Question

An inch is defined to be 2.54 cm. Which of the following statements is true?

(A) 2.54 cm is an exact number
(B) 2.54 cm is a measured number
(C) 2.54 cm is an inexact number
(D) In a calculation where the speed of a worm crawling 1.785 in per 1000 min is converted to cm/min the final answer should only have 3 significant figured because 2.54 only has 3 significant figures
(E) 2.54 is measured but it is really 2540000000

Answer 1

The correct statement is that 2.54 cm is an exact number. The other options are incorrect.

Step-by-step explanation:

In the given statement, 2.54 cm is defined to be 1 inch. This means that both sides of the conversion factor are exact numbers. Therefore, the correct statement is that 2.54 cm is an exact number (Option A).

Option B (2.54 cm is a measured number) is incorrect because the conversion factor is defined and not obtained through measurement or estimation.

Option C (2.54 cm is an inexact number) is also incorrect because both sides of the conversion factor are exact.

Option D (In a calculation involving the conversion of speed from inches to centimeters, the final answer should have 3 significant figures because 2.54 only has 3 significant figures) is not applicable because the provided information in the question does not involve any calculations with the speed of a worm.

Option E (2.54 cm is measured but it is really 2540000000) is also incorrect because 2.54 cm is defined to be 1 inch and is not a measurement value that represents 2540000000.