Page 141 - York Global Science 6 - Physical Science

Physical Science

Let’s Learn

Simple machines are mechanical devices that make work easier. They do
this by:

• changing the direction of a force
• making a force stronger

• making the force work over a longer distance.

The amount of energy needed to do the work does not change, but by
changing the forces, the work becomes easier.
Look at these simple machines. How do they make work easier?

Lever

A lever means we need less force to move a load, but the force must
work over a longer distance. A load that is closer to the fulcrum needs less
work to move it. A longer lever makes the work easier. Levers change the
direction of a force, so pushing down on a lever lifts up an object.

Inclined Plane

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