What you need:
- An empty soda can
- A flat surface such as a table
What to do:
1. Put some water into the soda can. Stand it upright on the table.
2. Tilt the soda can on the lip of its bottom edge and try to stabilize it. You can change the amount of liquid inside the can to help you. About 100 ml of liquid inside should do the trick.
What happens:
After much trial and error, you can make the can lean at a forty-five degree angle. When the can is stable in this position, give it a gentle sideways nudge and you can see it twirl on its edge!
Why?
It all comes down to centre of gravity-the point inside a body, where all its weight is balanced. For an evenly-shaped form, like a ball or even a cylindrical can, the centre of gravity lies at its centre. However, the centre of gravity changes for odd shapes, where it is shifted to the heavier side.
For any object to balance, the centre of gravity should be directly above the point of support. Try this: Stand straight with your feet together. Now, lean forward. You can’t go beyond a certain point because you lose your balance. This happens because as you shift your centre of gravity shifts with you and when it shifts away from your feet-which are the support points-you fall.
Similarly, when you try to tilt the can when it is full or completely empty, it falls over. That is because the centre of gravity of a full or empty can is at the centre of the can. The can cannot balance when its centre of gravity is shifted away from its bottom
But when the can has some liquid in it, the bottom part of the can is heavier than the top. That means the centre of gravity has shifted to the heavier end. In this case, tilting the can still keeps the centre of gravity close to the bottom support and the can doesn’t keel over!
Picture Credit : Google
Leave a Reply