Usain Bolt, the "fastest man on the planet", aims to get his 100 metre world record of 9.58 seconds down to 9.40 seconds. What has mathematics got to say about this quest?
Plus has teamed up with the Royal Society Summer Science Exhibition 2011 to reveal the maths behind some of the science on show. We have chosen two exhibits from this year's participants and produced postcards for people to pick up at the stand, accopmanied by Plus articles to reveal some of the the maths behind them. Read the articles and if you can't make it to the exhibition yourself, you can also download pdfs of the postcards.