Question

a car travel A certain distance with a speed of 50 km per hour and return with a speed of 40 km per hour calculate the average speed of whole journey

Answer 1

Let the distance covered be x.

Speed of the car during the on ward journey = 50 km/h

Time taken during onward journey $(t_1)$ = $\frac{x}{50}$ hr

Speed of the car during return journey = 40  km/hr

Time taken during return journey $(t_2)$ = $\frac{x}{40}$

Total time taken = $(t_1 + t_2)$

Total distance covered = x + x = 2x

Average speed = $\frac{2x}{\frac{x}{50} +\frac{x}{40}}$

Average speed = $\frac{2 \times 200}{4 + 5}$

Average speed = 44.44 km/h

Hence, the average speed for entire journey is 44.44 km/h