• Question: How fast can a child run then a fully grown adult?

    Asked by CrazyScienceUK to Dan on 5 Mar 2018. This question was also asked by lottie.
    • Photo: Dan Gordon

      Dan Gordon answered on 5 Mar 2018:

      Ok I think you are asking how much faster is an adult than a child, if not do ask me again. The world record for the 100m running is 9.58 seconds held by Usain bolt, this means he had an average (mean) speed of 44.7 Kph. The fastest child over 100m at the age of 6 years old was Willie Washington who ran the race in 14.3s which is 25.1Kph. So as we get older we get bigger muscles and also can use them more quickly, we also have more energy stored in the muscles which is needed for sprinting.