Fairgrounds are popular with many children, and they are full of examples of physics in action. This week’s science corner encourages students to experiment with the science behind roller coasters.

Each group of students should be given some clear plastic tubing, string or bag ties and a marble that will easily fit through the tubing.

Encourage your students to create a roller coaster for the marble from the plastic tubing. To make this really easy you could set up a piece of wire netting a couple of centimetres proud off the wall, taking care that the sharp edges of the netting are covered in tape to protect the children.

Alternatively, attach the tubes to stable furniture such as a table. Once the children have created a roller coaster allow them to try it out using a marble. Does the marble get to the end of the roller coaster? Where does it get stuck? Why does the marble get stuck in certain places? Encourage your students to experiment with the tubing to make a roller coaster that works.

When the marble is put at the top of the roller coaster it has potential energy. As it rolls down the slope the potential energy is converted into kinetic energy and the marble speeds up. As soon as the tube goes upwards, the kinetic energy is converted into potential energy and the marble slows down. Some of the energy is lost because of friction. The marble cannot travel to a height greater than its starting height - this is a starting point for discussing the conservation of energy.

Once your students have experimented with different roller coaster designs, talk to them about how to make one that works really well. How does the initial height of the marble affect how far the marble travels? Could they think of ways of giving the marble more energy at the start? What should they avoid doing? Using a longer piece of tube encourages the students to design the ultimate roller coaster - using the conclusions of their experiments to make sure it works first time.