EV3 datalogging RPM challenge (highlights)

I have a challenge for you today I want you to build something that I always tell everyone not to build chicken cups I want you to build a top a spinner a spinning top okay with whatever parts you have in your Eevee three kids I want you to build a spinning top we're going to have a challenge in the class today where we're going to see who can build the spinning top that spins the fastest okay and if you can build a spinning top that spins the fastest we also need you to be able to calculate how fast it is spinning our challenge is that we want to use this and measure how many times that the arms break through the the color sensor okay every time it spins the arm screams past the color sensor it's gonna cut out the light very very very slightly okay very slightly every time it goes past the color sensor so you can see now that it is logging our color sensor so if I'm you can see it like in the small screen now I'm moving the the robot around I'm moving the sensor around if I move it really close to the table because I have a wide table my sensor reading is going go up see on the screen but if I move it away from the table the sensor reading goes down because it's not detecting the reflected light anymore so now this is how we we do it all right what we need to do is once you've found the experiment as soon as you press the middle button on that experiment it will start logging for 10min seconds because we told it that this experiment will last for 10 seconds and it starts as soon as you press the button so what I need you to do is I need you to spin the top spin the top and then press the button for the experiment and then hover over the edge of the arms so then you're tracking the screen it doesn't have to track it for the whole 10 seconds you just have to track it for a few seconds ok and now I need to do something else to make it more obvious because it's it's still very very small and I couldn't really see the bumps exactly so here there's a little error when you hover over the left hand side it's got switch from full scale to auto scale so that's what we need we switch it to auto scale which means that it's going to emphasize those ups and downs will impress that and now this should give you some really cool data and then I press on point analysis and then it adds this line to point analysis so now I need to move my cursor to this line to drag it to that first dip and then I do the same and then I do the same to add another point analysis to the fourth tip so I go here when analysis and then I drag this to my fourth tip so this is how we do it okay so the fourth the fourth tip is at one point one nine seconds one point one nine and then what I do need to do is take away the first dip which was 1.08 1.08 and that equals 0.11 so it takes point 1 1 seconds for me to spin one rotation find out how many rotations that is in one second then it's 1/0 point on one so it's 1 divided by zero point on one that equals the 9 about 9 rotations per second nine revolutions per second and to find out the RPM which is the revolutions per minute then all I have to do is multiply this by 60 so multiply it by 60 mils 545 so when I was spinning my top the fastest it was going at 545 rotations per minute