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.
The most common cause of tire separation is contact with a curb or pothole. The layers of the tire get pinched, and air inside the tire gets between them. Essentially, the tire isnât totally round anymore and causes a vibration. The separation can be a safety concern as the tire is significantly weaker at that spot. A lumpy driving feeling at low speeds progresses to a fast vibration at higher speeds when a tire separation occurs.