Answer 1:
I do not know the answer to your question although it seems reasonable to expect faster reaction times in video game players. Instead of me answering your question, let me propose that you measure reaction times as part of your science fair project. One idea you can use for this measurement is based on the free fall of objects and therefore adds some interesting physics application to your project. Let us have first a little background in the physics of freefalling bodies. If an object starts from rest, then the vertical distance traveled is given by the formula: d= (1/2) g t^{2} where g has a value of 32.2 ft/s^{2} or 9.81 m/s^{2}. if using units from the International System instead of the British or Imperial System. t stands for the time of fall. For example, the distance an object falls (starting from rest) during the first 2 seconds is: 0.5x9.81x4 m = 19.62 m = 64.37 ft = 772 in. By doing some algebra, you can solve the above equation for t: t = sqrt (2d/g), where sqrt means "take the square root of" (I encourage you to verify this by doing the algebra!) And so, be able to find that, for example, the time it takes an object to fall 2m = 6.56 ft = 78.7 is t = 0.639s (rounded to 3 figures) which is quite a short time. Human reaction times are even shorter: about 0.2 s. Of course this reaction time varies from one individual to the next, and also, in the same individual it varies from one day to the next or even from one hour to the next and this is why it would be very interesting to include the measurement of reaction times as part of the project. Going back to our original equation, the distance an object falls (from rest) during 0.2s is, using 0.04 for the square of 0.2: 0.5x9.81x0.04 m = 0.1962 m = 19.62 cm = 7.72 in so it is a distance that can be measured my means of an ordinary school ruler. One clever idea I found in a Physics textbook ("Physics" by Resnick and Halliday) many years ago is to use a ruler as both, the falling object and the length measuring device. You have the subject (whose reaction time you want to measure) place her forearm on a table with her hand just outside the edge of the table. She then keeps her thumb and index with a separation of around 0.5 cm while you hold the ruler vertically from the top at a height such that the lower end is at the same level as the upper part of the subjects thumb and index, just between the fingers but without touching them (see attached photos). Now, without prior notice (this is very important so you dont want to give yourself away), you release the ruler so that the subject has to first realize the ruler is now falling, and second, catch the ruler by closing her fingers without lowering the hand (that is why she needs to rest her forearm on top of a table). If, for example, you find that the upper part of her fingers holding the ruler is placed at a reading of 18.5 cm on the ruler, then by using our second equation above we find her reaction time to be (after converting 18.5 cm to 0.185 m): t = sqrt(2x0.185/9.81) s = 0.194 s.We can go one step farther and build a ruler (like the one shown in the photos) where we have readings directly in seconds (fractions of a second, actually) instead of having to read the length in cm and then, performing the calculation each time you perform a measurement. All we need is build a table, like the one below, that will allow us to draw the lines and numbers on a blank ruler (a strip of wood, plastic or aluminum about 30 or 40cm in length): < t (in seconds)  length (in cm)  0.06  1.8  0.08  ____  0.10  ____  0.12  7.1  . . .  . . .  0.20  19.6  0.22  ____  0.23  ____  0.24  28.3  
I filled in some of the values on the column on the right of the table above so that you can build the rest of the table (fill in the blanks) using the first formula (for d). Look closely at the photos so you can have a better idea of what the ruler will look like. Feel free to write if you are not sure of your results before constructing your "Reflexometer" ruler. I really hope you include reaction times measurement as part of your project. Please let me know you did! Picture_1 Picture_2
