Theme C: Les vehicules qui roulent

• Axle: A shaft at the centre of a wheel.

• Chassis: A frame upon which a vehicle is built.

• Drag: The resistance bodies experience when they move through air or water.

• Fair Test: A test in which only one variable at a time is manipulated or changed.

• Friction: A force of resistance which is encountered when two objects move against each other.

• Inclined Plane: A flat surface that is tilted.

• Inertia: A property of matter which makes a body remain in the same state. Inertia keeps a body that is at rest, stationary and a body that is moving to keep moving in the same direction at the same speed.

• Lever: A rigid piece of material that pivots around a fixed point and changes the direction of the push or pull.

• Linkage: Being joined together at a point or along a plane. The link can be a fixed immovable connection, a point of pivot or an energy transfer system where by movement is transferred from one part of a machine to another.

• Machine: A device for doing work in which a force (effort) which is applied at one point, overcomes a force (load) at another point.

• Mechanical Advantage: A ratio of effort size to load moved. A machine that reduces the effort needed to move a load generates a mechanical advantage.

• Potential Energy: Energy which is stored by an object. A compressed spring has potential energy.

• Speed: The measure of how fast an object moves.

Wheel: A circular frame of hard material that may be solid, partly solid, or spoked and that is capable of turning on an axle.