Answer :
Certainly! Let's break down the solution step-by-step to find the average speed of the car during its journey from City A to City B.
1. Total Distance:
The total distance travelled by the car from City A to City B is 80 km.
2. First Part of the Journey:
- Distance: The car travels the first 60 km.
- Speed: The car’s speed during this part of the journey is 60 km/h.
- Time: To find the time taken for this part of the journey, we use the formula:
[tex]\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{60 \text{ km}}{60 \text{ km/h}} = 1 \text{ hour} \][/tex]
3. Second Part of the Journey:
- Distance: The car travels the remaining 20 km (which is the total distance 80 km minus the first part's distance 60 km).
- Speed: The car’s speed during this part of the journey is 80 km/h.
- Time: To find the time taken for this part of the journey, we use the formula:
[tex]\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{20 \text{ km}}{80 \text{ km/h}} = 0.25 \text{ hours} \][/tex]
4. Total Time for the Journey:
The total time taken for the entire journey is the sum of the time taken for both parts:
[tex]\[ \text{Total Time} = 1 \text{ hour} + 0.25 \text{ hours} = 1.25 \text{ hours} \][/tex]
5. Average Speed:
The average speed for the entire journey can be calculated using the total distance and the total time:
[tex]\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{80 \text{ km}}{1.25 \text{ hours}} = 64 \text{ km/h} \][/tex]
Conclusion:
The car’s average speed for the journey from City A to City B, considering the given distances and speeds, is [tex]\( 64 \)[/tex] km/h.
1. Total Distance:
The total distance travelled by the car from City A to City B is 80 km.
2. First Part of the Journey:
- Distance: The car travels the first 60 km.
- Speed: The car’s speed during this part of the journey is 60 km/h.
- Time: To find the time taken for this part of the journey, we use the formula:
[tex]\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{60 \text{ km}}{60 \text{ km/h}} = 1 \text{ hour} \][/tex]
3. Second Part of the Journey:
- Distance: The car travels the remaining 20 km (which is the total distance 80 km minus the first part's distance 60 km).
- Speed: The car’s speed during this part of the journey is 80 km/h.
- Time: To find the time taken for this part of the journey, we use the formula:
[tex]\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{20 \text{ km}}{80 \text{ km/h}} = 0.25 \text{ hours} \][/tex]
4. Total Time for the Journey:
The total time taken for the entire journey is the sum of the time taken for both parts:
[tex]\[ \text{Total Time} = 1 \text{ hour} + 0.25 \text{ hours} = 1.25 \text{ hours} \][/tex]
5. Average Speed:
The average speed for the entire journey can be calculated using the total distance and the total time:
[tex]\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{80 \text{ km}}{1.25 \text{ hours}} = 64 \text{ km/h} \][/tex]
Conclusion:
The car’s average speed for the journey from City A to City B, considering the given distances and speeds, is [tex]\( 64 \)[/tex] km/h.
