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.
If the brake grinding is caused by worn down brake pads, immediate repair is vital. Once the brake pads become completely worn down, it can cause brake failure. Driving with worn down brake pads can also cause the caliper, drum or rotor damage which will end in costly repairs for the car owner. Another less common reason for brakes making a grinding noise is something becoming lodged in the caliper.