Mousetrap drag racer
Materials needed, per student or group
- Mousetrap (not a rat trap) or strong elastic band
- 2-4 CDs or large round plastic lids
- 4 smaller card wheels
- Strong tape or a glue gun
- Template (above) printed on an A4 sheet of thin card
- Second sheet of thin A4 card
- Assorted other building materials (optional)
- Pencil or long dowel
- Safety goggles
Working with mousetraps has some important health and safety implications, but it is an activity that is routinely used in American schools in classes of students as young as 8 years old. Use elastic bands if you have concerns over mouse traps.
This activity should not require students to set or release the trap directly. The trap is set by turning the wheels and the energy is later released in a controlled way.
Glue the template onto the second sheet of card to give extra strength before folding the design to creade the body of the racer.
Wearing safety goggles when building and launching the mousetrap cars will help protect the students’ eyes from whipping strings or broken equipment.
NB: Do not use rat traps, which are even stronger and could potentially break a finger if sprung accidentally.
For a more inquiry-based activity, challenge the students to make a car that uses a mousetrap or elastic band to power it along a 5 metre track. Decide if you want to limit their materials or give them a free rein. Consider ‘pricing’ each material and get them to design their car within a set budget.
- What design elements must be common to all cars? Are there any parts of the design that can/cannot be customised?
- Where is energy ‘lost’? Students will see this as loss of power to the car, but it is important to stress that the energy from the mousetrap is not lost but is dissipated, e.g. into heat or sound as a result of friction.
- What made the class design that travelled fastest or furthest so effective? What hampered the design that performed the worst?
- Consider redesigning your drag racer to make it more effective (e.g. longer ‘pull bar’, more or fewer wheels, wider wheels, more or less weight).
- How can you make the steering adjustable?
- How can you make the wheels grip the floor more effectively? (A strip from the middle of a balloon can be stretched over the wheels to increase traction.)
- How can you increase the speed or distance covered?
- Can you make a mousetrap-powered boat? What would you need to consider?
Links to everyday life
As you nervously sit in a roller coaster car as it’s winched up the track, you are gaining potential energy. The moment the car starts to move downwards, under the influence of gravity and the roller coaster’s motor, you experience kinetic energy.