One light-hour is the distance that light travels in an hour.How far is this,in kilometers? (Recall that the speed of light is 300,000 km/s. )
A)300,000 km
B)18 million km
C)100 million km
D)1.08 billion km
E)9.46 trillion km

Question

Quizplus · Accepted Answer

One light-hour is equal to the distance that light travels in one hour, which can be calculated by multiplying the speed of light (300,000 km/s) by the number of seconds in one hour (3600 seconds). 
Therefore, the distance of one light-hour can be calculated as:
300,000 km/s x 3600 s = 1,080,000,000 km 
This corresponds with choice D, 1.08 billion km.

One Light-Hour Is the Distance That Light Travels in an Hour.How