Respuesta :
it will take 1 hour to catch up to train a but if the question means from as soon as train a leaves, it is 3 hours.
The time taken by train B to cover the distance of 56 km when the train at the station is in 1 hour.
What is kinematics?
It is the study of the motion of a body without considering mass. And the reason behind them is neglected.
Train A leaves a station traveling at 28 km/hr.
Two hours later train B leaves the same station traveling in the same direction at 84 km/hr.
The distance traveled by the train A in two hours will be
[tex]\rm D_A=28 \times 2 = 56 km[/tex]
Then the distance between the trains when train B is at the station is 56 km.
Then the relative speed of the train will be
[tex]\rm V_{BA} =84 - 28 = 56 \ km/hr[/tex]
Then the time taken by train B to cover the distance of 56 km is in 1 hour.
More about the kinematics link is given below.
https://brainly.com/question/25638908
