Fast Fact:
Helmets are made of the same composite materials used to build a race car chassis: carbon fiber and kevlar. They weigh about 1.18 kilograms (2.6 pounds) today, which is half their weight 30 years ago. The helmets visor, made of .125-inch- thick lexan, can resist the impact of a stone thrown at 483 km/h (300 mph.)
Objective:
The students will explore the construction of helmets that could one day save the lives of race car drivers.
In the Film:
Throughout the film you see drivers who are wearing full-face helmets. You also see engineers test an Indy car at the Cranfield Impact Centre. Testing helps engineers develop designs that reduce the risk of injury to the driver in case of an accident. A crash test dummy is used to simulate the driver. Improvements in car, track and equipment design have significantly reduced the number of fatal accidents, but racing remains a dangerous sport.
Background:
When an object slows, the energy that is lost must do something, so it exerts force. If the distance over which this force acts is small, the force will be considerable. By using padding in a helmet, the distance over which the force is dissipated is greater. Therefore, the force exerted against a drivers head in an accident is reduced.
Materials:
Different kinds of adhesive materials such as hot glue and tape, soft materials such as styrofoam, airfoam, plastics and bubble sheets, two dozen grade A large-size eggs, aprons.
To Do:
In pairs, the students place an egg lengthwise between the palms of their hands, with their fingers interlocked. Tell them to exert pressure against the ends of the egg. Make sure they are wearing aprons. Then have the pairs of students use different materials to make helmets for the eggs. Create a contest to see who can come up with the safest helmet design. To test their helmets, ask the students to drop the eggs from a height of 10m (11 yards) onto a hard surface. For a control, drop some unprotected eggs onto the same surface.
Whats Going On?
When the students place pressure on the ends of the eggs, they shouldnt break. Eggs held lengthwise are structurally strong. When the unprotected eggs hit the hard surface, they will break. The eggs wearing helmets, which spread the force of the impact over a longer distance, may survive the fall.
Taking It Further:
1. Have the students examine the winning helmets and identify the protective characteristics of these designs. How do these characteristics work? Would they be good to incorporate into a race car drivers helmet?
2. The human brain is encased in its own natural helmet. Ask the students to compare the structure of the brains helmet to the helmets they designed for their eggs. Also, have them compare the structure of the brains helmet to the helmets designed for race car drivers.
3. Give the students time to redesign their cars to hold an egg during the race event. If the egg breaks, the car is disqualified. See how this affects their designs.
