Final answer:
The effects of the force are to slow down the car.
Step-by-step explanation:
A force acts when a car brakes while approaching a set of traffic lights. The effects of the force are to slow down the car.
When a car applies the brakes, the force of friction between the tires and the road surface opposes the motion of the car. This friction force acts in the opposite direction to the car's motion, resulting in a deceleration, which slows down the car.
For example, when you press the brake pedal in a car, the brake pads press against the rotating brake discs on both sides of each wheel. This creates friction, which generates a force that acts in the opposite direction to the car's motion, ultimately causing it to slow down.