Pressure points The Institute of Physics says that recent errors in A-level physics unfairly perpetuate the myth that physics is a difficult subject. (Courtesy: shutterstock/monkey business images) ...

Air molecules colliding with a surface cause atmospheric pressure. Atmospheric pressure at sea level is about 101,000 Pa (101 kPa) but just 27,000 Pa (27 kPa) at the cruising altitude of a passenger ...

Speed, density and pressure are examples of compound measures which means they are made up of two or more other measures. For example, speed is made up of distance and time. To convert the units of ...