Mass and weight Flashcards – Cambridge IGCSE (9–1) Physics 0972 (Extended) (2026–2028)

What is mass?

A measure of the quantity of matter in an object at rest relative to the observer.

What unit is used to measure mass?

The kilogram (kg).

How does moving an object to a different gravitational field affect its mass?

Its mass does not change simply because the gravitational field changes.

How can a balance be used to compare the masses of two objects?

It compares their weights. In the same gravitational field, equal weights indicate equal masses.

What is weight?

The gravitational force on an object that has mass.

What unit is weight measured in?

Newtons (N).

In which direction does an object's weight act?

Towards the body exerting the gravitational attraction.

What two factors determine an object's weight?

Its mass and the gravitational field strength at its location.

What is gravitational field strength, and how is it expressed using weight $W$ and mass $m$?

Gravitational force per unit mass at a location: $g = \frac{W}{m}$.

What unit is gravitational field strength measured in?

Newtons per kilogram ($\mathrm{N/kg}$).

How is gravitational field strength related to the acceleration of free fall?

It is equal to the acceleration of free fall at that location, measured in $\mathrm{m/s^2}$.