Final answer:
The distance from a star 300 light years away from Earth is calculated by multiplying the number of light-years by the distance light travels in one year, resulting in a distance of 2.84019×10^15 km.
Step-by-step explanation:
To calculate the distance from a star that is 300 light years away from Earth, we must first understand what a light-year is. A light-year is the distance light travels in one year, and since the speed of light is 3×105 km/s, we can calculate a light-year as follows:
Distance of one light-year = Speed of light (km/s) × Number of seconds in one year.
To find the number of seconds in one year:
1 year = 365.25 days (accounting for leap years),
1 day = 24 hours,
1 hour = 60 minutes,
1 minute = 60 seconds.
Thus,
1 year = 365.25 × 24 × 60 × 60 = 31,557,600 seconds.
Distance of one light-year = 3×105 km/s × 31,557,600 s = 9.4673×1012 km.
The distance to the star in light years × Distance of one light-year = 300 × 9.4673×1012 km = 2.84019×1015 km.
The distance from the star to Earth is 2.84019×1015 km, written in standard form.