relative velocity in one dimension concepts ,shortcuts and questions of jee,neet,cbse etc

relative velocity in one dimension concepts ,shortcuts and questions
1.A passenger is at a distance ‘d’ from a bus,
when the bus begins to move with a constant acceleration a. Then find the minimum
constant velocity with which the passenger
should run towards the bus so as to catch is?
2.Two trains, each travelling with a speed of
1
37.5kmh
, are approaching each other on
the same straight track. A bird that can fly at
60kmph flies off from one train when they
are 90 km apart and heads directly for the
other train. On reaching the other train, it
flies back to the first and so on. Total
distance covered by the bird before trains
collide is?
3.On a two-lane road, car A is travelling with
a speed of 36 kmph. Two cars B and C
approach car A in opposite directions with
speed of 54 kmph each. At a certain instant,
when the distance AB is equal to AC, both
being 1 km, B decides to overtake A before
C does. What minimum acceleration of car
B is required to avoid an accident?