Question

The speed of light is now defined to be 2.99792458 10 m/s (a) Express the speed of light to three significant figures m/s (b) Express the speed of light to five significant figures m/s (c) Express the speed of light to seven significant figures

Answer 1

Answer:

a) 3.00×10⁸ m/s

b) 2.9979×10⁸ m/s

c) 2.997925×10⁸ m/s

Explanation:

299792458 m/s is the speed of light

Let us write this in scientific notation first

2.99792458×10⁸ m/s

a) In three significant figures

We need to round the number to the hundredths place

3.00×10⁸ m/s

b) In five significant figures

We need to round the number to the ten thousandths place

2.9979×10⁸ m/s

c) In seven significant figures

We need to round the number to the millionths place

2.997925×10⁸ m/s