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.
show more When I am driving over bumps on the road there is a rattling noise coming from the back of the car. Is does not make the noise when I shake the car from the back, and doesn't make the noise when accelerating, only when going over bumps or on rough parts of the road. The noise is not continuous, and the rattle... show more When I am driving over bumps on the road there is a rattling noise coming from the back of the car. Is does not make the noise when I shake the car from the back, and doesn't make the noise when accelerating, only when going over bumps or on rough parts of the road. The noise is not continuous, and the rattle seems to stop when braking.