sloping ramp, timing is easier because the ball moves more slowly. However, the effects of drag may be less marked. Anticipated results: Larger ball bearings fall faster than small ones - the effect of drag is less. A glass marble will fall more slowly than a ball bearing of the same size, because its weight is less; drag depends on the size and shape of the object, not its weight. Modelling clay can be used to make lighter spheres of the same dimensions. They can be re-shaped to be more streamlined, or to increase drag. Back to 'Falling through Water'
Compare the Flights This activity is intended as a summative exercise, to encourage students to use their understanding of forces to discuss developments in aircraft design leading up to Alcock and Brown’s flight. Points to discuss with your students: There are many ways of presenting a comparison of the two aircraft. Annotated drawings and tables both work well. Students should be encouraged to use appropriate scientific terminology. External influences also played a part. World War I encouraged the development of more reliable aircraft; competition from airships and the availability of large prizes were also very influential. Sources of information: The First Flight and Long Flight sections of this resource. Back to 'Compare the Flights'
Compare the Aircraft This activity is intended to give students a structure for their exploration of the website, particularly the First Flight and Long Flight sections. Its focus is the two aircraft, and this gives an opportunity for students to find out about the development of aircraft technology in the early decades of the twentieth century. Students can find information in the form of technical data about the two aircraft, and details of their power and control systems. They are asked to think of a way of presenting this information; this might be in the form of annotated diagrams, or tables, or some other form of graphical presentation. Students could write individual pieces of information on slips of paper, colour-coded for the two aircraft, and then find ways of arranging the slips to create a clear impression of how the two compare. Back to 'Compare the Aircraft'
Flying through History This activity is intended to set the context for students' work on flight, and to give them an opportunity to access the collections databases. Points to discuss with your students: You will probably want to restrict the timespan which students are considering. The suggested titles indicate some possible timespans. There are many ways in which students could present their ideas and findings, including drawings, text, cartoons, etc. Many sources of information are available; you may wish to restrict your students to the use of the materials contained in Flights of Inspiration, or you may wish them to extend their research beyond this. An example of a flight timeline can be found on the Science Museum's website. Students should go beyond producing a simple chronology of events. They should be encouraged to find out about the scientific and technological developments which made the events possible. A simple understanding of forces will enable them to make some sense of these developments. This can be developed later through the relevant activities associated with Your Own Flight. Back to 'Flying through
History'
High Speed Crossing High speed crossing - answers A
B
C
D
E
Five minutes to cross the Atlantic This activity gives students a chance to use a range of source materials to recreate a sense of Alcock and Brown's historic flight. You will need to ensure that they focus on details of the flight itself, rather than the details of what went before and what happened after. It may be appropriate for students to prepare a written script, which they can then act out to the class. Alternatively, they might jot down notes about different aspects of the flight whilst looking through the source material, and then improvise their performance. Aspects of the flight they might consider:
Follow-up work
Finally, they might think about their own five-minute drama. Was everything they included in it based strictly on the available evidence? Was any of it invented for the sake of the drama? Back to '5 Minutes to Cross
the Atlantic'
Flight Log This could be an introductory activity to a study of the science of flight. This activity gives students an opportunity to extract information from a range of sources. They should be encouraged to include numerical data, and to make calculations of speeds. You may wish to supply information which will allow them to make comparisons with a modern transatlantic flight by a passenger aircraft. Information from different sources may be contradictory. Students should be encouraged to make a critical assessment of the information they find, perhaps by adding footnotes to their work. |
