Human hair grows at a rate of about 6.849×10−4

cm per hour to 2.329×10−2
cm per hour. The rate depends on gender, genetics, age, and health. Find the difference between the high end and the low end of the range. Express your answer in scientific notation. Do not round your answer.

1 answer

To find the difference between the high end and the low end of the range of human hair growth rates:

  1. Identify the growth rates:

    • Low end: \(6.849 \times 10^{-4}\) cm per hour
    • High end: \(2.329 \times 10^{-2}\) cm per hour
  2. Convert both numbers to the same exponent for easy subtraction. The low end can be rewritten:

    \[ 6.849 \times 10^{-4} = 0.0006849 \text{ cm per hour} \]

    And the high end can be expressed as:

    \[ 2.329 \times 10^{-2} = 0.02329 \text{ cm per hour} \]

  3. Now, we can convert the low end to match the exponent of the high end:

    \[ 6.849 \times 10^{-4} = 0.0006849 = 0.00006849 \times 10^{-2} = 6.849 \times 10^{-4} \times \frac{10^{2}}{10^{2}} = 684.9 \times 10^{-6} \]

  4. Now, subtract the two values:

    \[ 2.329 \times 10^{-2} - 6.849 \times 10^{-4} \]

    Converting \(2.329 \times 10^{-2}\) into a comparable format:

    \[ 2.329 \times 10^{-2} = 23.29 \times 10^{-3} \]

    Now, we rewrite the low end in terms of the same exponent:

    • \(6.849 \times 10^{-4} = 0.6849 \times 10^{-3}\)
  5. Now we can subtract:

    \[ (23.29 \times 10^{-3}) - (0.6849 \times 10^{-3}) = (23.29 - 0.6849) \times 10^{-3} = 22.6051 \times 10^{-3} \]

  6. Now, convert it back into scientific notation:

    \[ 22.6051 \times 10^{-3} = 2.26051 \times 10^{-2} \]

So the difference between the high end and the low end of the hair growth rate is:

\[ \boxed{2.26051 \times 10^{-2}} \text{ cm per hour} \]