Units conversion for impact test - ft.lb to Joules
Units conversion for impact test - ft.lb to Joules
(OP)
I've got a US spec which asks for a 100ft.lb impact test done by a drop tube. I almost can't bare to ask this, but what is the height and weight for that test?
If it's really a 1 lb weight from 100 feet, or 100lb from 1 foot, that's (please check!) a 5kg weight from 2.8m or 137 Joules.
The reason I ask is a European spec asks for 20J impact which I'm confident we can meet, so I'm really hoping I've miscalculated this 100ft.lb
If it's really a 1 lb weight from 100 feet, or 100lb from 1 foot, that's (please check!) a 5kg weight from 2.8m or 137 Joules.
The reason I ask is a European spec asks for 20J impact which I'm confident we can meet, so I'm really hoping I've miscalculated this 100ft.lb





RE: Units conversion for impact test - ft.lb to Joules
RE: Units conversion for impact test - ft.lb to Joules
I was really hoping to be wrong by a factor of 10, something to do with lb weight and lb force....
RE: Units conversion for impact test - ft.lb to Joules
another day in paradise, or is paradise one day closer ?
RE: Units conversion for impact test - ft.lb to Joules
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist
RE: Units conversion for impact test - ft.lb to Joules
zdas, I've got two different specs for a similar product, one says 100ft.lb and the other says 20J. By my (and RobyengIT's) calculations they are very, very different. I was looking for someone to say I had made a mistake and that 100ft.lb was around 20 Joules
RE: Units conversion for impact test - ft.lb to Joules
Your phrasing makes me nervous. You can generate 100ft.lb energy by lifting a 100lb weight 1ft, or by lifting a 1lb weight 100ft. When the weight arrives back at the ground, the 100ft.lb will be in the form of kinetic energy, less air resistance.
100ft.lb×4.45N/lb×.3048m/ft=136N.m, as noted above.
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JHG
RE: Units conversion for impact test - ft.lb to Joules
But thank you for your help!