Vocabulary N°4

1. Inclined Plane: A straight, slanted surface that is not moved when it is used.

• An example of the inclined plane is a ramp.

2.Screw: An inclined plane wrapped around a central bar.

• My aunt use a screw to support the table.

3.Wedge: One or a combination of two inclined planes that is moved when used.

• A wedge may have one or two slanted surfaces.

4.Compound machine: A combination of two or more machines.

• Scissors is an example of compound machine.

5.Efficiency: A ratio of the work done by a machine compared with the work put into the machine.

• To calculate the efficiency you write a ratio.