The discussion revolves around a physics problem involving the dynamics of a car exiting a ditch, specifically focusing on the motion of the car's wheels and the forces at play during this transition. Participants are exploring concepts related to angular momentum, trajectory equations, and the effects of the car's center of mass on its motion.
The discussion is ongoing, with participants providing corrections and clarifications to previous posts. There is a sense of progress as some participants feel closer to understanding the dynamics involved, although multiple interpretations and questions remain. Guidance has been offered regarding the equations of motion, but no consensus has been reached on the overall model of the situation.
Participants note that the original question may have been poorly phrased, leading to misunderstandings. There is also mention of the physical setup being described rather than a standard exercise, which may affect the clarity of the discussion. Constraints related to the geometry of the dip and the car's wheelbase are under consideration.
So you confirm that the 3rd element in the wheels coordinate expressions is neessary. I'll reflect a bit more on this.haruspex said:Ah, yes, I see my mistake. In post #92 I omitted an "h+" at the start of the formula. It's in my spreadsheet, but I missed it.
##V_0z## should be ##=ω_0 L##.alex33 said:Before starting the simulation of phase 2 (free fall), I ask you to confirm the starting data:
##V_0x = V = 2,52 m/s ## (Chord length / 18 frames ...I think it is the most reliable data)
##V_0z = \frac {1}{2}V* \tan(α)##
##ω_0 = \frac {1}{2L}V* \tan(α) - (\frac {3g*L}{h^2+4L^2}*4/24)##
##X_0c= \frac {chord-length}{2}-L##
##Z_0c = \frac {(ω_0 + \frac {1}{2L}V* \tan(α))}{2} * L * 4/24##
##θ_0 = \frac {V * \tan(α)}{2L}*4/24##
Thanks
The first model is the absorption of sharp edges of the tires, then the spring mass shock model. Otherwise this buggycar will drive anyone buggy without more assumptions being defined or become just a wooden car with no suspension and solid rubber tires with an extremely rough ride.alex33 said:Thanks Tony !
we went from theory to numbers just to verify the first proposed solution to the problem, with respect to a real event, but identifying the correct physical model is always the main objective of the question I asked in this thread. So thank you for your comments on which I and the other friends who have made themselves available will reflect for sure.
Dear Haruspex, do you check the values I send you? Please take a look at last calculations we shared. Thanksharuspex said:##V_0z## should be ##=ω_0 L##.
##Z_0c ## needs "h+", as discussed.
For ##θ_0## I use the average rotation rate during del t:
##(\frac {V * \tan(α)}{2L}+ω_0)/2*4/24##
I will do, but did not get a chance today.alex33 said:Dear Haruspex, do you check the values I send you? Please take a look at last calculations we shared. Thanks