Calculating Light Year and Time Travel
Let's solve the question in two parts as requested.
(a) To show the distance light travels in one year, known as a light year, we need to multiply the speed of light by the number of seconds in a year.
Speed of light = 3.00 x 10^8 metres per second
Seconds per minute = 60
Minutes per hour = 60
Hours per day = 24
Days per year ≈ 365.25 (accounting for leap years)
Seconds in a year = Seconds per minute x Minutes per hour x Hours per day x Days per year
Seconds in a year = 60 x 60 x 24 x 365.25
Seconds in a year ≈ 31,557,600
Distance light travels in one year = Speed of light x Seconds in a year
Distance ≈ 3.00 x 10^8 m/s x 3.15576 x 10^7 s
Distance ≈ 9.46728 x 10^15 metres
This value is approximately 9.5 x 10^15 metres, as required.
(b) To find the time, in seconds, that light takes to travel 180 metres, we use the formula:
Speed = Distance / Time
Time = Distance / Speed
Given distance = 180 metres
Speed of light = 3.00 x 10^8 metres per second
Time = 180 m / (3.00 x 10^8 m/s)
Time = 1.80 x 10^2 m / 3.00 x 10^8 m/s
Time = 0.60 x 10^(-6) seconds
Time = 6.00 x 10^(-7) seconds
Therefore, the light takes 6.00 x 10^(-7) seconds to travel 180 metres. This answer is already in standard form.
