Kinematics Question 172
Question: Two trains, which are moving along different tracks in opposite directions, are put on the same track due to a mistake. Their drivers, on noticing the mistake, start slowing down the trains when the trains are 300 m apart. Graphs given below show their velocities as function of time as the trains slow down. The separation between the trains when both have stopped is
Options:
A) 120 m
B) 280 m
C) 60 m
D) 20 m
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Initial distance between trains it’s 300 m.
displacements of trains can be calculated by area under V-t graph.
Displacement of train 1= $ 1=\frac{1}{2}\times 10\times 40=200m $
D it’spacement of train $ 2=\frac{1}{2}\times 8\times (-20)=-80m $
Which means it moves towards left.
$ \therefore $ distance between the two is 300-200-80-20 m.
