Question

A star is measured to be 18.9 light years from Earth. What is the correct answer in the calculation shown below? (Consider both significant digits and scientific notation.)

Answer 1

Answer:

$78.79 \times 10^{12} km$

Explanation:

We have been using light-years to specify their distance for the most space objects. one  light-year is the total distance travel by the light in one year and  6 trillion miles (9.65 trillion km) is a light-year. That means $6 *10^{12}$ km is one light year

as we know that one light year equal to $9.46\times 10^{12}$

therefore for 18.9 light year will be

$= 9.46\times 10^{12} \times 18.9 = 178.79 \times 10^{12} km$