Posted by KD on .
Few question about astronomy:
1.how many centimetres is equivalent to a lightnanosecond
2. How long is an astronomical unit (AU) in lightminutes (1min, i.e., the distance that light travels in a vacuum in one minute)?
Please show the calculation if there is any
Thanks

Astronomy 
bobpursley,
1. speedlight*time= distance
3E8m/s*1E2cm/m*1E9sec=3E1 or 30 cm
2. speedlight*time=distance
3E8m/s*60sec= ? 
Astronomy 
drwls,
2. Sunlight reaches Earth in 8.3 minutes. The EarthSun distance is therefore 8.3 lightminutes.
One way to get the answer is to divide the EarthSun distance by the distance travelled by light in one minute, using the same units.