Question : The driver of an express train moving with a velocity 𝑣1 finds that a goods train is moving with a velocity 𝑣2 in the same direction on the same track. He applies the brakes and produces a retardation 𝑎. The minimum time required to avoid collision is
(A) \dfrac{v_{1}-v_{2}}{a}
(B) \dfrac{v_{1}}{a}
(C) \dfrac{v_{1}}{a}
(D) \dfrac{v_{1}+v_{2}}{a}
Answer : option (A)
Solution :
