- Take a normal pencil and jab it into a potato with as much force as you can.
- What happens? It does not penetrate through to the other side
- Now try the straw. Jab the straw through the potato with the same force.
- It travels straight through and come out the other side.
- Why? Because the same amount of force is being applied to a much small area – the rim of the straw.
November 22, 2013