Suppose the Sun is 1.52669 × 108
km from
Earth.
The speed of light is 2.99792 × 108 m/s.
How long does it take for its light to reach
us?
Answer in units of min
The speed of light in a certain material is 1.3 × 108 m/s. Express the speed of light in (a) feet per nanosecond (ft/ns) and (b) millimeters per picosecond (mm/ps).
To find out how long it takes for light from the Sun to reach Earth, we can divide the distance between the two by the speed of light.
First, let's convert the distance from kilometers to meters. We can do this by multiplying the given distance by 1000 since there are 1000 meters in one kilometer.
Distance from the Sun to Earth = 1.52669 × 10^8 km × 1000 = 1.52669 × 10^11 m
Now, we can divide the distance by the speed of light to find the time it takes for light to reach us.
Time = Distance / Speed of light
Time = (1.52669 × 10^11 m) / (2.99792 × 10^8 m/s)
Calculating this, we find:
Time ≈ 509.4 seconds
However, the question asks for the answer in minutes. To convert seconds to minutes, we divide the number of seconds by 60.
Time = 509.4 seconds / 60 ≈ 8.49 minutes
Therefore, it takes approximately 8.49 minutes for light from the Sun to reach Earth.