Question

Few question about astronomy:

1.how many centimetres is equivalent to a light-nanosecond
2. How long is an astronomical unit (AU) in light-minutes (1min, i.e., the distance that light travels in a vacuum in one minute)?

Please show the calculation if there is any

Thanks

Answer 1

1. speedlight*time= distance
3E8m/s*1E2cm/m*1E-9sec=3E1 or 30 cm

2. speedlight*time=distance
3E8m/s*60sec= ?

Answer 2

2. Sunlight reaches Earth in 8.3 minutes. The Earth-Sun distance is therefore 8.3 light-minutes.

One way to get the answer is to divide the Earth-Sun distance by the distance travelled by light in one minute, using the same units.