- For over 50 years, scientists have been using crash test dummies to test car safety.
- Scientists hope that virtual crash test dummies will give them more information and help them to improve car safety.
- Body systems
Spark a discussion
- What makes an object move/stop moving?
- Can you name some examples of forces in everyday life?
- What happens to the people and objects inside a car when it stops abruptly?
- What sort of forces act on a car during a crash?
- What sort of forces act on a person during a car crash?
- What safety features do cars have? How do they work?
- What are crash tests and why are they useful?
- What are crash test dummies? Why do we use them?
- What are the advantages of virtual crash tests over physical tests? Are there any disadvantages?
- How else can virtual testing be used in science and engineering?
Crash test dummy
Show this visual before the film, ask the children to explain what is happening, and discuss the purpose of crash tests and dummies.
Show this visual after the film and discuss how seat belts and car/booster seats reduce the impact of forces in a crash.
Forces on a car
Show this visual after the film and discuss the forces acting on a moving car, and how these change during a crash.
Show this visual after the film to reinforce key scientific language.
INVESTIGATE how the speed of a collision affects the force of an impact using toy cars and ramps.
Other activity ideas
- RESEARCH the latest developments in car safety, and other technologies designed to protect people from car crashes and other collisions.
- CREATE a safety leaflet about the importance of wearing seat belts, using booster seats, and not distracting drivers.
- DEMONSTRATE the principle behind airbag by challenging the class to create soft landing pads for dropped eggs.
- DESIGN a vehicle with safety features that will reduce the impact of forces during a crash.
Duration: 90 minutes
- 3–5 books (to prop up the card to form a ramp)
- Large sheets of white paper
- Coloured pens
- 2 toy cars
- Planning an investigation activity sheet
- Ruler/measuring tape
- Protractor (optional)
This activity reinforces the students’ understanding of forces and collisions, by asking them to plan and conduct their own toy car crash tests.
- Ask the class to recap the purpose of crash testing. Remind the class that these tests are repeated many times, and the conditions of every test are carefully controlled. This enables scientists and engineers to gather lots of information about what happens during a crash. Tell the class that they are now going to plan and carry out their own crash tests.
- Organise the students into groups, and give each group the resources.
- Ask the groups to plan an investigation into how speed affects the force of a collision, using the Planning an investigation activity sheet. Note: Encourage the students to come up with their own questions, setups and methods, and help them to tailor their investigations accordingly. For example:
- To make the car travel faster, the students could release it from further and further up the ramp (using the ruler or measuring tape to measure the distance each time). The higher up the ramp the car is released, the longer it has to build up speed.
- To make it easier to observe and record the results of each collision, the groups could place the sheet of white paper on their testing surface, and draw around the starting position of the car at the bottom of the ramp. Then, once each test crash is complete, they can draw around the car’s final position, using a different colour of pen for each test to make it easier to keep track.
- Remind the groups that only one variable should change each time – in this case, the distance that the car travels down the ramp before colliding with the second car. All other variables must stay the same: the position and angle of the car, the angle of the ramp, and so on.
- Give the groups time to carry out their investigations. Ask them to repeat each test three times, to check that their results are consistent. If they have taken measurements, help them to calculate an average and then plot the data in a graph.
- Discuss the results as a class. You may want to ask the following prompt questions:
- What happened to the cars in each collision?
- How did increasing the distance affect the results?
- Did you get the exact same results when you repeated the tests?
- If not, why do you think that is?
- Were there any variables you weren’t able to control fully?
- How could the investigation be improved?
- What does this investigation suggest about how speed affects collisions?
- Ask the groups to write a paragraph summarising the results of their crash tests. The groups are likely to find that the collisions push the stationary car backwards and cause the other car to change direction. The faster the car is moving at the point of collision, the larger the force of impact and the more noticeable the results. They may even find that one or both of the cars is knocked over by the larger collisions. They can also draw a labelled diagram showing the forces that act on two cars during a head-on collision.
Ask the class to investigate how the angle of the collision affects the results. They can do this by changing the position of the ramp in relation to the stationary car. A protractor can be used to measure the exact angle, allowing them to compare the effects of a head-on collision, a 15 degree collision, a 45 degree collision and a 90 degree collision.
- A force is a push, a pull, or a combination causing a twist. A force is required to begin motion and to change its direction or speed.
- In a car crash, the human body is subjected to extreme forces that can cause serious injury. Without any form of gradual deceleration, bodies can be brought to an immediate halt at fatal force.
- Airbags and seatbelts are safety devices designed to lessen the impact of these forces. These safety devices reduce the average deceleration and hence the average force acting on a human body involved in a car crash.
- Crash tests allow engineers and scientists to carry out controlled collisions. The resulting data can be used to make improvements to vehicle design, or influence road safety laws. Crash test dummies are used to study the effects of a car crash on drivers and passengers.
- Virtual crash tests allow engineers to repeat tests quickly and at a fraction of the cost of a physical crash test. That’s because there’s no need to build and then destroy a prototype. Virtual tests can also provide information that physical testing cannot. For example, virtual human bodies can be used to study the effects of collisions on internal organs.
- Crash test dummy
- A life-size model of a person, used in tests to simulate what would happen in a car crash.
- Virtual testing
- Using a computer simulation to carry out tests or conduct an investigation.
- The act of two objects hitting each other with force.