Quote:
Originally Posted by Grug556
Some cursed engineer will come around shortly and critique my crude calculations . Anyhow say you were driving 30mph and hit the stump you would with a 5000lb vehicle have roughly 150 000lbs of impacting force on the cross member. Sizeable impact force.
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it's been a while since I was in school. but we can use the equations for kinetic energy and work and solve for force. some rearranging implies:
horizontal impact force applied to the cross member is F = (1/2 * mass * velocity^2) / distance
mass = 5000lbs or about 2268 kg
velocity = 30 mph or about 13 metres per second
distance to stop = about 2 inches it looks like is indented on that cross member or about 0.0508 metres
F = 3.77 million Newtons. or about 850 thousand lb feet of force. now obviously angle, road terrain, any trim pieces that slowed impact etc etc . and if you actually broke through the stump as well significantly changes the results. but I believe the equations above are the right ones to use here. literally if you hit that stump going horizontally at 30mph, and it literally stopped your rig dead in its tracks and only dented the support a couple inches then that is A LOT of force transferred to the vehicle. I suspect you tore that stump right apart lessening the impact force on your truck, or that is one strong-ass stump man! or you were going slower than you thought!