Talk:Trajectory of a projectile

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wow

Thanks to whoever made a cleaner version of my free body diagram. Looks great, except that those x and y indicies on v and F(sub a) are subscripts, not exponents. I'd really be grateful if you could just touch it up for me. Thanks. --Random nick 05:16, 5 February 2006 (UTC)


The free body diagram is excellent, but it does not print properly. It shows up as a black square when printed. I have seen this problem with images captured from powerpoint as jpg's before. If a .tif format is used, this problem goes away. Thanks, Eve65.165.72.203 19:00, 24 July 2006 (UTC)

Contents

[edit] This is not an encyclopedia article

It's a high school problem... solved... (No trolling intended... just being clear) --euyyn 22:54, 25 July 2006 (UTC)

[edit] I believe the air resistance calculation is incorrect:

The force due to air resistance is not directly proportional to the velocity of the object, it is directly proportional to the square of the velocity of the object. Imageine the object moving through air at v, the object is colliding with n air molecule per unit of time t. Each collision will exert an average amount of imulse per molecule i. The force of drag on the object will be ni/t=drag. If the speed is increased to 2v, the molecules strike the object twice as hard, imparting approximately 2 time the impulse 2i per impact. At the same time, twice the number of molecules 2n are hitting the object in the same amount of time t. (2i)(2n/s)=four times the drag. Unfortunately, this means that someone who is better than me at WikiMath formatting will have to redo the differential equations. 69.76.242.48 06:56, 13 October 2006 (UTC)

The matter must have to be with fluids. We should maybe consider viscosity to understand it (the air just around the proyectile moves along the surface, not just colliding and "bouncing"). --euyyn 04:46, 19 December 2006 (UTC)
Drag is proportional to v at low velocities and v^2 at high velocities. --Gellender 06:21, 20 December 2006 (UTC)
Yes, in fact it is only proportional to v for very slow bodies, very small bodies, or for a big viscosity (which isn't the case with air). But I wont fix it since I believe this article doesn't belong in Wikipedia. Maybe in Wikiversity; undergraduate first course of Physics or first course of Differential Equations. For further info see Reynolds number and Viscous flow. --euyyn 21:00, 1 February 2007 (UTC)
The example in the end is not well-suited. For the given data drag due to viscosity (proportional to v) should be around 0.001N and due to pressure around 22N (proportional to v^2). I guess both regimes could be considered, however surely more concisely. Wrwrwr 20:26, 31 August 2007 (UTC)

[edit] Wasted my time on finding a formula for drawing the trajectory on Cartesian coordinates

m=\frac{h+d}{d^2}+(\theta\,-1)\frac{1}{d}

f(x) = -mx^2+\theta\,x+h

h = launch height
 d = flight distance
 θ = launch angle (slope)
 m = coefficient

You'll get a pretty trajectory (without air resistance in mind, of course) of your favorite projectile on a graphical calculator. Is this awesome, y/n? Well, at least this kind of math is fun. --nlitement [talk] 01:16, 23 September 2007 (UTC)

[edit] Equations - Expert

I added on the expert tag in place of the cleanup tag. It doesn't require cleanup in terms of manual of style, but it does have a series of equations that to a person unfamiliar with topic (e.g. me) doesn't seem to make much sense and/or offers no explanation as to what is occurring. They seem to be just thrown in together. Barkeep Chat | $ 13:30, 10 June 2008 (UTC)