Science -- Your Future, Scotland's Future
SCI-FUN Roadshow Exhibits -- Kinetic Cars
The energy cycle involved in moving the cars around the track
SCI-FUN Roadshow Exhibits -- Kinetic Cars: Energy cycle
How we power the circuit, using the hand drills to drive the cars
SCI-FUN Roadshow Exhibits -- Kinetic Cars: Powering the circuit
n this exhibit you learn about how energy can be converted from one form to another.

Energy cannot be created or destroyed, only converted from one form to another. In the Kinetic Cars exhibit, energy is converted between many different forms.

Turning the handle is movement energy, called Kinetic Energy. This generated electricity, or Electrical Energy, which powered the cars. The cars’ movement is, again, Kinetic Energy.

We can take it back further than this though. You required energy to turn the handle. The energy in your muscles is stored as a chemical called ATP, and is a form of Chemical Potential Energy. You converted this into Kinetic Energy when you moved your muscles.

Your body reacts sugars in the food you eat with oxygen, which releases carbon dioxide and water in a reaction called respiration. Respiration releases energy which your body uses to make ATP. The sugar used in respiration is another kind of Chemical Potential Energy.

The food we eat is a combination of animal products, such as meat, fish, eggs or dairy, and plant products, such as fruit, vegetables and cereals. Plants create their own sugar from carbon dioxide and water, also releasing oxygen, by photosynthesis. It is this sugar that we eat (or that other animals eat before we eat them). Plants get energy to do this from sunlight: Light Energy. Almost all energy on Earth originally comes from the Sun.

So the Sun produces Light Energy. Plants use this for photosynthesis to make Chemical Potential Energy. We eat this, and convert it into another kind of Chemical Potential Energy. We use this to move our muscles as Kinetic Energy and turn the handle. This generates Electrical Energy, which moves the cars with Kinetic Energy.

We can trace the conversion of energy in various day-to-day processes. For example, powering a car: light energy from the sun is used by plants for photosynthesis to make chemical potential energy. Plants are compacted down over millions of years to form oil, from which we extract petrol, a different kind of chemical potential energy. Petrol burns releasing heat energy, which creates kinetic energy to move the car.

1 Energy cannot be ________ or ________.
2 What do we call movement energy?
3 What is produced from sugar and oxygen in respiration?
4 What energy is needed for photosynthesis?
5 Where does most energy on Earth come from?
6 Do you know how the Sun makes energy?

1 See if you can work out all the energy conversions in some processes. Ideas might be: powering your mobile phone, a wood fire or how your digestive system works. Some might be harder than others.
2 Energy is not always converted efficiently, and sometimes energy is converted into kinds of energy that we don’t need, as well as the kind we do. For example, sometimes when we want light, we also get heat. Take a modern energy-saving lightbulb and an old-fashioned incandescent lightbulb and put them into two similar lamps or light-fittings (make sure the lamp is switched off before you put the bulb in). Switch on the bulbs then measure the temperature of each using a thermometer. Which is warmer? If you have an energy monitor, measure how much energy is wasted.