How do I convert "35.0 yd"35.0 yd to "nm"nm?

1 Answer
Aug 24, 2016

I got 3.20xx10^10 "nm"3.20×1010nm.


You can go about it in more than one way; it depends on which conversion factors you know best. I would recommend that you use the ones you definitely remember.

The general pathway I would approach it is:

cancel"yd" xx cancel"ft"/cancel"yd" xx cancel"in"/cancel"ft" xx cancel"cm"/cancel"in" xx cancel"m"/cancel"cm" xx "nm"/cancel"m"

So, the conversion factors we will use are:

  • "3 ft" in one "yd"
  • "12 in" in one "ft"
  • "2.54 cm" in one "in"
  • One "m" in "100 cm"
  • 10^9 "nm" in one "m"

Therefore, we get:

35.0 cancel"yd" xx (3 cancel"ft")/cancel"yd" xx (12 cancel"in")/cancel"ft" xx (2.54 cancel"cm")/cancel"in"
xx cancel"m"/(100 cancel"cm") xx (10^9"nm")/cancel"m"

= color(blue)(3.20xx10^10 "nm")

You keep three significant figures because all of these conversion factors are exact, and the measurement is known to a specific uncertainty (by default, pm 0.1).

So, your answer has 3 significant figures.