a woman jogs for 2km at 8km/h and then walks for 2km at 6km/h. What is her average speed for the entire trip?
speed = distance/time, so
(2+2)/(2/8 + 2/6) = 48/7 km/h
time at first speed = 2/8 hrs
= 1/4 hrs
time at 2nd speed = 2/6 hrs
total distance = 4 km
total time = 1/4 + 1/3 = 7/12 hrs
avg speed = 4/(7/12) km/h
= 48/7 km/h or appr 6.86 km/h
To find the average speed for the entire trip, we need to calculate the total distance covered and the total time taken.
1. Distance covered during jogging: 2km
2. Speed during jogging: 8km/h
3. Time taken during jogging: Distance / Speed = 2km / 8km/h = 0.25 hours (15 minutes)
4. Distance covered during walking: 2km
5. Speed during walking: 6km/h
6. Time taken during walking: Distance / Speed = 2km / 6km/h = 0.33 hours (20 minutes)
To find the total distance covered, we add the distance covered during jogging and walking: 2km + 2km = 4km
To find the total time taken, we add the time taken during jogging and walking: 0.25 hours + 0.33 hours = 0.58 hours (35 minutes)
Finally, the average speed for the entire trip can be calculated as the total distance divided by the total time: Average speed = Total distance / Total time = 4km / 0.58 hours ≈ 6.9 km/h
Therefore, her average speed for the entire trip is approximately 6.9 km/h.
To find the average speed of the entire trip, we need to calculate the total distance and the total time taken.
In this case, the woman jogs for 2 km at a speed of 8 km/h, which takes her:
Time = Distance / Speed = 2 km / 8 km/h = 0.25 hours.
Then, she walks for 2 km at a speed of 6 km/h, which takes her:
Time = Distance / Speed = 2 km / 6 km/h = 0.33 hours.
To calculate the total distance, we add the distances of both the jogging and walking parts:
Total Distance = 2 km + 2 km = 4 km.
To calculate the total time, we add the times for jogging and walking:
Total Time = 0.25 hours + 0.33 hours = 0.58 hours.
Finally, to find the average speed, we divide the total distance by the total time:
Average Speed = Total Distance / Total Time = 4 km / 0.58 hours ≈ 6.90 km/h.
Therefore, the woman's average speed for the entire trip is approximately 6.90 km/h.