Posts
123
Joined
5/14/2015
Location
Wausau, WI
US
duckonquack
6/3/2016 6:19am
6/3/2016 6:19am
Edited Date/Time
6/5/2016 9:04pm
So I have to do a physics problem that applies to real life so i chose ronnie renners gold medal run from 2012. I have to find his acceleration and for that I need the distance between where he starts and where he leaves the jump. Does anyone have any idea how bigs that distance is? I have searched the internet and can not find anything about it. I would imagine it is like 20 feet but im not solid on that. I know this is a weird question but this is a last resort for me so if anyone has any idea please post it!
I believe it's 25 feet? It used to be 35 the first step up event, then they set a standard takeoff length of 25. Could be wrong, like someone else said, just make it up and do the math correctly.
The Shop
Ye olde "distance = rate X time "formula?
I'm assuming you're trying to figure out how fast he would have to accelerate up to the lip in order to reach his takeoff speed of Vinitial that corresponds to his height D? Then you should be able to just set Vfinal equal to 0 and plug in a = -32.2 ft/s^2. I'm willing to guess that the run-up is probably about 20-30 feet maybe, and then you'd just have to factor in the arc length of the jump itself. I think you're alright just making an educated guess, I doubt it's going to be absolutely critical that you get the distance exactly right, especially if you aren't considering how far forward he jumps or what his exact takeoff angle is.
Go easy on me if this is off a little, it's been a couple years since I did a problem like this last.
Remember the jump ramp angles upward to nearly 90 degrees vertical from the horizontal. The motorcycle will accelerate at a certain rate until it begins climbing the ramp. At that point bike and rider will experience an increasing reduction in acceleration until it reaches -9.8m/s^2 at perfectly vertical.
Also, in reality the acceleration of the motorcycle on flat ground itself would not be linear, thanks to the torque curve of the engine.
Hopefully you can provide a simpler "net acceleration" solution to the prof. and you'll be fine. (Or do all the math and blow everyone's mind!!!!)
Stopped in to duckonquacks class. He's hard at work as you can see:
Post a reply to: moto x step up physics problem help