Question

The speed of light in a vacuum is 299,792,458 m/s. Which gives this number in three significant digits? 299,000,000. m/s 2.99 x 10-8 m/s 3.00 x 103 m/s 3.00 x 108 m/s

Answer 1

Answer: $2.99(10)^{-8} m/s$

Explanation:

When a number is written in scientific notation (representing the number using powers of base ten) it is expressed so that it contains a digit in the place of the units and all other digits after the decimal point, multiplied by the respective exponent.  

Then, the significant figures (or significant digits) will be the digits that are before the power of ten.  

Now, in the case of the number 299,792,458 if we want to write it with three significant digits, we have to write it in scientific notation as:

$2.99(10)^{-8}$

Answer 2

Answer:

$3.00 \times 10^8 m/s$

Explanation:

during rounding off into given number of significant digits we need to take care of the rounding off

so here we know that speed of light given as

v = 299,792,458 m/s

so when we need to convert it into 3 significant digit then we have to take care of rounding off while converting into 3 digits

since after 3 digits in this given number the next number is 7 so we have to round up the given number

so it would be

$3.00 \times 10^8 m/s$