1.3

Mass and weight

Cambridge IGCSE Physics (0625)  · Unit 1: Motion, forces and energy  · 10 flashcards

Mass and weight is topic 1.3 in the Cambridge IGCSE Physics (0625) syllabus , positioned in Unit 1 — Motion, forces and energy , alongside Physical quantities and measurement techniques, Motion and Density.  In one line: Mass is a measure of the quantity of matter in an object at rest relative to the observer. It is a scalar quantity and is measured in kilograms (kg).

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 show this topic across undefined questions worth 232 marks (around 3.6% of all Physics marks in those years).

The deck below contains 10 flashcards — 3 definitions — covering the precise wording mark schemes reward.  Use the 3 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

State what is meant by the term 'mass'

Mass is a measure of the quantity of matter in an object at rest relative to the observer. It is a scalar quantity and is measured in kilograms (kg).

What the Cambridge 0625 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. State State that mass is a measure of the quantity of matter in an object at rest relative to the observer
  2. State State that weight is a gravitational force on an object that has mass
  3. Define Define gravitational field strength as force per unit mass; recall and use the equation
  4. Know Know that weights (and masses) may be compared using a balance
  5. Describe Describe, and use the concept of, weight as the effect of a gravitational field on a mass Supplement
Definition Flip

State what is meant by the term 'mass'.

Answer Flip

Mass is a measure of the quantity of matter in an object at rest relative to the observer. It is a scalar quantity and is measured in kilograms (kg).

Key Concept Flip

A small toy car and a large van are both at rest. Explain why the van has more mass than the toy car.

Answer Flip

Mass is a measure of the quantity of matter in an object. The van has more mass than the toy car because the van contains a greater quantity of matter (more atoms and molecules) than the toy car.

Definition Flip

Define weight. State what type of force weight is.

Answer Flip

Weight is the gravitational force acting on an object due to its mass. Weight is a type of force.

Key Concept Flip

A small toy car has a mass of 0.15 kg. Calculate the weight of the toy car on Earth where the gravitational field strength is 9.8 N/kg.

Answer Flip

Weight (W) = mass (m) × gravitational field strength (g)
W = 0.15 kg × 9.8 N/kg
W = 1.47 N

Weight is calculated by multiplying the mass of an object by the gravitational field strength.

Key Concept Flip

A brick has a mass of 2.0 kg. The gravitational field strength on Earth is 9.8 N/kg. Calculate the weight of the brick.

Answer Flip

Formula: Weight (W) = mass (m) x gravitational field strength (g)
Working: W = 2.0 kg x 9.8 N/kg = 19.6 N
Answer: The weight of the brick is 19.6 N. The weight is the force due to gravity acting on the mass.

Definition Flip

State what is meant by the term 'gravitational field strength'.

Answer Flip

Answer: Gravitational field strength is the force of gravity acting per unit mass.

Key Concept Flip

A student places an unknown mass on one side of a balance. To balance it, they place a 0.5 kg mass and a 0.15 kg mass on the other side. Calculate the mass of the unknown object.

Answer Flip

Mass is compared using a balance. The masses on each side must be equal for the balance to be level.

Total mass on balancing side = 0.5 kg + 0.15 kg = 0.65 kg

Therefore, the unknown mass = 0.65 kg

Answer: 0.65 kg

Key Concept Flip

Explain how a simple balance can be used to compare the masses of two objects.

Answer Flip

A simple balance works on the principle of moments. Place one object on each side of the balance. If the balance is level, the moments on each side are equal, meaning the masses are equal. If one side is lower, its mass is greater. The greater the difference in height/angle, the greater the mass difference between the objects.

Key Concept Flip

A book has a mass of 0.75 kg. The gravitational field strength on Earth is 9.8 N/kg. Calculate the weight of the book.

Answer Flip

Weight (W) = mass (m) x gravitational field strength (g)
W = 0.75 kg x 9.8 N/kg
W = 7.35 N

Explanation: Weight is the force experienced by a mass due to gravity. It's calculated by multiplying the object's mass by the local gravitational field strength.

Key Concept Flip

Describe how weight is related to mass and the gravitational field.

Answer Flip

Weight is the force exerted on an object due to gravity. It is directly proportional to both the object's mass and the gravitational field strength at the object's location. A larger mass or a stronger gravitational field will result in a greater weight.

Review the material

Read revision notes with definitions, equations, and exam tips.

Read Notes

Test yourself

Practice with MCQ questions to check your understanding.

Take Physics Quiz
1.2 Motion 1.4 Density

Key Questions: Mass and weight

State what is meant by the term 'mass'.

Mass is a measure of the quantity of matter in an object at rest relative to the observer. It is a scalar quantity and is measured in kilograms (kg).

Define weight. State what type of force weight is.

Weight is the gravitational force acting on an object due to its mass. Weight is a type of force.

State what is meant by the term 'gravitational field strength'.

Answer: Gravitational field strength is the force of gravity acting per unit mass.

Tips to avoid common mistakes in Mass and weight

More topics in Unit 1 — Motion, forces and energy

Mass and weight sits alongside these Physics decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0625 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

mass weight gravitational field strength gravity g W=mg kilogram newton

Key terms covered in this Mass and weight deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

What is meant by the term 'mass'
Weight. State what type of force weight is
What is meant by the term 'gravitational field strength'

Related Physics guides

Long-read articles that go beyond the deck — cover the whole subject's common mistakes, high-yield content and revision pacing.

How to study this Mass and weight deck

Start in Study Mode, attempt each card before flipping, then rate Hard, Okay or Easy. Cards you rate Hard come back within a day; cards you rate Easy push out to weeks. Your progress is saved in your browser, so come back daily for 5–10 minute reviews until every card reads Mastered.