To calculate the distance covered by the train before coming to rest, we need to find the time it takes for the train to stop and then use that time to calculate the distance traveled.
Given: Initial velocity (u) = 72 km/hr Final velocity (v) = 0 km/hr (when the train comes to rest) Acceleration (a) = -0.5 m/s²
First, let's convert the initial velocity from km/hr to m/s: u = 72 km/hr = (72 * 1000) / 3600 m/s = 20 m/s
We can use the following kinematic equation to calculate the time taken for the train to stop: v = u + at
Rearranging the equation, we get: t = (v - u) / a
Substituting the values: t = (0 - 20) / (-0.5) t = 40 seconds
Now, we can calculate the distance covered using the equation of motion: s = ut + (1/2)at²
Substituting the values: s = 20 * 40 + (1/2) * (-0.5) * (40)² s = 800 - 400 s = 400 meters
Therefore, the distance covered by the train before coming to rest is 400 meters.