Question 465940
how can i calculate average speed
when a plane is flying from one city to another and is 550 miles per hour and is 430 miles per hour on the return flight.
---------------
Average speed for a round trip is similar to parallel resistors, but times 2.
Avg speed = 2*550*430/(550 + 430)
= 473000/980
=~ 482.65 mph
----------
It's always less than the average of the 2 speeds, because more time is spent moving at the lower speed (unless they're the same speed).