Roughly, it takes light less than 0.000000003 of a second to travel a one-meter distance. Express this number in the form of a×10^n where 1 ≤ a < 10 and is a one-digit number. (1 point)

Question

3×10^−8


3×10^−9


3×10^8


3×10^9

Answer 1

To express the number \(0.000000003\) in the form \(a \times 10^n\), we can rewrite it as follows:

1. Move the decimal point to the right to get a number between 1 and 10. Here, we can move it 9 places to the right: \[ 0.000000003 = 3 \times 10^{-9} \]

In this form, \(a = 3\) and \(n = -9\).

Thus, the correct expression is:

\[ \boxed{3 \times 10^{-9}} \]