Question

The distance between two station is 500 kmA train goes from one station to the other with the speed of 50 km/hr and return from a speed of 25 km/hr what is is the avrage speed of the train during the journey​

Answer 1

Question based on:

Kinematics. Here, we have the distance covered in one trip and the respective speeds. So, we can find the total distance travelled and the time. And then calculating the average speed.

GiveN:

• Distance between two station is 500 km
• Speed in first trip = 50 km/hr
• Speed in return trip = 25 km/hr

Step-by-step Explanation:

Average speed is given by Total distance covered / Total time taken in the journey. Here,

Total distance travelled

= 500 × 2 km

= 1000 km

Time taken in trip 1:

= Distance / Speed

= 500 km / 50 km/hr

= 10 hr

Time taken in return trip:

= Distance / Speed

= 500 km / 25 km/hr

= 20 hr

Total time taken = 30 hr

Average speed of the journey:

= Total distance / Total time taken

= 1000 km / 30 hr

= 100/3 km/hr

= 33.34 km/hr (approx.$)$

Hence,

• The average speed of the train during the journey is 33.34 km/hr. And we are done! :D

Answer 2

Solution :

As per the given data,

• Distance between 2 stations(d) = 500 km

Total distance covered(D)

⇒ D = 2d

⇒ D = 500 + 500 = 1000 km

• s' = 50 km / hr
• s" = 25 km / hr

we know that ,

$\implies s = d / t$

here ,

• s = speed
• d = distance
• t = time

On rearranging ,

⇒ t ' = d  / s '

⇒ t ' = 500 / 50

⇒ t ' = 10 hr

Similarly ,

⇒ t " = d / s"

⇒ t" = 500 / 25

⇒ t " = 20 hr

Total time (t)

⇒ t = t ' + t"

⇒ t = 10 + 20

⇒ t = 30 hr

--------------------------------

⇒ Average speed = total distance / total time

⇒ Average speed = D / t

⇒ Average speed = 1000 / 30

⇒ Average speed =  33.3 km / hr

The average speed of the train is 33.3 km / hr .