Final answer:
Bicycle tires seem higher in the summer because the pressure of the trapped air increases with rising temperature, due to the gas law that states pressure increases when temperature does if volume is constant.
Step-by-step explanation:
Bicycle tires seem higher in pressure during the summer than in the winter primarily due to the effect of temperature on gases. According to the gas laws, specifically Gay-Lussac's law, the pressure of a gas increases when the temperature increases if the volume of the gas remains constant. Since the volume of a bicycle tire is relatively fixed, the increased temperature in the summer leads to an increase in pressure inside the tire.
When a bicycle tire is fully inflated, it contains a certain amount of air at a particular pressure and temperature. If the temperature rises, the air molecules inside the tire move faster, slamming into the walls of the tire with more force, thereby increasing the pressure. For instance, if a tire's pressure is 7.00 × 105 Pa at 18.0°C, the pressure will rise when the temperature increases to 35.0°C, assuming no air escapes and the tire's volume remains unchanged. This principle not only applies to bicycle tires but also to car tires and other enclosed gases exposed to temperature changes.
To further explain the importance of temperature and pressure in everyday situations, in icy conditions, tires with more friction are preferable as they provide better traction, reducing the risk of slipping. This is an example where an increase in friction is beneficial for safety.