A good-quality measuring tape can be off by 0.42 cm over a distance of 28 m. What is its percent uncertainty? (Express your answer to the correct number of significant figures and proper units.)

0.015%

Explanation:

Data provided in the question:

Length by which the measuring tape can be off, δL = 0.42 cm

Total measured length for which Error of δL is observed, L = 28 m

Now,

we know,

1 m = 100 cm

Thus,

28 m = 28 * 100 = 2800 cm

Percent uncertainty = [δL : L] * 100%

= [0.42 : 2800] * 100%

= 0.015%