Answer:
Hello There!
It is Speed.
Because in the question it is said that at which speed car is travelling.
Speed is a scalar quantity.
If it is velocity then first know this that it is a vector quantity.
It must include both magnitude and direction.
If it is velocity then it would be 40 mph east or west or north or south.
<h2>I hope it is helpful to you...</h2><h3>Cheers!_____________</h3>