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.
1. A Slapping Noise that Increases Tempo with Vehicle Speed. This is the sound of a dying tire. Its tread is separating from the carcass of the tire. As the tread leaves the tires, it may turn into a giant steel-reinforced Weed Eater. It can cause massive damage to the vehicle's bodywork as it leaves the tire. So if you hear it, don't keep driving. 2.