Question

A train travelling at 36kmph crosses a platform in 20 seconds and a man standing on the platform in 10 seconds. what is the length of the platform in

Answer 1

Hello Dear.

Here is the answer---→

Speed of the Train = 36 km/hr.
= 36 × 5/18  [Changing into m/s]
= 2 × 5
= 10 m/s.

Given ⇒ 
Time taken to cross the Platform = 20 seconds.
Time taken to cross the man = 10 seconds.

∵ Speed of the Train = Length of the Train/Time to cross the Man
∴ Length of the Train = Speed of the Train × Time to cross the Man.
   = 10 × 10
   = 100 m.

Now,
Sum of the Length of Platform and train = Speed of the Train × Time taken by the Train to cross the Platform.
= 10 × 20
= 200 m.

∵  Length of the Train + Length of the Platform = 200
∴  100 + Length of the Platform = 200
∴ Length of the Platform = 200 - 100
   = 100 m.


∴ Length of the Platform is 100 m.



Hope it helps.

Answer 2

Answer:

The required length of the platform = 100 meters

Step-by-step explanation:

Speed of the train is given to be = 36 km/hr.

Changing this speed into meters per second

⇒ Speed of the train = 10 m/s.

Now, Time taken to cross the Platform = 20 seconds.

Time taken to cross the man = 10 seconds.

Also, Speed of the Train = Length of the Train/Time taken to cross the man

⇒ Length of the Train = Speed of the Train × Time taken to cross the man

⇒ Length of the train = 10 × 10

                                     = 100 meter

Now, Length of the Train + Length of the Platform = Speed of the Train × Time taken by the Train to cross the Platform.

⇒ 100 + Length of platform = 10 × 20

⇒ 100 + Length of platform = 200

⇒ Length of platform = 200 - 100

                                    = 100 meters

Thus, The required length of the platform = 100 meters