Video and lesson investigations on the topic of controlling forces. Key concepts include:
- A plank and a block of wood can become a lever system which makes it easier to lift heavy objects.
- Pulleys help with lifting things too.
- Levers make lifting easier.
- The length of the lever and the position of the turning point, or ‘pivot’ are important.
- Pulleys convert downward ‘pull’ into upward ‘lift’.
- Pulleys reduce the effort needed to lift a load.
- Levers and pulleys belong to that class of items known as simple machines.
- Simple machines are able to multiply a force and control the direction and strength of the force to make moving objects easier.
- They are able to concentrate the moving force to where it is needed.