the width of a human hair is about 1×10⁻⁴ meter wide. the width of mechanical pencil lead is about 7×10⁻⁴…
the width of a human hair is about 1×10⁻⁴ meter wide. the width of mechanical pencil lead is about 7×10⁻⁴ meter wide. about how many pieces of hair would it take to match the width of a piece of mechanical pencil lead?
Answer
Explanation:
Step1: Identify the widths
Width of human - hair: $1\times10^{- 4}$ meter, width of mechanical - pencil lead: $7\times10^{-4}$ meter.
Step2: Set up the division
We need to find out how many times the width of a human - hair fits into the width of a mechanical - pencil lead. So we divide the width of the mechanical - pencil lead by the width of the human - hair. The formula is $\frac{7\times10^{-4}}{1\times10^{-4}}$.
Step3: Simplify the expression
When dividing numbers in scientific notation with the same power of 10, we divide the coefficients. $\frac{7}{1}=7$ and $\frac{10^{-4}}{10^{-4}} = 10^{-4-(-4)}=10^{0}=1$. So $\frac{7\times10^{-4}}{1\times10^{-4}}=7$.
Answer:
7