1. (Units) a unit of heat in the fps system equal to the quantity of heat required to raise the temperature of 1 pound of water by 1Â°F. 1 British thermal unit is equivalent to 1055.06 joules or 251.997 calories.
Quick Answer. A major factor that usually causes tire noise is the air chamber inside the tire. The large void that is filled with air acts as a giant resonance chamber. Thus, the tires are something like donut-shaped drums that generate a low-frequency hum when tires are rolling.
Belt noise: it is annoying and is usually a sign that something is not working properly under the hood of your vehicle. While the belt is often blamed for belt noise, the belt is rarely the actual cause. The No. 1 cause of belt noise is misalignment within the belt drive system. And there are two distinctively different types of belt noise, âChirpâ and âSquealâ. Each has its own unique characteristics, causes and solutions.