Coin Size

Will the size of the coin you drop affect the outcome?

Some useful search keywords might be:

  • kinetic energy
  • potential energy
  • terminal velocity
  • free fall

As explained in the 'Will the height of the building affect the outcome?' section that the size of the building would matter, but it would not need to be huge. The larger coin would have more potential energy and the distance from its falling position to the ground would have to be greater than that of a smaller coin, to convert all of the potential energy into kinetic energy. If the terminal velocity reached its maximum it would be much more dangerous. If the coins were dropped from the same position the smaller coin is likely to reach its terminal velocity faster, due to aerodynamics and such resistances. See the diagram

Aim To show that the size and possibly the shape of a coin will affect the outcome and the damage of the target.
MethodI would like to conduct an experiment using a 5p, 50p, £1, and maybe a £2. I will drop each coin from the same respectable height, into a soft, malleable material, (something like plasticine or possibly a sand box).
Coins: 2p, 5p, 10p, 20p, 50p, £1, £2
Open space that is unaffected by weather or other conditions.


£2 = 3.5mm
£1 = 4mm
50p = 5.25mm
20p = 1.9cm
10p = 5mm
5p = 1mm
2p = 4mm
Our results are not entirely reliable, some coins landed on their side making the indent much deeper, others landed flat and this was only a small indent. The and was also compresed each time the coin landed and this could also have made it an unfair test.

It is difficult to conlude from our results, because of the unfairness of the test. The results are extremely random and therefore inconcluive. In theory, the size of the coin wouldn't really affect the damage done if it was on target, but the bigger the coin; the more height it would need to be dropped from, allowing it to reach its terminal velocity.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License