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Jump trajectory and distance physics formula

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Jump trajectory and distance physics formula
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flag MnM1618
Posted: May 26, 2009 at 22:23 Quote
hay i'v built a big booter its ten feet long and 5'6 high (ill have pic's soon)...its a pirfict artch for launching ... i was wondering iff ennyone knows the formula for distance iff i have velocity im m/s and time in m/s. i was hoping to be able to predict my (almost) exact distance traviling at a given speed.... can ennyone help?Smile
flag dandriller
Posted: May 26, 2009 at 22:32 Quote
Hey...

Post the pics of your injuries after you crash.

EDIT: You're talking to yourself!
flag captainbringdown
Mod
Posted: May 26, 2009 at 22:50 Quote
it doesn't matter how long the ramp is, or the height really. you are going to be on an arc. the more speed, the greater the diameter of the arc. you need the angle of the lip, that will be more helpful for you to determine the distance you can travel. i don't have a formula, there would be one for motion like this, but since the suspension is involved, it wont be perfect. look up pendulums, and think about it inversely. or just hit it.
flag MnM1618
Posted: May 26, 2009 at 22:58 Quote
isaacsx wrote:
it doesn't matter how long the ramp is, or the height really. you are going to be on an arc. the more speed, the greater the diameter of the arc. you need the angle of the lip, that will be more helpful for you to determine the distance you can travel. i don't have a formula, there would be one for motion like this, but since the suspension is involved, it wont be perfect. look up pendulums, and think about it inversely. or just hit it.

thanks ill do that ... um the angle of the lip is 67.5 degres i think
and id be going about 30km/h or 8.34 m/s
flag MnM1618
Posted: May 26, 2009 at 23:00 Quote
MnM1618 wrote:
isaacsx wrote:
it doesn't matter how long the ramp is, or the height really. you are going to be on an arc. the more speed, the greater the diameter of the arc. you need the angle of the lip, that will be more helpful for you to determine the distance you can travel. i don't have a formula, there would be one for motion like this, but since the suspension is involved, it wont be perfect. look up pendulums, and think about it inversely. or just hit it.

thanks ill do that ... um the angle of the lip is 67.5 degres i think
and id be going about 30km/h or 8.34 m/s

and thats gust an average gess on speed rolling in ... it might be more it might be less ill find out soon when i put my spedo into on my bike
flag lafalot
Posted: May 26, 2009 at 23:34 Quote
MnM1618 wrote:
To calculate the range of a projectile, including you on a bike jumping a ramp, it's like this. The range of the projectile is directly proportional to the square of your velocity. In other words, D=kVsquared..

Let's say you're jumping, oh a 5'6 feet ramp lol at 30km. Using this equation, 5'6=k(30)squared, or 5'6=k1225. Dividing both sides by 1225 gives you .0045714=k.

To calculate how far you'll jump at 35km, it's D=k35squared, or D=(.0045714)1225. The answer is that you'd fly APPROXIMATELY 5.599965 feet at 3O-35km.

I don't know where you got that formula D=kV^2, but that is certainly not what you need. You also equated D = height of ramp, and then followed with D = distance. wtf? If you have a highschool physics textbook, look up "projectile motion" for the proper equation. You need to account for the angle of take off, and calculate both the vertical and horizontal velocity vectors separately to find out where you would ideally land without air friction.
flag signorvince2
Posted: May 26, 2009 at 23:44 Quote
MnM1618 wrote:
To calculate the range of a projectile, including you on a bike jumping a ramp, it's like this. The range of the projectile is directly proportional to the square of your velocity. In other words, D=kVsquared..

Let's say you're jumping, oh a 5'6 feet ramp lol at 30km. Using this equation, 5'6=k(30)squared, or 5'6=k1225. Dividing both sides by 1225 gives you .0045714=k.

To calculate how far you'll jump at 35km, it's D=k35squared, or D=(.0045714)1225. The answer is that you'd fly APPROXIMATELY 5.599965 feet at 3O-35km.

Why are you mixing your units?
flag mehow1993
Posted: May 26, 2009 at 23:48 Quote
heres an idea, instead of using math just think how far you want to go and build a landing there
flag united-bmx-1994
Posted: May 27, 2009 at 1:43 Quote
ahaha +1


edit- quoted on mehow1993
flag brodoyouevenbike
Posted: May 27, 2009 at 1:52 Quote
photo

2823357


lol if you hit a ramp at 24 Kph thats what would hapopend depending on lip angle.

tup

the darker numbers are feet, and the thinner ones are metres
flag Internetbiker
Posted: May 27, 2009 at 2:00 Quote
MnM1618 wrote:
To calculate the range of a projectile, including you on a bike jumping a ramp, it's like this. The range of the projectile is directly proportional to the square of your velocity. In other words, D=kVsquared..

Let's say you're jumping, oh a 5'6 feet ramp lol at 30km. Using this equation, 5'6=k(30)squared, or 5'6=k1225. Dividing both sides by 1225 gives you .0045714=k.

To calculate how far you'll jump at 35km, it's D=k35squared, or D=(.0045714)1225. The answer is that you'd fly APPROXIMATELY 5.599965 feet at 3O-35km.

That doesn't seem right to me, surely you need to factor in gravity at some point, also you need to convert all your units in to SI units to stand some kind of chance of getting the right answer.
flag wakiisapuddinghead
Posted: May 27, 2009 at 2:15 Quote
wind resistance???

there is a lot more to it than a few calculations

throw some dirt to check wind

throw a rock to check for trajectory and possible speed esitmate

and always go a little faster than your gut is telling you to

and if it doesn't feel right then don't go for it

and fear is good as it keeps your limits in check

Wittgenstein theorized that we can never know the truth and how often have the numbers been right but the real picture was quite different!
flag aaronlampman
Posted: May 27, 2009 at 21:41 Quote
ok lets see this booter!!!!
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