Final answer:
The provided information does not directly answer the question about hydroplaning speeds; still, hydroplaning is a phenomenon explained by physics and related to fluid dynamics and friction.
Step-by-step explanation:
The question regarding the speed at which an ambulance will begin to hydroplane on a wet roadway is better addressed with principles from physics, specifically fluid dynamics and friction.
However, the provided reference information does not sufficiently relate to hydroplaning directly but instead appears to discuss the Doppler effect and stopping distances on wet and dry surfaces. To determine hydroplaning speed, one would typically apply the formula v = √(9 * r * h),
where v is the minimum hydroplaning speed in feet per second, r is the tire pressure in pounds per square inch, and h is the depth of water on the road in inches. It is important to note that factors such as tire tread and condition, vehicle weight, and speed will affect the actual hydroplaning speed.