One car is travelling along a straight road at 60km/h while another car is travelling around a circular track at 60km/h. Are they travelling with the same velocity? If not, why?
Velocity is dependent on direction, they are travelling at the same speed (scalar) but the velocities (vector) are different because they are bound by direction.
Yes, but for only one instant out of each revolution of the car on the circular track
Assume that car on the straight road is going East. As the car on the circular track goes around the circle, there will be an instant when that car is also facing East; and at that instant the velocity vectors of both cars will be pointing East.
At that instant, you could say that "both cars have identical ' instantaneous velocity '." (If you could say that fast enough for it all to be during that instant. Sorry, just a joke.)
You could say, at any moment, that both cars have the same speed since speed is not a vector -- therefore direction is not a factor with their speeds. You could also say that the magnitude of the velocities of both cars are equal.
I hope this helps,