A radar gun records the speed of a projectile to be 120.090 m/s. How many significant digits are present in this measurement?

6

Explanation:

Significant figures:

The given measurement have six significant figures 120.090.

All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

Leading zeros are not consider as a significant figures. e. g. 0.03 in this number only one significant figure present which is 3.

Zero between the non zero digits are consider significant like 104 consist of three significant figures.

The zeros at the right side e. g 2400 are also significant. There are four significant figures are present.

In 120.090 the zero before and after 9 are also significant.