hello welcome back to the game or channel my name is mr. Clifford and today we are going to be looking at the required practical of reaction time which is for combined science and additionally GCSE way all do so we are going to be investigating reaction time reaction time is to find us in time taken to respond to a stimulus we are going to be changing the amount of caffeine consumption so we're going to have zero caffeine or some caffeine caffeine is a stimulant so in theory it should increase your reaction time and that's what we're going to investigate I depend therefore always what we're going to measure and as I said it's going to be the reaction time which we will convert to milliseconds in a table later on our control variables are what we're going to keep the same so that's going to be your arm position the person who obviously is receiving the ruler the ruler the height of the drop and the amount of caffeine so we're gonna plant the results table here we have caffeine and naik I think we have our tries in the left-hand column followed by distance and then time in milliseconds which we're going to convert once we've got our results then we have no caffeine and the same try distance and time in milliseconds we're just going to plan to mr. Tucker who is about this drink or coke so it has now been 20 minutes since mr. Tucker has ingested the caffeine so now we're going to test his reaction time with our breather so I'm just going to place the ruler above his fingers needs to be at the same place every single time so in there gonna go No so that has gone to 140 so that is 4 no 136 13 centimetres so we can fill that in here thirteen centimeters which is 163 milliseconds we're just gonna repeat it one more time it's the same again in the same place so just above and that has given us let's say that is 18 centimeters so 15 centimeters which leaves us at 190 so we have filled in the night caffeine as we did that before mr. Taku ingested the KY thing or the coke so as you can see from our results table the distance was shorter on the caffeine where the caffeine was ingested then where the caffeine wasn't interested this means that reaction time was quicker in when the caffeine was adjusted then when the caffeine was not interested and you can sell this by the time so you can see that 163 192 is less than 202 and 212 that means that the reaction time is shorter which means that the caffeine has obviously had a stimulating effect on his reaction time and therefore it is shorter