Let's start by calculating the average velocity for the first leg of the journey.
(a) The average velocity can be calculated using the formula:
Average Velocity = Distance / Time
Firstly, convert the distance travelled from kilometers to meters for more precise calculation so 0.550 kilometers is equal to 550 meters (since 1 kilometer is equal to 1000 meters).
Given,
Distance = 550 meters
Time = 40 seconds
Substituting these values into the above formula, we get:
Average Velocity = 550 meters / 40 seconds = 13.75 m/sec
So, the average velocity for the first leg of the run is 13.75 m/sec.
Now, let's move on to the second part of the question.
(b) To get the average speed for the total trip, we simply use the formula:
Average Speed = Total Distance / Total Time
Again, convert the distance for the return leg from kilometers to meters. The total distance traveled is thus 2*550 = 1100 meters (550 meters for each leg) and the total time is 40 seconds + 45 seconds = 85 seconds.
Substituting these values into the formula gives us:
Average Speed = 1100 meters / 85 seconds ≈ 12.9 m/sec (rounded to one decimal place)
Hence, the average speed for the total trip is 12.9 m/sec.