Answer:
The average speed for the whole journey is 44.[tex]\overline 4[/tex] kilometers per hour
Explanation:
The average speed with which the car travels the distance, v₁ = 50 kilometer per hour
The average speed with which the car returns, v₂ = 40 kilometer per hour
Average speed, v = (Total distance, d)/(Total time, t)
Let 'd' represent the distance travelled, we have;
The time it takes the car to travel to the distance = d/50 hours
The time it takes the car to return = d/40 hours
The total time = (d/50 hours + d/40 hours) = d·(40 + 50)/(40 × 50) hours= 9·d/200 hours
The total distance = d kilometers+ d kilometers = 2·d kilometers
The average speed for the whole journey, v = 2·d kilometers/(9·d/200 hours) = 400/9 kilometers per hours = 44.[tex]\overline 4[/tex] kilometer/hour.
