STELR Group Investigations into Energy Transformations

Energy Transformation Investigations

Station A : Mystery toys

  1. As a group, discuss how you think these toys work. You may use annotated diagrams or a sentence for each of your explanations.
  2. Show in diagrams or other representations, the energy transformations that you think take place when each of these toys work.

Station B : Hand cranked generator

  1. What did you discover about how the generator works?
  2. a) What happened when you reversed the magnet?

b) What happened when you removed the magnet?

c) What do you think the magnet does?

  1. Show the energy transformations you think took place as the generator operated the fan. Use a diagram or other method of representation.

Station C : A chemical battery

If you put two different metals into a solution of common salt (sodium chloride), an electric current is produced. The two metals in this experiment are zinc and copper. To detect the current you will have to use a micro ammeter or a galvanometer. The needle will move if there is current.

  1. What changes, if any, did you observe in the solution when the circuit was set up?
  2. Did the galvanometer needle move?
  3. Did the globe light up?
  4. What might you conclude about the size of the electric current produced?
  5. Show the energy transformation(s) you think took place when the circuit was complete, in a diagram or other representation.

Station D : Pelton wheel

  1. Was the Pelton wheel able to generate enough electricity to make the LED and the lamp operate?
  2. What did you discover about the way the leads need to be connected for the LED and the lamp?
  3. How do you think the Pelton wheel works?
  4. Show the energy transformations you think took place when the Pelton wheel causes a light to go on, use a diagram or other representation.

Station E : A commercial battery

A single battery should be called a cell, not a battery. A battery consists of two or more cells joined together to produce a greater amount of electricity. Cells contain special chemicals that react with one another to produce an electric current when the cell is part of a complete circuit. The chemicals in a commercial cell are dangerous, so they are sealed in. NEVER TRY TO OPEN ONE!

  1. What did you discover in this investigation?
  2. Show the energy transformations you think took place when each of the following devices was connected into the circuit, using diagrams or other representations.

a) Fan

b) Buzzer

Station F : Wind Turbine

A wind turbine is a device that uses wind to generate electricity. The wind causes the blades of a turbine to rotate, which in turn causes a copper coil to rotate inside a magnet. This produces an electric current in a wire.

  1. Use diagrams or other representations to show the energy transformation(s) you think takes place when the wind created by the fans starts the wind turbine moving.
  2. What further energy transformations do you think take place if the buzzer works? Outline them in a diagram.
  3. What effect did turning the fan to high have on the lamp? Suggest a reason for this.
  4. Suggest a change you could make to the set-up to cause the sound of the buzzer to be louder. Justify your suggestion.

Station G : The solar panel

A solar panel consists of a set of solar cells. Each cell converts light energy into electrical energy.

  1. What energy transformations do you think take place when light shines on the solar panel and causes the fan to rotate? Show these transformations in a diagram.
  2. What energy transformations do you think take place when light shines on the solar panel and causes the lamp on the testing station to illuminate? Show these transformations in a diagram.
  3. Suggest one way you could modify your set up to make the fan turn faster?

Station H : A ‘mini-kettle’

  1. Use a diagram to show the energy transformations you think take place once the battery is connected into the circuit.
  2. What is one change you could make to this set-up to make the increase in the temperature of the water greater? Discuss.

General Questions

  1. Name a common device in which the following energy transformations take place:

a)Electrical energy to sound energy.

b)Electrical energy to light energy.

c)Electrical energy to both light and sound energy.

d)Electrical energy to heat energy.

e)Mechanical energy to electrical energy.

f)Electrical energy to mechanical energy.

  1. Do you think it is possible to rank the commercial chemical battery, the simple chemical battery made from the metals and solution, the Pelton wheel and the hand cranked generator in order of their ability to generate electricity? If not why not? If so, in which order do you think they should be placed? Explain how you arrived at your conclusion.
  2. Can you suggest an alternative way to represent energy transformation? This could involve for example, modelling, simulations or role plays. What are the benefits of using diagrams or representations other than just words to explain what we observe and think?

Energy Transformation Investigations.docx13/05/2010