Question

please answer fast.if possible send the photo of the solution

Answer 1

let take the velocities as u and v
when they move in opposite direction or say towards each other
8=v+u
v=8-u
when they move in same direction
v-u=4
8-u-u=4
8-2u=4
2u=4
u=2m/s
v=8-2=6m/s
use the concept of relative velocities