What is Weight?

(d) calculate weight from the equation weight = mass × gravitational field strength.

 What is Weight?

Weight is a force that acts on a body when it is in a gravitational field. The magnitude of weight is the same on Earth, that is 10 N. The direction of this force acting on a body is downwards. As weight has a magnitude as well as a direction, it is a vector quantity.

How to Calculate Weight?

Weight is a quantity that depends on the strength of the gravitational field. The equation for calculating weight is W = mg, where W stands for weight, m is for mass and g for gravitational field strength. The value for g is constant on Earth, that is approximately 10 N/Kg. Thus what we need to calculate the weight of any object on Earth is to know the mass of that object.

We know that weight depends on gravitational field strength. This means that the weight of an object is different on Earth compared to the Moon, because the gravitational field strength of the Moon is different from the Earth.

Difference between Mass and Weight

The first difference between mass and weight is that mass is a scalar, while weight is a vector. The unit for mass is Kg, while the unit for weight is N.

Secondly, mass remains constant for a body, whether it is on Earth or Moon. This is so because the amount of matter in the body does not change whether it is on Earth or on Moon. On the other hand, as Weight is derived from gravitational field strength, it would be different on Moon compared to Earth.