# Thread: Finding Absolute Uncertainty From Relative Uncertainty

1. ## Finding Absolute Uncertainty From Relative Uncertainty

Good morning, I have a problem in front of me that is asking for the absolute uncertainty of an area (A rectangular board is measured to have a width, w, of 2.00 ± 0.02 m and length, l, of 10.80 ± 0.04 m). I have the correct answer for the relative uncertainty and the area, so I'd assume since I have those, I could use them to solve for the absolute uncertainty, but it's coming back saying my answer is wrong, and I have no idea how to solve it.

Area = 21.6 m^2
Relative uncertainty = 0.01

Thanks.

2. Originally Posted by sim
Good morning, I have a problem in front of me that is asking for the absolute uncertainty of an area (A rectangular board is measured to have a width, w, of 2.00 ± 0.02 m and length, l, of 10.80 ± 0.04 m). I have the correct answer for the relative uncertainty and the area, so I'd assume since I have those, I could use them to solve for the absolute uncertainty, but it's coming back saying my answer is wrong, and I have no idea how to solve it.

Area = 21.6 m^2
Relative uncertainty = 0.01

Thanks.
How do you get that relative uncertainty?

What do you think the absolute uncertainty is?

Think about when you round and the effects of premature rounding.

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