Energia ülekandmise tsirkus

Mida ütlevad uurimused

In teaching energy the BEST resources have adopted a framework based on ‘energy stores’ and ‘energy pathways’ which is advocated by, amongst others, (Boohan, 2014), (Millar, 2014) and (Tracy, 2014). As Millar (2014) says, this approach “is not perfect - but it is adequate and significantly better than [approaches] based on lists of ‘forms of energy’.” A clear guide to this approach can be found on the Institute of Physics’ website (Institute of Physics).

(Rogers, 2018) highlights that the precision in the language we use about energy is important. Because energy is an abstract concept we have to use words to describe it. He advises giving students opportunities to practise using language precisely, to help them develop an accurate model of what is happening. This practical activity gives students the opportunity to observe and describe how energy is transferred in a range of examples.

The Institute of Physics identify four ways that energy can be transferred: mechanically, electrically, heating by [moving] particles and heating by radiation. It is, however, more important to describe the mechanisms or processes that transfer energy, than it is to give each transfer a label. When explaining how energy is transferred, Tracy (2014) recommends that we focus on describing the processes and mechanisms involved. He suggests that trying to identify the ‘energy’ in each step is just a labelling exercise that can get in the way of a clear understanding of what is happening. Describing how friction and drag cause heating introduces students to the dissipation of energy. (Millar, 2005) suggests that to make sense of the law of conservation of energy, students need to know that in almost every event there is some heating, whether desired or not, and a consequential increase in the heat store of the surroundings.

A summary of the BEST approach to teaching energy can be found on the Best Evidence Science Teaching home page which is on the STEM Learning website (Fairhurst, 2018).

Kuidas seda töölehte kasutada

This practical activity gives students the opportunity to practise applying their understanding and to clarify their thinking through discussion. To support this, students should complete the practical circus in pairs or small groups.

Listening to individual groups as they work often highlights any difficulties they might have. These can often be overcome, through a whole class clarification or redirection part way through the activity.

Asking students to report their findings at end of the practical work is a useful check. After a group has fed back, it might be helpful to model an even better answer. You could do this, for example, by asking another group to add to, or clarify, the first observation. Then ask another group to sum up the important part of the observation, and so on.

Differentiation

Using the recording sheets can help some students organise their observations so they can more easily focus on the science. If some students are working with a teaching assistant, then a list of prompt questions for the TA could help to make this activity more purposeful.

Some students may benefit from being challenged to draw a Sankey diagram for each energy transfer.

Equipment

For the class, one or two sets of:

Wind-up toy
Ball
Toy car
Ramp (x2)
Bar magnet (x2)
Battery powered fan (or similar)
Kettle 250 cm3 plastic beaker
0-100 oC thermometer
Set of work-station instruction cards

Technician notes

This is the same practical circus as the one used in the response activity: Energy stores circus in the first progression toolkit for this key concept. The difference is in how the students engage with each practical station.

There are six practical stations that students move between. For large classes it may be helpful to have two of each one. Similar equipment may be substituted to achieve the same learning outcomes.

Wind-up toy: a wind-up toy that moves
Ball rolling down a slope: a wooden ramp and a ball to roll down it (helpful if the ramp has sides), possibly with something at the end to catch the ball
Pushing magnets together: pair of bar magnets that are fairly strong and with clearly marked north seeking poles
Battery powered fan: a battery powered fan – or other battery operated device that produced movement
Pushing a toy car up a slope: a toy car and a wooden ramp – with something at the top to stop the car shooting off
Hot water cooling: 250 cm3 plastic beaker, thermometer and a kettle. These are best situated near a sink. (Helpful to provide a few spare beakers, so they can be left to cool before pouring away)

Health and safety

Because students will be moving between each practical station extra care needs to be taken about relatively low risk activities:

Pushing and pulling objects can make people move in unexpected ways and some students may have a tendency to become boisterous when interacting with equipment in this way.

The practical station with hot water should have a kettle for heating water and a sink. Using a plastic beaker filled half-full means that it is safer to lift and pour out, in comparison to a glass beaker.

Practical work should be carried out in accordance with local health and safety requirements, guidance from manufacturers and suppliers, and guidance available from CLEAPSS.

Uuri allpool kirjeldatud olukordi. Vasta küsimustele.

Energia salvestamise tsirkus

Energia võib üle kanduda erinevaid teid pidi.

Kas sa oskad neid kõiki näha ja arusaadavalt selgitada?

Ohutus

Hot water can burn -> keep beakers in the middle of a clear table.
Spilt water can make the floor slippery -> wipe up spilt water straight away.
Pushing and pulling objects can make people move in unexpected ways -> check nobody is too close and move with care.

Katsevahendid

Different work-stations are set up around the room

Töö käik

At each work-station:

Read the information card
Carry out the investigation
For each energy transfer describe how the energy is transferred. (The best answers are clear and short, but with lots of detail.)
Can you spot any energy transfers that are not shown on the information cards?

Learning focus:	When a force makes things change it mechanically transfers energy between different energy stores. Friction transfers energy mechanically into a heat store of energy.
Observable learning outcome:	Identify different ways that energy can be transferred Identify where energy is transferred by rubbing Describe how energy can be transferred in different ways Explain how energy is almost always transferred to the heat store of the surroundings
Activity type:	Response, application and practice - practical
Key words:	Energy store, energy transfer, mechanically, friction, electrically, heating, energy store chemical, elastic, gravitational, heat, kinetic