Mass and Weight - A Level Physics

Mass is defined as the amount of 'stuff' within an object. It remains constant regardless of location, whether on Earth, the Moon, or in deep space. The video mentions the Higgs field and particle as factors related to what causes mass.

Weight is the force an object experiences due to a gravitational field. It is calculated by multiplying mass by gravitational field strength (G). On Earth, G is approximately 9.81 Newtons per kilogram (N/kg) or meters per second squared (m/s²). This value can vary slightly depending on elevation.

Using the example of a 100 kg astronaut, the video illustrates that while their mass stays at 100 kg on the Moon, their weight changes due to the Moon's weaker gravitational field. The Moon's G is about 1.6 N/kg or m/s².

In summary, weight is measured in Newtons (as it's a force), while mass is measured in kilograms. The video emphasizes the importance of using correct terminology, as 'weight' is often used incorrectly in daily conversation when 'mass' is intended. A Newton meter measures weight, while a mass balance measures mass.