To find the speed of the car when it returns from town B to town A, we first need to analyze the given information.
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The car travels from A to B at a speed of 60 km/h for 2 hours.
- Distance from A to B = Speed × Time = 60 km/h × 2 hours = 120 km.
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The average speed for the round trip (from A to B and back to A) is 50 km/h.
To find the total time taken for the round trip, we can use the formula for average speed:
\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]
The total distance for the round trip from A to B and back to A is:
\[ \text{Total Distance} = 120 \text{ km} + 120 \text{ km} = 240 \text{ km} \]
Using the average speed, we can calculate the total time for the round trip:
\[ 50 \text{ km/h} = \frac{240 \text{ km}}{\text{Total Time}} \]
Rearranging this gives us:
\[ \text{Total Time} = \frac{240 \text{ km}}{50 \text{ km/h}} = 4.8 \text{ hours} \]
- We already know the time taken to go from A to B is 2 hours. Therefore, the time taken to return from B to A is:
\[ \text{Time from B to A} = \text{Total Time} - \text{Time from A to B} = 4.8 \text{ hours} - 2 \text{ hours} = 2.8 \text{ hours} \]
- Now, we can find the speed of the car when traveling from B to A. The distance from B to A is still 120 km. Thus, the speed from B to A can be calculated as follows:
\[ \text{Speed from B to A} = \frac{\text{Distance}}{\text{Time}} = \frac{120 \text{ km}}{2.8 \text{ hours}} \approx 42.857 \text{ km/h} \]
So, the speed of the car when it moves from B back to A is approximately 42.86 km/h.
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