Question

Are Car Travels certain distance with a speed of 50 kilometre per hour and returns with a speed of 40 kilometre per hour what is the average speed for the whole journey

Best answer branlist and NO LINKS​

Answer 1

The average speed for the whole journey is 44.
`\overline 4` kilometers per hour

Step-by-step 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.
`\overline 4` kilometer/hour.