A railway carriage of mass 9000kg moving with a speed of `36kmh^(-1)` collides with a stationary carriage of the same mass. After the collision, the two get coupled and move together. What is this common speed ? What type of collision is this?

Explanation

To solve the problem step by step, we will use the principle of conservation of momentum and analyze the type of collision based on kinetic energy before and after the collision.

### Step 1: Understand the Problem
We have two railway carriages, each with a mass of 9000 kg. One is moving at a speed of 36 km/h, and the other is stationary. After the collision, they couple together and move with a common speed. We need to find this common speed and determine the type of collision.

### Step 2: Convert Speed from km/h to m/s
The speed of the moving carriage is given as 36 km/h. We need to convert this speed into meters per second (m/s) for our calculations.

...