Final answer:
Bicycle blowouts can occur on hot days due to the increase in tire pressure, a result of the hot air inside expanding from the heat. The Ideal Gas Law shows the relationship between pressure, volume, and temperature, explaining why hotter temperatures can lead to increased pressure and potential blowouts. The correct option is b) Hot air expands, increasing tire pressure.
Step-by-step explanation:
Leaving a bicycle in the sun on a hot day can cause a blowout because hot air expands, increasing tire pressure. This phenomenon can be explained by the Ideal Gas Law, which illustrates the relationship between pressure, volume, temperature, and the amount of gas.
As the temperature increases, like on a hot day, the air inside the tire expands. If the tire is already fully inflated, this expansion increases the tire's internal pressure. The tire walls can only withstand certain pressure levels before they fail, leading to a blowout.
When pumping air into a tire, the volume first increases without much increase in pressure. But once the tire is full and the walls resist expansion (Figure 13.18), additional air leads to increased pressure.
This pressure can further increase with temperature changes. So, both when air is pumped into a tire and when a tire is exposed to heat, such as sunlight, the internal pressure can rise. This is why bicycle tires are susceptible to temperature changes; however, it's the increase in pressure due to the heat from the sun that can lead to a blowout.
The correct option is b) Hot air expands, increasing tire pressure.