two trains starting at the same time having length 200 m each are moving in same direction.If the speed of each train is 30 kilometre per hour and 35 km per hour respectively find when they will cross each other.
The answer is 4 minutes 48 second.
Prove the answer.
Answers
Answer:
I think answer should be 2.4 min
Step-by-step explanation:
method 1
there are two methods which are as follows
Define x:
Let the duration be x
Define the trains:
Let Train A be the train that traveled at 30km/h
And Train B be the train that traveled 35 km/h
Express the distance traveled by train A in term of x
Distance = Speed x Time
Distance = 30x
Express the distance traveled by train B in term of x
Distance = Speed x Time
Distance = 35x
The length of the each train is 200 m.
Therefore, for the train to completely cross each other, Train B (the faster train) will have to be 200 ahead of train A.
Convert 200 m to km
200m = 0.2 km
solve x:
35x - 30x = 0.2 km
5x = 0.2
x = 0.04 h or 2.4 mins
Answer: The train will crossed each other in 2.4 mins.
method 2
in image using concept of relative motion ....
If helpful then please mark it as brainliest
Step-by-step explanation:
I think , answer is 4 min. 48 sec.
So, Let's begin...
Let the time be 't' when they will cross each other.
For The Trains,
Let train A that travelled at 30 km/hr.
And train B that travelled at 35 km/hr.
Now, the distance travelled by train A in terms of 't'.
Distance = Speed × Time
Distance = 30t
Similarly, the distance travelled by train B in terms of 't'.
Distance = Speed × Time
Distance = 35t
Since, the length of the each train is 200 m.
Therefore, for the trains to completely cross each other. Train B (more speed) will have to travel 400 m ahead of train B.
Thus, Distance in Km = 400/1000 km
= 0.4 km
As we know, when trains moving in same direction, their speeds are subtracted.
35t - 30t = 0.4
5t = 0.4
t = 0.4 / 5
't' in sec. = 4/50 × 3600
= 288 sec.
= 4 min. 48 sec.
Hence, They will take 4 min. 48 sec. to cross each other.