Question 1031625
my journey to work is at 10mph in heavy traffic, my journey home is at 30mph with no traffic. what is my average speed to work and back?
-----------
Avg of the round trip is
2*10*30/(10 + 30) = 600/40
Avg = 15 mi/hr
-------------------
The formula is similar to parallel resistors and parallel work.
==============
One way distance = d
Avg speed = (d/10 + d/30)/2
You can solve that and get the same answer.
Avg = 40d/600 = d/15
--> Avg = 15 mi/hr