- #1
James_fl
- 29
- 0
Hi, I have a question regarding significant figure.
One rule when multiplying measured quantity is that the final answer needs to use the least number of significant digits provided in the question.
Now.. if v = 17 m /s and t= 0.8 s. What is d?
d = v * t
d = 17 m / s * 0.8 s
d = 13.6 m
Now, v has two significant digits. But what about t? Can we consider t to have two significant digits instead of one?
So, should I leave the answer the way it is (3 significant digits), round it up to 14 m (2 significant digits), or round it down to 10 m (could be considered as 1 or 2 significant digits)?
My dillema is if t is considered as having 1 significant digit and I do need to round the answer down to 10 m, wouldn't it be much less precise than 13.6? Why should I make it less precise, wouldn't a more precise answer better than the unprecise one?
Also, if I do need to round it down to 10 m, how should I write down my final answer? Just plain 10 m or 1*10^1 m ?
Thanks very much,
James
One rule when multiplying measured quantity is that the final answer needs to use the least number of significant digits provided in the question.
Now.. if v = 17 m /s and t= 0.8 s. What is d?
d = v * t
d = 17 m / s * 0.8 s
d = 13.6 m
Now, v has two significant digits. But what about t? Can we consider t to have two significant digits instead of one?
So, should I leave the answer the way it is (3 significant digits), round it up to 14 m (2 significant digits), or round it down to 10 m (could be considered as 1 or 2 significant digits)?
My dillema is if t is considered as having 1 significant digit and I do need to round the answer down to 10 m, wouldn't it be much less precise than 13.6? Why should I make it less precise, wouldn't a more precise answer better than the unprecise one?
Also, if I do need to round it down to 10 m, how should I write down my final answer? Just plain 10 m or 1*10^1 m ?
Thanks very much,
James