I had done my experiment but i not get 9.81 for the value of gravity...why?

Question

I had done my experiment but i not get 9.81 for the value of gravity...why?

Answer 1

Whenever you do an experiment, you have to expect some error.  There is an entire field of math dedicated to analyzing and interpreting this error, but for a physicist like you who doesn't capitalize his sentences, it's enough to know that an experiment will almost never give you exactly the right answer.  Depending on how finely tuned your experiment is, your results could differ from theory only slightly or quite a bit.  If you're getting a number that's nowhere near 9.81, though, it means you did something wrong, either in setting up your experiment or interpreting the results.

Answer 2

I agree with the person on top of me.