WJEC GCSE Physics
WJEC GCSE Physics 2.2 Newton's Laws Exam Questions
Free WJEC GCSE Physics revision for 2.2 Newton's Laws: what you need to know, common mistakes and exam-style questions with answers. Covers inertia, Newton's first, second and third laws, resultant force, F = ma, weight and mass, air resistance and terminal speed.
Practise 2.2 Newton's Laws with past papers
Once you have learnt this topic, find the 2.2 Newton's Laws questions in real WJEC GCSE Physics past papers and mark them with the mark scheme. Doing lots of real questions is the quickest way to learn how examiners ask about each idea.
StemUp mark scheme flashcards
GCSE Physics Triple Science Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
From £7.99View flashcards
About WJEC GCSE Physics 2.2 Newton's Laws
Newton's laws in Unit 2 explain how forces change motion. You need to describe inertia and mass as a measure of it, state and apply Newton's three laws, and use F = ma with the resultant force. You must distinguish weight from mass and use W = mg with g about 10 N/kg on Earth. The topic covers motion through air, explaining how a falling object reaches terminal speed as air resistance increases. Investigating the terminal speed of a falling object, such as a paper cake case, is the specified practical. Examiners often ask for explanations of skydiver motion and for pairs of forces described by the third law.
What you need to know
- Newton's first law An object stays at rest or keeps moving at constant velocity unless a resultant force acts on it. This tendency is inertia, and mass is a measure of inertia.
- Newton's second law Resultant force = mass x acceleration (F = ma). A larger resultant force gives a larger acceleration; a larger mass gives a smaller acceleration for the same force.
- Newton's third law When object A exerts a force on object B, B exerts an equal and opposite force on A. The two forces act on different objects and are of the same type.
- Weight and mass Mass (kg) is the amount of matter and does not change with location. Weight (N) is the gravitational force: W = mg, with g about 10 N/kg on Earth.
- Terminal speed A falling object accelerates because weight is greater than air resistance. As speed increases, air resistance increases until it equals weight; the resultant force is zero and the object falls at constant terminal speed.
- Specified practical Drop paper cake cases (or similar) and measure the time to fall a set distance once at terminal speed. Investigate how mass or surface area affects terminal speed.
Common mistakes in 2.2 Newton's Laws
- Saying a moving object needs a resultant force to keep moving. With no resultant force it keeps moving at constant velocity.
- Describing third law pairs as forces acting on the same object, such as weight and the normal reaction on a book. Third law pairs act on different objects.
- Giving weight in kilograms. Weight is a force measured in newtons; mass is in kilograms.
- Saying a skydiver goes up when the parachute opens. The skydiver decelerates because air resistance becomes greater than weight, but still moves downwards.
Try three 2.2 Newton's Laws exam-style questions
1. A 1200 kg car has a driving force of 3000 N and resistive forces of 600 N. Calculate its acceleration. (3 marks)
Show the mark scheme answer
Resultant force = 3000 - 600 = 2400 N; a = F / m = 2400 / 1200; = 2 m/s2.
2. Calculate the weight of a 65 kg person on Earth. (g = 10 N/kg) (1 mark)
Show the mark scheme answer
W = 65 x 10 = 650 N.
3. Explain why a skydiver reaches terminal speed. (4 marks)
Show the mark scheme answer
Initially weight greater than air resistance so skydiver accelerates; as speed increases air resistance increases; eventually air resistance equals weight; resultant force is zero so speed is constant.
2.2 Newton's Laws FAQs
What does WJEC GCSE Physics 2.2 Newton's Laws cover?
It covers inertia, Newton's three laws of motion, resultant force and F = ma, the difference between weight and mass, W = mg, air resistance and terminal speed.
Which unit is Newton's Laws examined in?
It is examined in Unit 2: Forces, Space and Radioactivity, a 1 hour 45 minute written paper worth 45% of the GCSE, sat at foundation or higher tier. The Unit 3 practical assessment draws on the same practical skills.
How do I explain terminal speed fully?
Compare weight and air resistance at each stage, state what happens to the resultant force and acceleration, and finish when forces are balanced and speed is constant. Mention speed increasing air resistance.
