Jamie used a microscope to measure the diameter of a hair. she found tha the diameter of the hair was 0.000072 meter. how is this number written in scientific notation?

Question

7.2 x 10^-5
7.2 x 10^-6
7.2 x 10^5
7.2 x 10^6

Answer 1

The diameter of the hair is 0.000072 meters. To convert this number into scientific notation, we move the decimal point to the right until we have a number between 1 and 10.

Moving the decimal 5 places to the right gives us:

\[ 7.2 \]

Since we moved the decimal 5 places to the right, we represent this as:

\[ 7.2 \times 10^{-5} \]

Therefore, the correct answer is:

7.2 x 10^-5.