1 Topic by P1

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This maybe a question beyond the scope of the software itself, but I thought I'd ask as there are plenty of smart people on this forum.

I'm going to try to "crudely" calculate Differential Specific Mechanical Energy - or the dissipation of mechanical energy from pre-recorded TV footage of mountain bike World Cups.

The challenges of camera angles and lense distortion etc.. maybe too great to overcome, but some of you on here maybe able to help overcome those issues?

The inspiration for the concept comes from this Alpine Skiing paper - https://www.academia.edu/62737191/Diffe … ine_skiing

the equation is below
diff(emech) = ∆emech/(−∆z) = −∆(v2/2)/∆z − g

So I need to try and calculate COM position and subsequent velocity of CoM from that.

I have the altitude data already recorded manually at these events, so the only data (I think) I need from the video is velocity.

I sense a near impossible task, but please let me know what you think

2 Reply by joan

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Not for center of mass per se, but since it's mountain bike maybe from the wheels? Measuring rotation per minute and knowing the radius?
Would have to test this on controlled footage first to get some error bars.

3 Reply by P1

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Thank you! I have already done (well tried) to calculate wheel speeds before. Sadly due to independent braking and acceleration of wheels it's not a useful method for a proxy of CoM velocity.

Thanks for the reply though