A train goes from station a to station b in 2 hours. The distance between stations is 10 km. At what speed must the train make its reverse journey in order to have an average journey speed of 10 km/hr?
Answers
Answer:
The velocity of train during traveling from B to A = u = 15 km/hr.
Step-by-step explanation:
Data:
Distance between the stations = D = 10 km
Average velocity = x = 10 km/hr
Time taken by train to go from Station A to Station B = t = 2 hours = 2 hr
let
The velocity of train during traveling form A to B = v
The velocity of train during traveling form B to A = u
Required:
The velocity of train during travailing form B to A = u = ?
Calculation:
We know that
velocity = v = displacement / time = D / t
Putting values we get
v = (10 / 2 ) km/hr = 5 km/hr.
And
We know that
average velocity = x = ( u + v ) / 2
putting values we get
⇒ 10 = (u + 5) / 2
⇒ 20 = u +5
⇒ u = 15 km/hr
So the velocity of train during traveling from B to A = u = 15 km/hr
Answer:
infinite speed required
Step-by-step explanation:
Distance between stations = 10 km
Total Distance = 10 + 10 = 20 km
Average speed required = 10 km/hr
Time required = 20/10 = 2 hrs
2 hrs are already taken by train
so no time left for reverse journey
so infinite speed required for reverse journey
May by data is wrong in question