Our topic this term is castles. We have been learning about technology in the middle ages. First we revised some work on energy and forces from last year.
Then we did some experiments to learn about levers and how they are used to do work. We learned that the longer the lever the less effort needed to lift a heavy load but you can’t lift it very far. If you put the load on the long end and the effort on the short end you have to use a lot of force but you can lift the object higher.
There are three kinds of levers, a first class lever, a second class lever and a third class lever. First class levers are the most efficient kind then second then third.
We have been learning how castles were attacked and defended. Gatehouses made the entrance to the castle stronger.
Drawbridges could be pulled up when under attack. We made model gatehouses with working drawbridges. A drawbridge is a third class lever.
Siege machines like the trebuchet were used to attack castles. We made model trebuchets. A trebuchet is a first class lever.
Then we enjoyed testing our trebuchets. They worked really well!! A trebuchet is a first class lever.
We did research on castles and made some super posters which are on our class wall.