A car travels 0.90 km at an average speed of 84.8 km/h and then 0.97 km at an average speed of 41.6 km/h. What is the car's average speed during the 1.87 km interval?
average speed = (distance travelled)/time
= (0.90 + 0.97)/[.90/84.8 + 0.97/41.6]
= 1.87 /(0.010613 + 0.023317)
= 1.87 / 0.03393
= 55.1 miles/hr
answer is same but concept could be more clear
To find the average speed, we need to divide the total distance traveled by the total time taken.
First, let's calculate the time taken for each segment of the journey.
For the first segment:
Distance = 0.90 km,
Speed = 84.8 km/h,
Time = Distance / Speed = 0.90 km / 84.8 km/h
For the second segment:
Distance = 0.97 km,
Speed = 41.6 km/h,
Time = Distance / Speed = 0.97 km / 41.6 km/h
Next, we'll calculate the total time taken for the entire journey.
Total Time Taken = Time for the first segment + Time for the second segment
Now that we have the total time taken, we can find the average speed.
Average Speed = Total Distance / Total Time Taken
Using the given values, let's calculate the average speed.
Time for the first segment:
Time = 0.90 km / 84.8 km/h = 0.0106 hours
Time for the second segment:
Time = 0.97 km / 41.6 km/h = 0.0233 hours
Total Time Taken = 0.0106 hours + 0.0233 hours = 0.0339 hours
Now, let's calculate the average speed:
Average Speed = (0.90 km + 0.97 km) / 0.0339 hours
Average Speed = 1.87 km / 0.0339 hours
Average Speed ≈ 55.16 km/h
Therefore, the car's average speed during the 1.87 km interval is approximately 55.16 km/h.