3 seconds a drop is very very off. Clearly your understanding of gravity is off, but all of your other math/physics is right. Gravity is 32 ft/second/second, so in 1 second you fall 16 feet, resulting in typical airtime off the normal drop (say 8 feet) to be roughly .75ish seconds (speed increases the more you drop so you cover more in the last increment of time). Jumps can be interpreted slightly different, you get double the time for the same height achieved as drops. Say you get 16 feet up on a domination drop, then your airtime would be 2 seconds because of the above mentioned constants. Close though, the other stuff about rotation on wheels, moments of intertia, centripietal force, etc was all pretty cool.

Oh, and yes, pvssys

Come again?

32ft/sec/sec is the acceleration of gravity. The very instant you leave a drop, your rate of decent is 0ft/sec, and the more time you spend airborne, the faster you fall.

As you should know, the formula for distance traveled knowing only initial velocity, acceleration, and time is D=V0*t+at^2. Since initial velocity is 0 for a drop, you get D=at^2. This gives the distance fallen from an initial velocity of 0 in 1 second as 32ft...duhhh, not 16ft.

Using the above equation, we can calculate normal airtime for a drop like Phantom. Let's use 8ft like you did:

8ft=(32ft/sec^2)t^2

t^2=(1/4)sec^2

t=0.5 second

Now, I really don't feel like calculating how many seconds Dom's Denial, Road to Nowhere, Anthem, the jumps, etc. would take. But if anyone wants to try, use the formula I used, multiply that by the number of times you hit the drop per day, add it to the other drops you hit, times it by number of times you visit a season, etc. For jumps, estimate the height you get off the jump and treat it like it was a drop. Just multiply it by 2 cuz you spend the same amount of time going up as you do going down. Unless of course...it's a step up/step down like the Salvation kicker, thats a different story.