Question

Train travelling at 90km/hr crosses goods train at 50km/hr in opposite direction completely in 50 sec.How long it takes train to overtake same goods train,if travellling in same direction?

Answer 1

Ans:-1.25m/s*s

Explanation:

U=90km/hr=25m/s

V=50km/hr=13.8m/s

Time=50s

Acceleration=v-u/t

Il =25-13m/s/50s

Il. =0.224m/s*s

Answer 2

Answer:

The correct answer is 175 seconds.

Explanation:

This can be solved by taking into consideration the relative speed.

Let the total distance to be covered be the sum of the length of both the trains

So, Distance = Speed* Time ( Relative speed= 90+50 = 140 km/hr)

Converting it to m/s = 140 *(5/18) = 38.89 m/s

Now, finding the total length= 38.89 *50 = 1944.5 m

Hence, the time required to overtake the goods train when travelling in the same direction = Distance/Relative Speed

Since the direction is same the relative speed will be the subtraction of both the speeds.

Relative speed = 90-50= 40 km/hr

Changing into m/s = 40*5/18 = 11.11 m/s

Time = 1944.5 /11.11 = 175 seconds.