- #1

- 29

- 0

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