d1v1n1ty nb
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im posed with the question why an equation may be homogeneous with respect to its units but still be incorrect? i can't think of way to explain this can anyone help me out? Thanx
Why Can an Equation Be Homogeneous but Incorrect?
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Consider a rod with length L1 = 15 cm and another rod with length L2 = 10cm.
Now put the two rods one after the other.
Consider the following formula: the total length of the two rods L = L1 - L2 = 5 cm.
This formula is dimensionally correct, and the answer is wrong.
Another formula:
the total length equals L = L1 L2 / (L1 + L2) = 150 cm^2 / 25 cm = 6 cm
Again, the formula is dimensionally correct, but gives the wrong anwer.
...
Now put the two rods one after the other.
Consider the following formula: the total length of the two rods L = L1 - L2 = 5 cm.
This formula is dimensionally correct, and the answer is wrong.
Another formula:
the total length equals L = L1 L2 / (L1 + L2) = 150 cm^2 / 25 cm = 6 cm
Again, the formula is dimensionally correct, but gives the wrong anwer.
...
d1v1n1ty nb
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Thanx, thts a good way to describe it. Is there any well known common formulae that fits this trend?
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Force is ma = kgm/s2
So imagine we have an object with mass m and length L just sitting there for some period of time t. Then the net force F=m*L/t2 doesn't actually turn out to be 0.
So imagine we have an object with mass m and length L just sitting there for some period of time t. Then the net force F=m*L/t2 doesn't actually turn out to be 0.
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A well-known formula that doesn't work? No...d1v1n1ty nb said:
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d1v1n1ty nb said:
Pick a pile of exam copies of first year students
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Except that it is probable that none of those will be dimensionally correct either!
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HallsofIvy said:
Right !