It is important that you get used to manipulating the various units of measurement and maths numbers that you will come across on the course. This puzzle will help you to work out relationships and ratios between units. We measure speed in metres per second (m/s) (gas burns at .35 m/s for example) We measure the distance around the edge of a circle (circumference) by using the formula 2 x 3.14 x radius (Radius is the point from the middle of a circle to the edge) Anything starting with the word KILO means a thousand times (e.g 1 KILOgram = 1000grams) The Question: I was waiting to pick up my son the other day and I saw a windmill working hard in the strong wind. Having nothing better to do, I decided to see how fast the tip of the blades were travelling. Each blade is 7m long (from the centre to the tip), they take 3 seconds to complete 1 circle and that to convert KM/h to MPH you simply multiply the speed by 0.6 At what speed was the tip of each blade travelling?