Final answer:
As a tire gets worn out, the friction becomes greater, not shorter. The tread depth of a tire decreases as it wears out, resulting in a decrease in the contact area between the tire and the road, which leads to a longer braking distance.
Step-by-step explanation:
As a tire gets worn out, the friction becomes greater, not shorter. When a tire is new, it has a higher coefficient of friction, which allows it to provide better grip on the road. However, as the tire wears out, the tread depth decreases, resulting in a decrease in the contact area between the tire and the road. This decreases the friction between the tire and the road, leading to a longer braking distance.