Answer
4
Work Step by Step
Apply the rules on page 162 of the book to find the significant digits (the accuracy) of the measurement 20.00 m
We use rule #1: all non-zero digits are significant. Thus "2" is significant.
We also use rule #4: all zeros to the right of a significant digit and decimal point are significant; that is, we have here 3 zeros, which are significant.
Thus, there are 4 significant digits.
