Hint: In order to know the law applying to the working of a balloon car, we shall first look into the working of a balloon car. How this thing works, its mechanism and all the forces acting on it must be taken under consideration. Further, we must have prior knowledge of Newton’s laws of motion to rectify whether it applies on this balloon car or not.
Complete answer: A balloon car is an object where there is a small toy car with wheels for smooth motion and usually a platform. At the back of the toy car, an inflated balloon is tied and its mouth is kept together by a temporary support to prevent it from getting deflated. When the toy car is to be set in motion, the temporarily held opening of the balloon is set free. The gas filled inside the balloon comes out rushing with an immense force which sets the small car in motion. Hence, we see that the force of thrust exerted by the escaping gas initiates the motion of the car. Newton’s third law of motion says that every action has an equal and opposite reaction. This means that every body on which some force is acting in some direction is also exerting force of equal magnitude but in the exactly opposite direction. Here, we have the force by the escaping gas acting as the action and the motion of the car in turn as the reaction. Therefore, the car uses the thrust applied on to set off its motion.
Note: We can observe Newton’s third law of motion being applied all around us during our day-to-day activities. The most common example is the one of us walking on the floor. As we walk, our foot exerts force on the floor. The floor in return applies an equal and opposite force on us, namely the force of friction on us. If this force of friction was not present, then it would not be possible for us to walk either.