Final answer:
A lighthour is calculated by multiplying the distance of a lightminute, which is 1.8×107 km, by the number of minutes in an hour, resulting in a lighthour being 1.08×109 kilometers.
Step-by-step explanation:
A lightminute is a unit of distance that light travels in one minute. Given that a lightminute is 1.8×107 kilometers long, we can calculate the distance of a lighthour by multiplying this figure by the number of minutes in an hour, which is 60.
To find the distance that light travels in an hour, we have: 1.8×107 km/lightminute × 60 minutes/hour = 1.08×109 km/lighthour.
Therefore, a lighthour is 1.08×109 kilometers.