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Picture of Trajectory Modeling

This is an example of how to model the simple trajectory of a potato discharged from a potato cannon. To do this you need to have the gravitational constant, velocity of the projectile as it leaves the barrel, and the angle between the barrel and the ground.

Step 1: Finding Velocity

Picture of Finding Velocity
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My first step is to find the velocity. I used the method of finding the distanced traveled per frames. Knowing the frame rate of the camera, the velocity can be calculated. In my case I calculated, as seen in the video, the velocity to be 60ft/s since it traveled 5ft in 5 frames while being filmed at 60 frames/s.

5ft * (1/5 frames) * 60 frames/s = 60ft/s

 
jakeframe1 year ago

You could take this experiment a step further by measuring the real world trajectory and using that data to calculate the air resistance.

showden (author)  jakeframe1 year ago

I actually started out doing that and creating my own drag coefficient model. But it got into differential equations with conflicting x and y equations. I think I messed up with the integration so I simplified it and didn't worry about the drag, haha. But I had it narrowed down to two equations and two unknowns after putting in the initial conditions, but something was off.

Migs1 year ago

Can you post your spreadsheets?

showden (author)  Migs1 year ago

Yes I can; should be up now.

Migs showden1 year ago

Thanks!