Answer: 4.97 / 0.00833 = 597.77 miles per hour.
Explanation:
To find the average speed of the plane in miles per hour, we first need to convert the distance the plane travels from kilometers to miles. One mile is equal to 1.609 kilometers, so 8 kilometers is equal to 8 / 1.609 = 4.97 miles.
Next, we need to convert the time the plane takes to travel this distance from seconds to hours. There are 3600 seconds in an hour, so 30 seconds is equal to 30 / 3600 = 0.00833 hours.
To find the average speed of the plane in miles per hour, we can now divide the distance the plane travels by the time it takes to travel that distance. This gives us 4.97 / 0.00833 = 597.77 miles per hour.