Which of the following is the smallest amount of water in which a car can hydroplane?

The smallest amount of water in which a car can hydroplane is 1/10 of an inch. Hydroplaning occurs when a vehicle's tires lose contact with the road surface due to a layer of water, causing the tires to slide on the water rather than on the road. The threshold for hydroplaning is quite low; even a small amount of water can create enough of a slippery surface that the tires cannot maintain grip.

Understanding the mechanics of hydroplaning involves recognizing that factors such as tire tread depth, tire pressure, and speed can influence the onset of hydroplaning. While hydroplaning can begin to occur with as little as 1/10 of an inch of water, the risk increases significantly with higher speeds or worn tires, emphasizing the importance of safe driving practices in wet conditions.

Knowing the amount at which hydroplaning starts can help drivers understand the hazards of driving in wet weather and encourage them to adjust their speed and increase following distances appropriately when rain is present.