Lever Experiments

WALT ... understand & identify the parts of a lever
...understand how using a lever makes lifting easier
... show where fulcrum goes when balancing and lifting
Aim: To balance and lift loads
Material: a ruler, (pencil), small blocks the same size and large blocks the same size
Method:
1..Make the small blocks balance the big block by moving the fulcrum
2. Show where the fulcrum goes so that one block can lift two blocks
3. Discuss about some levers you have seen and how they work
What we learned about levers:
The ruler was the lever. A pencil was the fulcrum and the blocks became the effort and the load. It was easier to lift the load when the fulcrum is closer to the load. Levers lift objects easiest when the fulcrum is as close to the load end as possible.. We had to move the fulcrum to balance different size loads. When the blocks are the same size on either side the fulcrum is in the middle.

We listened to this story...
Once upon a time there was a king who offered the hand of his daughter in marriage to the prince who most impressed him when the prince came to the castle. However the king had blocked the forest-lined road to the castle with a large boulder. Prince A tunnelled under the boulder to reach the castle, but the king was not impressed. Prince B built a ladder and climbed over the boulder, but the king was still not impressed. Prince C decided to move the boulder completely out of the road so that others could easily pass by. The King was very impressed by this. But ... the question is, how did the prince move such a giant boulder?

After the story we had to think about how he did it. We had to pretend a bucket of sand was the boulder. We were given a plank of wood and went to the sand pit. After much discussion and many changes we found out that the best way ti move the bucket of sand was to use the lever principle. The weight of the bucket of sand changed according to where we put the fulcrum. The closer the weight is to the fulcrum, the lighter it seems to be.