Question

Ramesh and Sandeep are two very close friends who study in classes IX and X respectively. One day Ramesh and Sandeep had to go to a neighbouring twon on their bicycles for some work. They had to cross a railway line on the way to the neighbouring town. when Ramesh and Sandeep were going in the afternoon, the railway crossing barrier was open, so they did not have to wait for going across it. Their work in the neighbouring town kept Ramesh and Sandeep bust till late in the evening. On their way back home, when Ramesh and Sandeep reached the same railway crossing, it was quite dark in the night and the railway crossing barrier was down (or closed) indicating that some train was expected to pass through soon. Ramesh was in a hurry to go back home. Ramesh told Sandeep that since he could not hear the sound of approaching train, so they did not know when the train would pass through the crosing and barrier would open. He suggested that instead of keeping on waiting, they should cross the railway tracks by going below the closed barrier by tilting their bicycles and lowering their heads. Sandeep did not agree with Ramesh. Sandeep said that they would not cross the railway tracks as long as the barrier was closed. Suddenly, Ramesh slipped through the barrier and put his ear on the railway track. Sandeep pulled him away from the railway track quickly. As soon as Ramesh was pulled away from the railway track, a super-fast train passed through the same track in the darkness of night without blowing any horn. Sandeep was very angry with Ramesh and scolded him for the risk he had taken. After the train passed through the crossing, the barrier was opened by railway staff. Ramesh and Sandeep then crossed the railway track alongwith their bicycles and reached home safely.
(a) How many times more is the speed of sound in railway track then the speed of sound in air?
(b) Why did Sandeep not allow Ramesh to cross the closed barrier of railway crossing?
(c) Why did Ramesh put his ear to the railway track?
(d) Why did Sandeep pull Ramesh away from the railway track?
(e) What values are displayed by Sandeep in this episode?

Answer 1

(a) Railway track is made of steel. The speed of sound in railway track (made of steel) is about 15 times more than the speed of sound in air.
(b) Sandeep did not allow Ramesh to pass through the closed barrier of railway crossing because it is very risky to do so. A closed barrier indicates that a train could pass through his crossing any time. And if a person is crossing the railway tracks at the time when a train is approaching very fast, it can lead to a train accident in which the person can get injured seriously or even killed (more especially in the darkness of neight).
(c) Ramesh put his ear to the railway track to hear the sound of coming train through the railway track made of steel and get an idea of the distance of the incoming train (because the speed of sound in railway track made of steel is very high as compared to the speed of sound in air).
(d) Sandeep pulled Ramesh away from the railway track quickly because he did not want Ramesh to be involved in a train accident.
(e) The various values displayed by Sandeep in this episode are (i) Awareness that most of the train accidents are fatal (which cause death) (i) Desire to prevent train accident (by not passing through)closed railway crossing barrier), and (iii) Concern for the safety of his friend (in pulling him away from railway track).