Determine the velocity of car A with respect to car B

Explanation:

There are generally two cases, the first when vehicles ( cars) are going in the same direction and the second is when they are going in the opposite direction, ie. to meet each other.

This is defined by the so-called classical law of velocity summation.

First situation:

Cars are going in the same direction and suppose the speed of the car A is greater than the speed of the car B.

Va > Vb

We simplify this situation by assuming that car B stands and car A moves away from them at a speed equal to their difference

V = Va - Vb

Second situation:

Cars are going in the opposite direction, ie. to meet each other.

It doesn't matter whose speed is higher

We simplify this situation by assuming that car B stands and car A is moving toward car B at a speed equal to their sum or car A stands and car B is moving toward car A at a speed equal to their sum

V = Va + Vb

God is with you!!!

it is the second option.

come closer and become far apart and become steam/gas