Question

a train starts from a station with acceleration 0.2 m/s2 on a straight track and then comes to rest after attaining maximum speed on another station due to retardation 0.4m/s2. if total time spent is half an hour, then distance between two stations is {neglect length of train}

1. 216 km

2. 512 km

3. 728 km

4. 1296 km

Answer 1

If A is the acceleration of the train and B is the retardation of the train, then the total distance travelled is given by

 [(AB) / (A+B)]. (T^2/2)

Here A = 0.2m/s^2 and B = 0.4m/s^2 and

T = 1/2 hr = 1800 sec

Therefore x= [(0.2) (0.4)/0.2+0.4)]x1800x1800/2

= 216000m

= 216km

Hence the correct answer is 216km

Answer 2

Hope it's understandable..