If a car is moving towards an object and you get the rate of change to be -30 mph, I know that you don't say that the speed of the car is negative, it just means that the distance between the car and the object is decreasing. But, can you call that rate of change a vector? My question arises because if the car was speeding away from the object, the rate of change would be positive, so direction plays a role here.
Or does the sign of the rate of change just works as a description of increasing or decreasing?