Line c is at rest . line a is going in a positive direction . line b is going in a negative direction . line d is negative too
Due to attraction ... of opposite charges
Their relative speed is the sum of 60 and 40 or 100km/hr. They will travel the 150km in 1.5 hrs. When two object approach each other, the closing speed is just the sum of the speeds, therefore, the closing speed is your case is 100kph. So they will meet in 1.5 hours.
It would be either A or C if its still moving and not stopping
