Question

Suppose you are calculating the volume of an object using the following formula: 2.45 cm × 3.2 cm × 4.078 cm. What is the volume of the object expressed to the correct number of significant digits?

Answer 1

Volume of the object=2.45 cm × 3.2 cm × 4.078 cm

=31.97 cm³

=32 cm³

Correct number of significant figures allows the answer to be 32 cm³.

As while doing multiplication and division, the answer must have the same number of significant figures as in the term with the fewest number of significant figures. So we round off the number to get correct significant numbers that is 32 cm³.

Answer 2

Volume of an object =
`2.45 cm* 3.2 cm* 4.078 cm`

Now, according to significant figures rules of multiplication, the least number of the significant figures present in the question, determines the least number of significant figures in the solution.

Here, 3.2 cm has the least number of significant figures i.e. 2; therefore, the answer must be in only two significant figures.

Thus, volume of an object =
`31.97152 cm^(3)`

Round off the value of volume into two significant figures only, we get

Volume of an object =
`32 cm^(3)` (two significant figures)