Answer:
Average Velocity = 120 mi/h
Explanation:
First we need to calculate the time taken by Connie to complete first half from Phoenix to flagstaff. So, we use:
s₁ = v₁t₁
where,
s₁ = distance from Phoenix to flagstaff = 180 miles
v₁ = speed of travel from Phoenix to flagstaff = 180 mi/h
t₁ = time taken to travel from Phoenix to flagstaff = ?
Therefore,
180 miles = (180 m/h)t₁
t₁ = 1 h
Now, we calculate the time for the return trip
s₂ = v₂t₂
where,
s₂ = distance from flagstaff to Phoenix = 180 miles
v₂ = speed of travel from flagstaff to Phoenix = 90 mi/h
t₂ = time taken to travel from flagstaff to Phoenix = ?
Therefore,
180 miles = (90 m/h)t₂
t₂ = 2 h
Now, we find total time:
t = t₁ + t₂
t = 1 h + 2 h
t = 3 h
and the total distance was:
s = s₁ +s₂
s = 180 mi + 180 mi
s = 360 mi
So, the average velocity will be:
Average Velocity = s/t
Average Velocity = 360 mi/3 h
<u>Average Velocity = 120 mi/h</u>