In this episode, Nigel asks, “If you crash your car, are you better off in a small, modern, 5-star safety rated car or something big and solid?” To find out, Nigel makes clever use of models – supermarket trolleys, egg cartons and jelly brains – to explain some fundamentals in physics.
Let’s get our heads around the basics of smashing stuff into stuff.Nigel Latta
Nigel Latta Blows Stuff Up
Watch Series 1/Episode 4: Car Collisions
Science ideas and concepts in Episode 4: Car Collisions
In between the drama and humour, Nigel introduces a number of important science concepts. This episode explores:
- Newton’s second law of motion – force equals mass times acceleration (F=ma)
- kinetic energy – the energy of motion, which means a moving object can do ‘work’ on anything it hits
- models in science – using representations of reality.
Resources on the Science Learning Hub provide and in-depth – and safer – means to further explore these concepts.
Newton’s second law of motion
Nigel uses shopping trolleys to demonstrate that mass and speed determine the amount of force in a collision (force = mass x acceleration). When the trolleys have the same mass and the same speed, the force of the collision is shared between the two trolleys. Change the mass – either with a weight in the shopping trolley or by using a heavier car – and the collision outcomes also change.
Nigel explains that all moving objects have kinetic energy. When a moving object collides with something else, the kinetic energy is transformed. With car crashes, the kinetic energy is transformed via the heat, sound and the deformation of the vehicles.
Kinetic energy is reliant on the mass of an object and the velocity at which it moves. Imagine being hit by a ping pong ball being rolled along the ground (low mass and velocity) compared with a cricket ball that has been hit with a bat (high mass and velocity). The cricket ball will hurt more when it hits you, that is, when it comes to rest.
Learn more about kinetic energy
Science classifies energy into two categories – kinetic (moving) and potential (stored). Kinetic energy can be electrical energy, radiant energy, sound energy or motion energy. These articles explain some different types of kinetic energy.
This activity identifies forms of kinetic and potential energy and uses formulae to calculate the energy of an object. It is suitable for secondary level.
Calculating potential and kinetic energy
Models in science
Nigel uses shopping trolleys to model collisions, egg cartons to model crumple zones and jelly to model the human brain. These simple representations provide easy, inexpensive and safe ways to explain the science behind car collisions, safety features and the impacts on the human body.
Nature of science
In science, a model is a representation of an idea, object, process or system. Models are central to how scientists work, both in their research and when communicating their explanations.
Nigel and the team at Holmes Solutions later use real cars to test their predictions.
Using models in science
Models are central to how scientists work. Scientific modelling can take many forms – from a simple globe to complex computer models. The following articles are a few of the Hub’s many examples of how and why scientists use models.
ANCAP (Australasian New Car Assessment Program) provides consumers with advice and information about vehicle safety. Visit their website to learn more about safety ratings, crash tests and safety features.
Engineering experts from Holmes Solutions helped Nigel test the trolleys and cars. Visit their website for stories and videos about the safety tests of objects ranging from public artwork to redwood tree houses to roadside barriers.
Use literacy resources from Connected to support science understanding about kinetic energy.
Harnessing the wind Connected Number 3 2010
Where shall we put the turbine? Connected Number 3 2010
Power alternatives Connected Number 3 2010
A new life for old machines Connected Number 3 2007
Sounds in space Connected Number 2 1998
Learn more about Connected.