# 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

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) $\dfrac{v_{1}+v_{2}}{a}$