Units of energy
Units of energy
(OP)
Hey, hopefully someone can help me with this. My problem is this, i have calculated the kinetic impact energy of a 272 tonne structure travelling at 0.05m/s to be 341 J.
I am then using conservation of energy to define that strain energy = kinetic energy. Using a spring rate (k) of 50000 N/mm I should output a deflection of 0.117mm. However, Mathcad is outputting 3.7mm.
The only reasons I can find for this Mathcad is using 341000 J (341kJ). My energy is defiantly defined as joules & I have repeated the calculation in a new worksheet; with the same results.
Has anyone else experienced this or give me any explanation?
I am then using conservation of energy to define that strain energy = kinetic energy. Using a spring rate (k) of 50000 N/mm I should output a deflection of 0.117mm. However, Mathcad is outputting 3.7mm.
The only reasons I can find for this Mathcad is using 341000 J (341kJ). My energy is defiantly defined as joules & I have repeated the calculation in a new worksheet; with the same results.
Has anyone else experienced this or give me any explanation?





RE: Units of energy
RE: Units of energy
David
RE: Units of energy
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RE: Units of energy
David
RE: Units of energy
The OP wasn't using SI. The units of J are N.m, not N/m and certainly not N/mm.
But if you use consistent units it doesn't matter whether you use SI or not, or even whether you use Excel.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/