By Aeiffert, 9/18/2018
13 viewsVisual reaction time is the amount of time it takes for us to see something and react to it. The average reaction time is 250ms, or 1/4 of a second. That's pretty fast--it takes 300-400ms to blink.
Because reaction time is so fast, it's hard to measure without a slow-motion camera or a computer. In this experiment, however, we're going to learn how we can measure time by using gravity to our advantage. We can do this by using the fact that the earth's gravity acts on objects at a constant acceleration, -9.8m/s^{2}.
To calculate your reaction speed, we're going to use a special physics equation that relates acceleration to distance and time: Distance=.5*Acceleration*Time^{2} (Don't worry if this is confusing, it's from college-level physics!). In our experiment, gravity is the force that's accelerating the meter stick downwards, distance is just the number that we measured in the steps above, and time is what we want to figure out.
By plugging in our number for gravity, 9.8meters/second^{2}, and rearranging the equation, we get: Time^{2}=2*Distance/9.8. Plug in your value for distance and use a calculator to figure out the right side of the equation. Then, find the square root and that's your reaction time!
Hmm... it seems nobody's added a conclusion for this experiment yet. You can suggest one here.
Onions don't actually make people sad... When cut into, an onion releases a gas called "propanethiol s-oxide" that bugs our eyes.