could be fun at MJC.

WHY

If you work out the math it's maximum height in meters = 9.81/8*t^2where t is the time from throwing to catching measured in seconds.in words: "9.81 divided by 8 times the number of seconds squared"or more simply, approximately: 1.2*t^2For ease of calculation at the time you could think of it as slightly larger than the time squared.If you recorded the right time, used the precise rate of acceleration due to gravity (9.80665 m/s^2), and did this in a vacuum (i.e. no air resistance), you'd get the exact height.

...but why can't you just use .5 * 9.81 * t^2 = distance travelled (from the 'top' of the throw to the ground)

That's exactly what I did. Remember, distance travelled from the top to the ground is only 1/2 of the time recorded, so:d = 1/2 * 9.81 * (1/2t)^2d = 1/2 * 9.81 * 1/4 * t^2d = 1/8 * 9.81 * t^2d = 9.81/8 * t^2