This definitions covers Key Definitions within Newton's Laws of Motion for GCSE Physics. Revise Newton's Laws of Motion in Forces for GCSE Physics with 24 exam-style questions and 15 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 9 of 15 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 9 of 15
Practice
24 questions
Recall
15 flashcards
📖 Key Definitions
Newton's First Law: An object remains at rest or moves at constant velocity unless a resultant force acts on it.
Newton's Second Law: The acceleration of an object is directly proportional to the resultant force and inversely proportional to its mass. F = ma.
Newton's Third Law: For every action there is an equal and opposite reaction — forces act on different objects simultaneously.
Inertia: The resistance of an object to a change in its motion. Greater mass = greater inertia.
Resultant force: The single force that has the same effect as all the individual forces acting on an object combined.
Keep building this topic
Read this section alongside the surrounding pages in Newton's Laws of Motion. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Newton's Laws of Motion
According to Newton's First Law, what happens to an object when there is no resultant force acting on it?
A spaceship is travelling through deep space far from any planets. The engines are switched off. Explain what will happen to the motion of the spaceship and why.
Quick Recall Flashcards
24 questions on Newton's Laws of Motion — practise free
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