Answer:
64 mph
Step-by-step explanation:
Given that:
Speed for the first 3 hours = 52 mph
Average speed for 4 hours = 55 mph
To find:
Speed for the next hour = ?
Solution:
Formula for average speed is given as:
[tex]Average\ Speed = \dfrac{Total\ Distance}{Total \ Time \ Taken}[/tex]
Formula for Distance:
[tex]Distance =Speed \times Time[/tex]
Distance traveled in first 3 hours:
[tex]Distance =52\times 3 = 156\ miles[/tex]
Let the speed for the next hour = u mph
Distance traveled in 1 hour = [tex]u \times 1 = u\ miles[/tex]
Total distance traveled = (156 + u) miles
Total time = 4 hours
Average Speed = 55 mph
Putting the values in formula:
[tex]55 = \dfrac{156+u}{4}\\\Rightarrow 220 = 156+u\\\Rightarrow \bold{u = 64\ mph }[/tex]
So, the answer is: 64 mph
