Question

A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?

Answer 1

The average speed for a round trip where a car travels from A to B at 40 mph and returns at 60 mph is calculated by dividing the total distance by the total time. Assuming the distance from A to B is D miles, the average speed for the trip is found to be 48 mph.

Step-by-step explanation:

To calculate the average speed for a round trip, we must consider the total distance traveled and the total time taken for the trip, not just the average of the two speeds (40 mph and 60 mph).

Let's assume the distance from A to B is D miles. The time taken to travel from A to B at 40 mph is D/40 hours. The time taken to return from B to A at 60 mph is D/60 hours. The total distance traveled during the round trip is 2D (D miles each way).

The total time for the round trip is the sum of the time taken for each leg of the trip:

Total time = Time from A to B + Time from B to A
= D/40 + D/60
= (3D + 2D) / 120
= 5D/120
= D/24 hours

The average speed for the round trip is the total distance divided by the total time:

Average Speed = Total Distance / Total Time
= 2D / (D/24)
= 2D * (24/D)
= 48 mph

Hence, the average speed for the round trip is 48 mph.

Answer 2

Average speed of round trip is 48 mph

Step-by-step explanation:

Let the distance from A to B be s.

A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph.

`\texttt{Time taken to travel from A to B = }(s)/(40)\\\\\texttt{Time taken to travel from B to A = }(s)/(60)\\\\\texttt{Total time = }(s)/(40)+(s)/(60)\\\\\texttt{Total time = }(60s+40s)/(40* 60)\\\\\texttt{Total time = }(100s)/(2400)\\\\\texttt{Total time = }(s)/(24)`

Total distance traveled = 2s

Total distance traveled = Average speed x Total time

`2s=\texttt{Average speed}* (s)/(24)\\\\\texttt{Average speed = }48mph`

Average speed of round trip is 48 mph