Answer:
1254.16 miles per hour
Step-by-step explanation:
First, we need to calculate the circumference at 30° latitude
Circumference =2πR
Where R = Radius = 3990.5 miles
Circumference =2 * 22/7 * 3990.5 = 25083.143 miles
This is the distance traveled in one revolution
1 rev (according to the question) = 20 hours
Using dimentional analysis,
Linear Speed = Radius (25083.143) / Rev time (20)
Linear Speed = 25083.143 / 20
Linear Speed = 1254.16 miles per hour