Common Misconceptions
Part of Newton's Laws of Motion · GCSE GCSE Physics revision
This common misconceptions covers Common Misconceptions 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 10 of 15 in this topic. Use this common misconceptions to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 15
Practice
24 questions
Recall
15 flashcards
⚠️ Common Misconceptions
Misconception 1: "Weight and normal force are a Newton's Third Law pair"
They are NOT a Third Law pair! Both weight and normal force act on the SAME object (the book on the table). A true Third Law pair: the book pulls the Earth upward with a gravitational force equal to the book's weight, and the Earth pulls the book downward. For the table: the book pushes the table downward, and the table pushes the book upward — that IS a Third Law pair.
Misconception 2: "If two forces are equal and opposite, they must be a Third Law pair"
Not necessarily! Weight and normal force on a book are equal and opposite but are NOT a Third Law pair (same object, different types of force — gravity vs contact). True Third Law pairs: same type of force, different objects, always equal and opposite.
Misconception 3: "F = ma means more force always means more speed"
F = ma links force to ACCELERATION (rate of change of velocity), not speed directly. A force in the OPPOSITE direction to motion causes deceleration, reducing speed. The direction of the resultant force determines the direction of acceleration — which may increase or decrease speed.
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
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