When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion? -the car slows down
-The car speeds up.
-The car travels at constant speed.
-The car remains at rest.

Assuming rightward is positive, the velocity is positive whenever the car is moving to the right, and the velocity is negative whenever the car is moving to the left. The acceleration points in the same direction as the velocity if the car is speeding up, and in the opposite direction if the car is slowing down.

Explanation:

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

conduction, convection, radiation