Explanation :Uncertainty in measurements and calculations means difference between actual and measured data. We can say that all measurements have some degree of uncertainty. It can be of two types-1. Systematic error (because of error in measuring instrument) 2. Random error (human errors such as- delay in starting, delay in stopping).
Systematic errors are consistent in magnitude and direction so they can be easily removed by additive or proportional corrections while random errors vary in magnitude and direction and can not be easily removed.
Uncertainty means that your result may be very random, so you can't trust the first or second or so observation, making several samples critical for accuracy. <span />
