Question

Mention the various precautions that you must keep in mind while talking measurements of the length of a object

Answer 1

If you are measuring lengths with a metre stick, you are not going to get much accuracy, but there are things you can do.

Don’t start at the end of the stick. They tend to get bashed up. Instead, start at 10cm or any convenient spot.Make sure you look straight down to align the starting point with the markings on the stick. Otherwise parallax errors creep in.Do not try holding the stick and then moving your head to look straight down at the ending point. It is very hard not to move the stick. Best of all is to lay it down and not touch it.If you are measuring a short object that comes in a string of objects, measure as many as you can at once, then divide by the number of them. This divides the measurement errors as well.If you are traveling on a fast train, airplane, or starship, measure side to side rather than in the direction of motion. I understand that the Lorentz-Fitzgerald contraction will shrink both object and scale at the same rate, but who wants to take a chance?