Question

a train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 18 seconds. what is the length of the platform in meters?

Answer 1

$<b><i>$Length of the platform

= speed of train × extra time taken to cross the platform.

= 72 kmph ×12 seconds

Since unit is different so we will make it with same unit.

So ,Now we will Convert 72 Kmph into m/sec

As we know

$1 kmph = \frac{5}{18} m/s \:$

$∴ 72 \: \: kmph \: \: = \frac{5}{18} \times 72 \: \\ \\ = 20 m/sec$

Therefore, length of the platform

= 20 m/s × 12 sec

= 240 meters.

Thanks

Have a colossal day ahead

Be Brainly

 

Answer 2

Answer:

The required length of the platform = 240 meters

Step-by-step explanation:

Speed of the train is given to be = 72 km/hr.

Changing this speed into meters per second

⇒ Speed of the train = 20 m/s.

Now, Time taken to cross the Platform = 30 seconds.

Time taken to cross the man = 18 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 = 20 × 18

                                     = 360 meter

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

⇒ 360 + Length of platform = 20 × 30

⇒ 360 + Length of platform = 600

⇒ Length of platform = 600 - 360

                                    = 240 meters

Thus, The required length of the platform = 240 meters