An express train is running behind a goods train on the same line and in the same direction, their velocities being u1 and u2 (u1 > u2) respectively. When there is a distance x between them, each is seen from the other. At which point it is just possible to avoid a collision f1 is the greatest retardation and f2 is the greatest acceleration which can be produced in the two trains respectively?

MCQs on calculus applications like increasing and decreasing functions, tangents and normals, straight line motion, motion under gravity, calculus applications like maxima and minima, acceleration and velocity.