Answer:
81.14 Earth days.
Explanation:
Step 1
The formula to solve this question is given as
Speed = Distance / Time
In the question, we are given the following values
Distance of the planet = 74,000,000 km
Average Speed of the planet = 38,000 km/h.
Average Speed = Distance / Time
38,000 km/h = 74,000,000 km/ Time
Cross Multiply
38,000 km/h × Time = 74,000,000 km
Divide both sides by 38,000 km/h
Time(hours) = 74,000,000 km /38,000 km/h
Time(hours) = 1947.3684211 hours
This means the circular orbit of the planet around the star takes 1947.3684211 hours.
Step 2
In the question, we were asked to find how many Earth days it takes.
Hence, it is known that
24 hours = 1 (Earth) day
1947.3684211 hours = x days
We would cross Multiply
24 hours × x days = 1947.3684211 hours.
Divide both sides by 24 hours
x days = 1947.3684211 hours ÷ 24 hours
x days = 81.140350879 Earth days.
Therefore, the number of Earth days it takes the planet to orbit the star to 2 significant figures =
81.14 Earth days.