Two cars A and B are running at velocities of 60km per hour and 45 km per hour. What is the relative velocity of car A with respect to car B, if both are moving eastwards?

Relative velocity is the vector difference between velocities of two bodies. If two bodies are moving in the same direction then relative velocity is given by their difference If two bodies are moving in the opposite direction we sum up their velocities. It means that one moving in the opposite direction is negative velocity and the other one is positive velocity. Positive and negative sign indicates the direction. Since, both are moving Eastwards A = +60 km /h B = +45 km / h Relative speed = 60 - 45 = 15 km / h