Imagine a restaurant with a swinging door leading to the kitchen. Two waiters try to push the door open from opposite sides at the same time. One holds a huge bowl of spaghetti. The other balances a tray of dishes. If they both push with the same force, the door doesn’t move. But if the waiter with the spaghetti does not push as hard as the other waiter, the door swings open. And crash – spaghetti flies everywhere!
When equal forces push on an object from opposite sides, that object is in equilibrium. An object that is in equilibrium is balanced. It won’t move or tip over unless an extra push is added from one direction.
A force called gravity pulls all objects downwards, towards the centre of the earth. Every object has its own centre of gravity, the spot where it can be balanced. If you support an object at its centre of gravity, it will be in equilibrium.
Ask a grown-up to help you carefully stick a small fork into a small potato, with the top side of the fork facing upwards. Next, find a pencil that is longer than the fork.
Push the pencil into the other side of the potato until about 2.5 centimetres sticks out above the fork. Balance the pencil tip on the edge of a table, with the fork extending below the table. The potato stays balanced because its centre of gravity is actually in the pencil tip!
Picture Credit : Google
