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If a person who weighs 180lb jumps up 1 meter high and falls back on the ground with natural velocity, what's the weight in pounds when he hits the ground?It is really hard to say. There is a simple way to calculate this in Physics. But you need to make one big (but reasonable) assumption.
You calculate the energy input as mass (81.65 kg) * height (1m) * gravity (9.8m/s^2) and get about 800 joules.
Now all of that 800 joules must be dissipated in the impact.
800 joules = Force Impact (Newtons) * Distance (Meters)
Let’s say when he lands, his joints and knees bend a little and he decelerates uniformly for about 6″ (15cm)
Force(Newtons) = 800 joules/.15 Meters = 5334 Newtons = 1200 pounds!
Twelve hundred pounds !
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