The radius of Earth = 6,400 km, and the spaceship is 3,250 km above the Earth.
So radius of Spaceship's orbit = 6,400 km + 3,250 km = 9,650 km.
The distance covered to complete one orbit would be circumference of the circle with radius 9,650 km.
So, circumference of circle = 2π·r = 2π·(9,650) = 19,300π km
It says it completes one orbit in 4 hours, then its speed = [tex]\frac{19,300\pi }{4} \;kmph =4,825\pi \;kmph \approx 15,158.18 \;kmph[/tex]
So, it travels approximately 15,158.18 kilometers in one hour.
