Question

The speed of light in a vacuum is 3.00 ´ 108 meters/second (m/s). There are 100 centimeters (cm) in 1 meter (m). How much time is needed for light to travel 1.00 cm in a vacuum

Answer 1

$$
\large{
1~cm=.01m\\
\cfrac{1}{3(10)^8~m/s} \times .01~m\\
=(1/3)\times10^{-2}10^{-8}~s\\
=(1/3)\times10^{-10}
}
$$

Make sense?

Answer 2

no, which one of these would be the answer?
3.33 mc015-1.jpg 10–11 s
3.33 mc015-2.jpg 10–9 s
3.00 mc015-3.jpg 1010 s
3.00 mc015-4.jpg 108 s

Answer 3

Do you know that speed = distance traveled / time taken?
$$
speed=\cfrac{distance}{time}\\
\implies time=\cfrac{distance}{speed}
$$
We know distance is .01 meters and speed is \(3(10)^8 m/s\).

http://www.wolframalpha.com/input/?i=%281%2F3%2910%5E%28-10%29