Question

Calculate the number of light years in a petametre. (1 petametre = \[{10^{15}}m\]).

Answer 1

Hint: 1 Peta metre = ${10^{15}}$ metre. We will use this conversion formula of distance to calculate the number of light years contained in 1 Peta metre.
Also, 1 light year = 9.46 $ \times $ \[{10^{15}}m\].

Complete step-by-step answer:
1 Light year is a unit of distance whose value is 9.46 $ \times $ \[{10^{15}}m\] .
The amount of Light years contained in 1 petametre can be calculated as follows:
Number of light years in 1 petametre = $\dfrac{{{{10}^{15}}}}{{9.46 \times {{10}^{15}}}}$
Number of light years in 1 petametre = 0.1

Hence, 0.1 light year distance is contained in 1 petametre.

Additional Information: On the scale of the universe, measuring distances in miles or kilometers is not feasible at all. We can’t use kilometers as the unit for measuring distance in space as we do for measuring the simple distance such as time taken to reach from here to the school, astronomers measure the distances of stars in the time it takes for light to travel to us. For example, the nearest star to our sun, Proxima Centauri, is 4.2 light-years away similarly the second nearest star which is called Alpha century is 4.36 light years away.

Note: The light-year is a unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometres ( $9.46 \times {10^{12}}$ km). The light-year is most often used when expressing distances to stars and other distances on a galactic scale.