How is Average Speed Calculated for a Two-Part Journey?

AI Thread Summary
To calculate the average speed for a two-part journey, the total distance and total time must be considered. In this case, a car travels 19 km at 91 km/h and 61 km at 65 km/h. The time for the first segment is approximately 0.208 hours, and for the second segment, it is about 0.938 hours. The overall average speed is calculated by dividing the total distance (80 km) by the total time (1.146 hours), resulting in an average speed of approximately 69.81 km/h. This method effectively determines the average speed for multi-segment journeys.
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Homework Statement


A car is driven 19 km at an average speed of 91 km/h and after that 61 km at an
average speed of 65 km/h.

Homework Equations


What was the average speed of the whoIe joumey?

The Attempt at a Solution


t1=19/91 = 0.208 h
t2=61/65 = 0.938 h

average speed = (19+61)/(0.208+0.938)
average speed = 69.808 km/h
 
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This looks fine.
 
looks ok! :smile:
 
its correct!
 

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