Final answer:
The correct answer is option: the road is most slippery at the beginning of rainfall on a hot day due to the mix of rainwater and oil residue on the road surface.
Step-by-step explanation:
The correct answer is option: when it starts to rain on a hot day, the road is most slippery at the beginning of the rain. This phenomenon occurs because the rainwater mixes with oil residue on the road surface, which hasn't yet washed away. The first few minutes of rainfall can create this slippery mixture, increasing the risk of vehicles skidding.
Moreover, during hot days, roads can become even more slippery as heat causes oils to rise to the road surface. When the rain starts, it floats these oils back on top, leading to the most slippery conditions. In contrast, continuous heavy rainfall eventually washes away the oil, making the road less slippery.
Therefore, driving cautiously and reducing speed is advisable when it begins to rain, especially on a hot day. Additionally, selecting tires with adequate tread for wet conditions can improve traction and reduce the risk of hydroplaning, as more friction is desirable in such situations, similar to the importance of using winter tires on icy roads.
The correct answer is option Physics. When it starts to rain on a hot day, the road becomes slippery due to a decrease in friction between the tires and the road surface. This is because the rainwater acts as a lubricant between the tires and the road, reducing the frictional force that keeps the tires gripped to the road.
One example where more friction is desirable is during braking in a car. When you apply the brakes, the friction between the brake pads and the rotors helps to slow down the car and bring it to a stop.
In summary, when it starts to rain on a hot day, the road becomes the most slippery due to a decrease in friction between the tires and the road.