The relative velocity of a body `A` with respect to a body `B` is the time rate at which body `A` changes its position with respect to body `B`.
a)If `V_A` and `V_B` are the velocities of `A` and `B` moving in opposite directions,what is the relative velocity of `A` with respect to `B`?
b)Two trains along the same straight rails are moving with constant velocity of `60km/h` and `30km/h` towards each other.If at time `t=0`,the distance between them is `90km`,find the time when they collide.
c)The velocity time graph of two bodies `A` and `B` make angles of `30°` and `60°` with the time axis,what is the ratio of their acceleration?